KOMPENDIUM
KAJIAN LINGKUNGAN
DAN
PEMBANGUNAN
BIODEGRADASI
&
COMPOSTING
Dikoleksi oleh:
Soemarno, pdklp-ppsub 2012
DEKOMPOSISI BAHAN ORGANIK
Bahan organik merupakan bahan-bahan yang dapat diperbaharui, didaur ulang,
dirombak oleh bakteri-bakteri tanah menjadi unsur yang dapat digunakan oleh
tanaman tanpa mencemari tanah dan air.
Bahan organik tanah merupakan penimbunan dari sisa-sisa tanaman dan
binatang yang sebagian telah mengalami pelapukan dan pembentukan kembali.
Bahan organik yang sedang mengalami dekomposisi aktif akan menjadi mangsa
bagi jasad mikro. Sebagai akibatnya bahan tersebut berubah terus dan tidak
mantap sehingga harus selalu diperbaharui melalui penambahan sisa-sisa
tanaman atau binatang.
Komposisi Biomassa / Bahan Organik
Menurut Waksman (1948), biomass bahan organik yang berasal dari biomass
tumbuhan, terdiri dari: (1) air (75%) dan (2) biomass kering (25%).
Komposisi biokimia bahan organik dari biomass kering tersebut, terdiri dari:
karbohidrat (60%), lignin (25%), protein (10%), dan lemak, lilin dan tanin (5%).
Karbohidrat penyusun biomass kering tersebut, terdiri dari: gula dan pati (1% s/d- 5%), hemiselulosa (10% -s/d- 30%), dan selulosa (20% -s/d- 50%).
Berdasarkan kategori unsur hara penyusun biomass kering, terdiri dari: Karbon
(C = 44%), Oksigen (O = 40%), Hidrogen (H = 8%), dan Mineral (8%).
contoh komposisi kimiawi jerami padi dan serealia. Selulose dan
hemiselulose merupakan komponen utama dari jerami padi.
BioDegradasi Residu Tanaman
Bahan organik residu tanaman mengandung 15-60 % sellulose, 10-30 %
hemicellulose, 5-30 % lignin, 2-15 % protein dan 10 % gula, asam amino
dan asam-asam organik. Sellulose terdapat dalam bentuk semi-crystalline
dengan berat molekul 106 dan mempunyai unit-unit glucose dengan ikatan
B(1-4). Rantai-rantai glucose diikat bersama dengan ikatan-hidrogen.
Kompleks enzim Cellulase menghancurkan sellulose menjadi disaccharidecellobiose yang dihidrolisis lebih lanjut oleh ensim cellobiase menjadi
glucose. Hemicelluloses merupakan polimer dari hexoses, pentoses dan
kadangkala asam-asam uronat, bersama dengan monomer seperti xylose
dan mannose. Pectin merupakan salah satu contoh dari hemicelluloses dan
merupakan komponen penting dari middle-lamella pada dinding sel. Pectin
dapat dihancurkan oleh enzim pectinase yang merupakan kompleks dari
beberapa jenis enzim.
Proses dekomposisi bahan organik melalui 3 reaksi, yaitu:
1. Reaksi enzimatik atau oksidasi enzimatik, yaitu: reaksi oksidasi senyawa
hidrokarbon yang terjadi melalui reaksi enzimatik menghasilkan produk
akhir berupa karbon dioksida (CO2), air (H2O), energi dan panas.
2. Reaksi spesifik berupa mineralisasi dan atau immobilisasi unsur hara
essensial berupa hara nitrogen (N), fosfor (P), dan belerang (S).
3. Pembentukan senyawa-senyawa baru atau turunan yang sangat resisten
berupa humus tanah.
Urutan kemudahan dekomposisi dari berbagai bahan
penyusun bahan organik tanah dari yang terdekomposisi
paling cepat sampai dengan yang terdekomposisi paling
lambat, adalah sebagai berikut:
1. gula, pati, dan protein sederhana,
2. protein kasar (protein yang leih kompleks),
3. hemiselulosa,
4. selulosa,
5. lemak, minyak dan lilin, serta
6. lignin.
BAHAN ORGANIK DAN KOMPOS
Kompos adalah hasil penguraian parsial/tidak lengkap dari campuran bahanbahan organik yang dapat dipercepat secara artifisial oleh populasi berbagai
macam mikroba dalam kondisi lingkungan yang hangat, lembap, dan aerobik
atau anaerobik.
Pengomposan adalah proses dimana bahan organik mengalami penguraian
secara biologis, khususnya oleh mikroba-mikroba yang memanfaatkan bahan
organik sebagai sumber energi. Membuat kompos adalah mengatur dan
mengontrol proses alami tersebut agar kompos dapat terbentuk lebih cepat.
Proses ini meliputi membuat campuran bahan yang seimbang, pemberian air
yang cukup, mengaturan aerasi, dan penambahan aktivator pengomposan.
Proses Pengomposan
Proses pengomposan akan segera berlansung setelah bahan-bahan mentah
dicampur. Proses pengomposan secara sederhana dapat dibagi menjadi dua
tahap, yaitu tahap aktif dan tahap pematangan. Selama tahap-tahap awal
proses, oksigen dan senyawa-senyawa yang mudah terdegradasi akan
segera dimanfaatkan oleh mikroba mesofilik.
Suhu tumpukan kompos akan meningkat dengan cepat. Demikian pula akan
diikuti dengan peningkatan pH kompos. Suhu akan meningkat hingga di atas
50o - 70o C. Suhu akan tetap tinggi selama waktu tertentu. Mikroba yang aktif
pada kondisi ini adalah mikroba Termofilik, yaitu mikroba yang aktif pada suhu
tinggi. Pada saat ini terjadi dekomposisi/penguraian bahan organik yang
sangat aktif. Mikroba-mikroba di dalam kompos dengan menggunakan
oksigen akan menguraikan bahan organik menjadi CO2, uap air dan panas.
Setelah sebagian besar bahan telah terurai, maka suhu akan berangsurangsur mengalami penurunan.
Pada saat ini terjadi pematangan kompos tingkat lanjut, yaitu pembentukan
komplek liat humus. Selama proses pengomposan akan terjadi penyusutan
volume maupun biomassa bahan. Pengurangan ini dapat mencapai 30 – 40%
dari volume/bobot awal bahan.
Sumber:
http://id.wikipedia.org/wiki/Kompos ….. Diunduh 20/4/2012
BAHAN ORGANIK TANAH (BOT)
BOT = SOM - organic matter in a soil that cannot be recognized as plant
material under a light microscope.
* Biota hidup dalam tanah. (Mikroba Tanha)
* Residu tumbuhan, binatang dan mikroba yang sedang mengalami
dekomposisi.
* Bahan organik yang reistem terhadp dekomposisi lanjut.
.
.
.
.
1019 kg C on earth most in sediments
and rocks, fossil fuels, and DIC & POM
in the oceans
Biogeochemical cycling C SOM ~1
x 1015 kg +
CO2 (atmosphere) ~ 5 x 1014kg
living organisms ~ 5 x 1014 kg.
BAHAN ORGANIK TANAH
At 1 – 10(vol)% C in the soil, 1 hectare (100m x 100m; 2.47 acres) to a depth
of 15 cm (plough depth) has about 15 – 150 tonnes C.
Consider residence times.
The most significant input to SOM is plant residues;
~ 11 tonne ha-1 yr-1 for tropical rain forests, TR ~ 1.4 - 14 yr.
~ 6 tonne ha-1 yr-1 for temperate forests, TR ~ 2.5 - 25 yr.
~3 tonne ha-1 yr-1 for temperate grasslands, TR ~ 5 - 50 yr, and
<1 tonne ha-1 yr-1 for deserts, >15 – 150 yr.
60 - 70% of this comes from plant roots (rhizo derived),
70% of plant residues decompose within 1 year. Most of the C in soils is in
the resistate (humic) form (~70%).
BAHAN ORGANIK TANAH
At 1 – 10(vol)% C in the soil, 1 hectare (100m x 100m; 2.47 acres) to a depth
of 15 cm (plough depth) has about 15 – 150 tonnes C.
1.
Functions of SOM:
Binds particles to form soil aggregates (hinders soil erosion;
soils need approximately 4% C to be structurally stable).
2.
Degrading organics a source of nutrients to soil - N, P, S, B,
metals (Cu, Zn, Mg, Ca, Fe, Mo, Mn).
3.
Contributes to soil pH.
4.
Has a high Cation Exchange Capacity - ~300meq/100g SOM
(2:1 clays of 100meq/100 g clay, 1:1 clay 10meq/100g clay).
5.
Controls transport/availability of metals via complexation &
adsorption reactions – Kf large for humics, smaller for lower
MW carboxylic acids, amino acids, and organic bases
(NTA3- as model for complexation).
6.
Enhances water retention.
7.
Gives soil a darker colour (heat adsorption/retention).
Peranan bahan organik terhadap perubahan sifat fisik tanah, meliputi:
1. Stimulan terhadap granulasi tanah,
2. Memperbaiki struktur tanah menjadi lebih remah,
3. Menurunkan plastisitas dan kohesi tanah,
4. Meningkatkan daya tanah menahan air sehingga drainase tidak
berlebihan, kelembaban dan temperatur tanah menjadi stabil,
5. Mempengaruhi warna tanah menjadi coklat sampai hitam,
6. Menetralisir daya rusak butir-butir hujan,
7. Menghambat erosi, dan
8. Mengurangi pelindian (pencucian/leaching).
BAHAN ORGANIK TANAH.
Soil
Nutrients,
trace elements,
inorganics
Water
20 - 30%
CO2, CH4, H2O
SOM
heat
Mineralized
organics
(humics, peat, oils,
coal).
SOM
0 - 10%
Air
20 - 30%
45%
inorganic
Degrading plant materials (30%),
& physically and chemically resistant
organics (70%)
25% dry matter
* Sugars & starches - foods.
60%
* Proteins (10%)
* Cellulose & hemicelluloses structural materials.
* Lipids - fats/waxes/steroids/etc. (5%)
*Lignins - structural materials (25%)
Increasingly resistant to
weathering
44% C
40% O
8% H
8% ash
wt %
C6H12.8O6
. Waste Manag. 2007;27(10):1317-27. Epub 2006 Nov 21.
Composting anaerobic and aerobic sewage sludges using two proportions of
sawdust.
Banegas V, Moreno JL, Moreno JI, García C, León G, Hernández T.
Sawdust has been proven to be a good
bulking agent for sludge composting;
however, studies on the most suitable
ratio of sludge:sawdust for sludge
composting and on the influence of the
sludge nature (aerobic or anaerobic) on
the composting reaction rate are scarce.
In this study two different
sewage sludges (aerobic,
AS, and anaerobic, ANS)
were composted with wood
sawdust (WS) as bulking
agent at two different ratios
(1:1 and 1:3 sludge:sawdust,
v:v).
Aerobic sludge piles showed significantly higher microbial activity than those of
anaerobic sludge, organic matter mineralization rates being higher in the AS
mixtures. The lowest thermophilic temperatures during composting were registered
when the anaerobic sludge was mixed with sawdust at 1:1 ratio, suggesting the
presence of substances toxic to microorganisms.
This mixture also showed the lowest decreases of ammonium during composting. All
this matched with the inhibitory effect on the germination of Lepidium sativum seeds
of this mixture at the first stages of composting, and with its low values of microbial
basal respiration. However, the ANS+WS 1:3 compost developed in a suitable way;
the higher proportion of bulking agent in this mixture appeared to have a diluting
effect on these toxic compounds.
Both the proportions assayed allowed composting to develop adequately in the case
of the aerobic sludge mixture, yielding suitable composts for agricultural use.
However, the ratio 1:1 seems more suitable because it is more economical than the
1:3 ratio and has a lower dilution effect on the nutritional components of the
composts.
In the case of the anaerobic sludge with its high electrical conductivity and
ammonium content, and likely presence of other toxic and phytotoxic substances, the
1:3 ratio is to be recommended because of the dilution effect.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/17118642 ….. Diunduh 28/4/2012
BAHAN ORGANIK TANAH (bot) :
Carbohydrates (CH2O) polyhydroxyaldehydes or ketones
or substances that hydrolyse to give these (Solomons,
Fundimentals of Organic Chemistry, 1994, Chapter 22).
Sugars are mono- or di-saccharides
 D(+) glucopyranose
Polymerize to
give starch
Polymerize
(dehydration) to
give cellulose
 D(+) glucopyranose
oth the hemiacetal OH &
the C6 CH2OH
on the same face.
 1 - 4 glycosidic linkages
* Long unbranched chains of up to 15,000 glucose units; alternate
units turned over – polysacharides.
* Up to 40 chains held together by H-bonds to form an insoluble,
rigid, fibers which serve as the structural materials in the cell
walls of plants and some animals.
*Approximately 50% of C in the biosphere is cellulose. Very
slowly degraded.
Waste Manag. 2006;26(12):1370-6. Epub 2005 Dec 13.
Changes in organic matter composition during composting of two digested
sewage sludges.
Hernández T, Masciandaro G, Moreno JI, García C.
Changes in the chemical and chemicalstructural composition of the organic matter
of two different sewage sludges (aerobic and
anaerobic) mixed with sawdust (1:1 and 1:3,
v/v) during composting were determined by
monitoring chemical and microbiological
parameters as well as by pyrolysis-gas
chromatography.
Composting was carried out in
periodically turned outdoor piles,
which were sampled for analysis
1, 30, 60 and 90 days after the
beginning of the composting
process. Both volatile organic
matter and the water soluble C
fraction decreased during
composting, indicating that the
more labile C fractions are
mineralized during the process.
Microbial activity as measured by microbial respiration (CO(2) evolved from compost
samples during incubation) also decreased with composting, reflecting the more
stable character of the resulting compost. No major differences were observed
between the four composts studied as regards their chemical-structural
characteristics. The acetonitrile, acetic acid and phenol pyrolytic fragment tended to
increase with composting. Although the final composts were more aromatic in nature
than the starting materials, a low degree of humification was observed in all four
composts studied, as determined by their high proportion of polysaccharides and alkyl
compounds.
For this reason, the relationship between pyrolytic fragments, such as
benzene/toluene or benzene+toluene/pyrrol+phenols, which are used as indices of
humification for soil organic matter, are not of use for such poorly evolved sludge
composts; instead, ratios that involve carbohydrate derivatives and aromatic
compounds, such as furfural+acetic/benzene+toluene or acetic/toluene, are more
sensitive indices for reflecting the transformations of these materials during
composting. Both the chemical and microbiological parameters and pyrolytic analysis
provided valuable information concerning the nature of the compost's organic matter
and its changes during the composting process.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/16356705 ….. Diunduh 28/4/2012
BAHAN ORGANIK TANAH (bot):
Carbohydrates.
 D(+) glucopyranose
 D(+) glucopyranose
1-6
glucosidic
linkage
Polymerize to give
starch: the food
reserve in plants
1-4
glucosidic
linkage
Starch - a major nutrient for animals.
Enzymically assisted digestion involves the hydrolysis of 
1 - 4 glycosidic links to produce oligiosaccharides (a few
linked monosaccharides containing the 1-6 linkages).
Further hydrolysis produces monosaccharides.
. Chemosphere. 2007 Feb;66(11):2166-76. Epub 2006 Nov 27.
Changes in the chemical composition of water-extractable organic matter
during composting: distribution between stable and labile organic matter
pools.
Said-Pullicino D, Kaiser K, Guggenberger G, Gigliotti G.
Aerobic decomposition and
stabilization of organic matter during
the composting of waste materials is
primarily due to the biochemical
transformation of water-soluble
compounds in the liquid phase by
the microbial biomass.
For this reason water-soluble
organic matter represents the most
active fraction of compost, both
biologically and chemically, and
thus should directly reflect the
biochemical alteration of organic
matter. This work aims to elucidate
the microbial-mediated processes
responsible for the distribution of
soluble organic matter between
stable and labile pools with
composting time.
Accordingly, chemical analysis as well as UV absorption,
and 1H and 13C-NMR spectroscopy of samples
collected during the industrial composting of urban
waste revealed microbial induced transformation of
water-extractable organic matter over time.
The chemical composition changed from labile,
hydrophilic, plant-derived organic compounds in the
beginning to predominately stable, hydrophobic moieties
comprising lignin-derived phenols and microbiallyderived carbohydrates at later stages of composting.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/17125814 ….. Diunduh 28/4/2012
Soil Organic matter (SOM) :- Lignins
25% of SOM
The woody tissues of plants and the major material
binding cells together.
Water repellent.
As trees grow it impregnates the cells and kills them by
stopping water and nutrient transfer across the cell walls.
Highly aromatic polymers (MW - 2000 106) based on phenylpropane monomers.
Many functional groups,
acidic, colour,
high complexing capacity.
Bioresour Technol. 2005 Mar;96(4):471-8.
Characterization of natural organic matter (NOM) derived from sewage sludge
compost. Part 1: chemical and spectroscopic properties.
Zbytniewski R, Buszewski B.
In this study changes in the
properties of natural organic matter
(NOM) were studied during
composting of sewage sludge in a
laboratory experiment using the pile
method.
Typical physicochemical
parameters were measured
during 53 days of composting
including humic fractions.
The effects of humification on
the molecular properties of
humic acids (HA) were
investigated by 13C CP/MAS
NMR spectroscopy.
On the basis of chemical analyses, 53 days of composting sewage sludge
with structural material can be divided into three phases:
(i) domination of rapid decomposition of non-humic, easily biodegradable
organic matter (two to three weeks), (ii) domination of organic matter
humification and formation of polycondensed, humic-like substances (the
next two weeks), (iii) stabilization of transformed organic material and
weak microbial activity.
Spectroscopic characterization (13C NMR) of compost humic acids
reveals changes in their structures during maturation. The changes are
highly correlated with the processes taking place in bulk compost.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/15491829 ….. Diunduh 28/4/2012
KANDUNGAN PROTEIN BOT:
10% BOT
* The most diverse of the biopolymers
(starches, proteins and nucleic acids)
* Functions: hormones, enzymes,
antibodies, haemoglobin, skin, hair,
bone, muscles, tendons, ...
(Solomons,
chapter 24, p 9745)
* Provide N, S on degradation
H2O
* High molecular weight polyamides: 22
-amino acids. MW > 104.
BAHAN ORGANIK TANAH :
Lipids = 5% SOM
Operationally defined as the compounds of plants that can
be extracted into non-polar solvents – very diverse.
Waxes: esters of fatty acids and alcohols
Terpenes: molecules based on 2, 3, 4 or 5
isoprene {C=C(C)C=C} units.
Essential oils, natural rubbers, carotenes.
Steroids
cholester
ol
. Bioresour Technol. 2009 Dec;100(23):5827-33. Epub 2009 Jun 26.
Influence of bulking agent on sewage sludge composting process.
Yañez R, Alonso JL, Díaz MJ.
Four types of compost, consisting
of mixtures of Acacia dealbata (A)
with sewage sludge (SS) were
studied in a laboratory reactor.
Composting time was 80 days
and parameters monitored
over this period included
temperature, organic matter,
pH, CO(2), O(2), C/N ratio,
Kjeldahl-N, as well as maturity
indexes.
All the studied parameters were influenced by the bulking amount used.
The highest profile temperature measured was for the A/SS 1/2 (w/w)
mixture that reached a maxima temperature of 67 degrees C and lower
maximum temperatures of 52, 48 and 46 degrees C were observed for
A/SS 1/3, 1/1 and 1/0 composts, respectively.
The kinetic model used showed that a descent of sewage sludge in the
composting mixtures favored the enzyme-substrate affinity. However, an
increase in depending on the parameters of the process factors was
observed when the sewage sludge ratio was increased in mixtures.
The optimal amounts of sewage sludge for co-composting with Acacia
indicate that moderate amounts of sludge (1/1) would be the best
compromise.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/19560348 ….. Diunduh 28/4/2012
BAHAN ORGANIK TANAH: LEMAK
Triacylglycerols: Animal
fats and vegetable oils.
Formed by condensation
between glycerol and
various fatty acids
(c12 – C20).
Energy reserves in
animals.
Acyl groups can be saturated, unsaturated or polyunsaturated.
Oils > 70% unsaturated acyl groups. Fats < 40% unsaturated.
Phospholipids: One fatty acid replaced by a
phosphate linked to an alcohol - OPO(OH)OR".
Eg of R". -OCH2CH2N(CH3)3+ - choline;
Polar and non-polar ends; sources of P and N on
degradation.
BAHAN ORGANIK TANAH : NUCLEIC ACIDS
a purine
: adenine
pentose phosphate
backbone
a pyrimidine
base:
thyamine
guanine
Nucleic acids: (Solomons, Chapter 25, p1017) polymers of
nucleotides (phosphate, ribose or deoxyribose and a purine or a
pyrimidine base. Degrade to a base, phosphate and a sugar.
Adenosine triphosphate
(ATP): energy transmitting
molecules. Lose PO43- to give
ADP and AMP and energy for
biomolecule fromation.
Waste Manag Res. 2009 Aug;27(5):409-55. Epub 2009 Jul 7.
Microbial methane oxidation processes and technologies for mitigation of
landfill gas emissions.
Scheutz C, Kjeldsen P, Bogner JE, De Visscher A, Gebert J, Hilger HA, HuberHumer M, Spokas K.
Landfill gas containing methane
is produced by anaerobic
degradation of organic waste.
Methane is a strong
greenhouse gas and landfills
are one of the major
anthropogenic sources of
atmospheric methane.
Landfill methane may be
oxidized by methanotrophic
microorganisms in soils or
waste materials utilizing
oxygen that diffuses into the
cover layer from the
atmosphere
. The methane oxidation process, which is governed by several
environmental factors, can be exploited in engineered systems
developed for methane emission mitigation.
Mathematical models that account for methane oxidation can be
used to predict methane emissions from landfills.
Additional research and technology development is needed
before methane mitigation technologies utilizing microbial
methane oxidation processes can become commercially viable
and widely deployed.
Sumber:
http://www.ncbi.nlm.nih.gov/pubmed/19584243 ….. Diunduh 28/4/2012
BAHAN ORGANIK TANAH : The Resistant Fraction.
70% of SOM is the chemically & physically resistant organics.
Derived in some way from the plant residue inputs 
* similar structural units to the biomolecules,
* similar functional groups but not readily hydrolysed or oxidised.
* not clearly structurally defined (nor properties). Depend on inputs
and location: there is no one “resistant SOM”.
•Main contributor to many SOM properties:
CEC (150 - 300 meq/100g), complexing capacity, soil pH,
water retention (~ 80% of its own weight), colour (brown/black).
Acidic & phenolic
functional groups
A suggested
structure.
colour
Clay
particle
Fe(OH)3
coating
Protein
residue
Carbohydrate
residue
Lignin
residue
colour
Has a high MW (>103), strongly adsorbed to particle
surfaces, highly oxidised, extensively conjugated.
. Appl Environ Microbiol. 1985 December; 50(6): 1526–1530.
Effect of Temperature on Composting of Sewage Sludge
Kiyohiko Nakasaki, Makoto Shoda,* and Hiroshi Kubota
The effect of temperature on the
composting reaction of sewage
sludge was investigated at 50,
60, and 70°C.
The total amount of CO2
evolved and the final
conversion of volatile matter
were maximum at 60°C.,
suggesting that the optimal
temperature for composting
was around 60°C.
The specific CO2 evolution rate (moles of CO2 evolved per hour
per viable cell) was maximum at 70°C.
The isolated thermophilic bacterium which was dominant at
60°C but did not grow at 70°C showed that the rate of O2
consumption measured on the agar plate at 70°C was four times
higher than that at 60°C.
This showed that the energy yielded from catabolism is rather
uncoupled with the anabolism at 70°C in the metabolism of
microorganisms indigenous in the compost.
A higher respiratory quotient was observed at 70°C than at any
other temperature.
Sumber: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC238792/ ….. Diunduh 28/4/2012
KARAKTERISASI SUBSTANSI HUMIK
a) Isolation. Operationally defined by isolation procedure (cf lipids).
Soil
1. HCl:
2. 0.5M NaOH
CO3 CO2
24 - 48 hrs, N2 atm,
-
3. Centrifuge
10g soil/dm-3 caustic
** Elemental
analyses (C, H,
N, S: O by
difference) on an
ash free, dry
weight basis
a: insoluble
HUMIN
Soluble phase
1. 0.5M HCl 24hrs.
2. centrifuge
Soluble Fulvic
Acid
* yellow/red solution
* purify on a cation
exchange resin
**
* more O
* more
saturated
C
H
O
N
S
mole
wt% mole% ratio
45
3.8
1.4
5
5
1.8
45
2.8
1
2
0.14
2
0.06
C13H18O10
Insoluble
Humic Acid
**
mole
wt% mole% ratio
C 54
4.5
1.7
H
4
4
1.5
O 42
2.6
1
N, S traces
* unsaturated
* high O but insoluble
 ether, but not acid
or phenol groups.
* dark red/brown solid
* purify by
- recrystallization (NaOH and HCl)
- dialysis against water (removes cations)
* speciate using MW cutoff dialysis.
**
C
H
O
N
S
mole
wt% mole% ratio
55
4.6
2.1
5
5
2.3
35 2.2
1
3
0.2
1
0.03
C21H23O10
C:H ~1:1  high
degree of
unsaturation
Chemosphere. 2005 Sep;60(9):1214-21. Epub 2005 Apr 1.
Long-term effect of sewage sludge application on soil humic acids.
Adani F, Tambone F.
Sewage sludges are used in
agriculture because they act as a
fertilizer. Long-term studies are
needed to evaluate the effect of
sewage sludge on soil properties by
paying particular attention to the soil
organic matter.
Soil plots were amended for 10
years with 1Mg dry matter ha(1)year(-1) of sewage sludge.
Chemical parameters such as
total organic carbon (TOC), N,
C/N ratio and CEC were
determined when this period
ended. Moreover, TOC was
fractionated into humified and
non-humified fractions. Humic
acids (HA) were isolated and
studied by elemental analysis,
DRIFT, (1)H NMR and CPMAS
13C NMR spectroscopies.
At the end of the tests, compared to the control soil, the sludgeamended soil did not exhibit change in total organic C and
related humified fractions.
However, the HA composition of the soil treated with sludge had
developed an HA composition closer to that of the HA-sludge as
a result of the enrichment of recalcitrant fractions contained in
the sludge.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/16018891 ….. Diunduh 28/4/2012
KARAKTERISASI SUBSTANSI HUMIK
b) Acidity: The phenolic, R-OH and R-COOH functional groups give
acidity but the many functional groups in many chemical environments
prohibit the definition of an “acid dissociation constant” - many pKas but
they will be experimentally indistinguishable.
Therefore titrate with standard base over a defined pH range operationally defined. FA ~ 5meq/g.
For HA dissolve in excess base and back titrate with standard acid.
Al(OH)3 + OH- → Al(OH)4Gibbsite dissolution under Bayer conditions (3.5M NaOH, 140C)
Waste Manag Res. 2008 Feb;26(1):47-60.
Green house gas emissions from composting and mechanical biological
treatment.
Amlinger F, Peyr S, Cuhls C.
In order to carry out life-cycle assessments as a
basis for far-reaching decisions about
environmentally sustainable waste treatment, it is
important that the input data be reliable and
sound. A comparison of the potential greenhouse
gas (GHG) emissions associated with each solid
waste treatment option is essential.
This paper addresses GHG
emissions from controlled
composting processes. Some
important methodological
prerequisites for proper
measurement and data
interpretation are described, and a
common scale and dimension of
emission data are proposed so
that data from different studies
can be compared.
A range of emission factors
associated with home composting,
open windrow composting,
encapsulated composting systems
with waste air treatment and
mechanical biological waste
treatment (MBT) are presented
from our own investigations as
well as from the literature.
The composition of source materials along with process management issues such as
aeration, mechanical agitation, moisture control and temperature regime are the most
important factors controlling methane (CH4), nitrous oxide (N2O) and ammoniac (NH3)
emissions. If ammoniac is not stripped during the initial rotting phase or eliminated by
acid scrubber systems, biofiltration of waste air provides only limited GHG mitigation,
since additional N2O may be synthesized during the oxidation of NH3, and only a small
amount of CH4 degradation occurs in the biofilter. It is estimated that composting
contributes very little to national GHG inventories generating only 0.01-0.06% of global
emissions. This analysis does not include emissions from preceding or post-treatment
activities (such as collection, transport, energy consumption during processing and land
spreading), so that for a full emissions account, emissions from these activities would
need to be added to an analysis.
Sumber:
http://www.ncbi.nlm.nih.gov/pubmed/18338701 ….. Diunduh 28/4/2012
KARAKTERISASI SUBSTANSI HUMIK
c) Vibrational
spectroscopy
(CC)aromatic
stretching
OH
stretch
(C-H)aliphatic
stretching
(C=O)acyl
stretchin
g
Kingston Harbour
sediment Humic
Acid
C-O stretching
& C-OH
bending
Kingston Harbour
sediment Fulvic Acid
Bioresour Technol. 2009 Nov;100(22):5454-60. Epub 2009 Jan 20.
Utilisation of manure composts by high-value crops: safety and environmental
challenges.
Moral R, Paredes C, Bustamante MA, Marhuenda-Egea F, Bernal MP.
The intensification in livestock
production has increased the need of
efficient treatments of waste streams
especially to preserve as much as
possible, the nutrients into the soilplant system.
Composting is a cheap,
efficient and sustainable
treatment for solid wastes that
is always included in any
manure treatment scenario.
In this paper, an overview about the environmental and safety
challenges of composting of manures is made considering the
compost quality requirements established by the main demanding
sectors.
Co-composting and additive strategies are presented as feasible
options for the improvement of compost quality.
For quality evaluation of manure compost, the use of both classical
and innovative instrumental techniques could increase our
knowledge about added properties in compost, especially those
related to organic matter stability.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/19157868 ….. Diunduh 28/4/2012
KARAKTERISASI SUBSTANSI HUMIK
d) NMR spectroscopy: (Solomons Chapter 14)
13C,
solid state or NaOH solution.
Ho = Happlied(1-) where  is a
shielding constant. The observed
field at the nucleus is shifted from the
applied field by magnetic properties of
the shielding electrons. Quote the
field at which resonance occurs
relative to a standard (usually
tetramethylsilane - TMS).
* Broad band spectra (materials not
homogeneous, solid state NMR
have complicated orientational
effects and lattice-nuclear spin
interactions).
* Chemical shifts indicate functional
groups.
* areas under peaks indicate
relative amounts of functional
groups.
Bioresour Technol. 2009 Nov;100(22):5444-53. Epub 2008 Dec 31.
Composting of animal manures and chemical criteria for compost maturity
assessment. A review.
Bernal MP, Alburquerque JA, Moral R.
New livestock production systems, based
on intensification in large farms, produce
huge amount of manures and slurries
without enough agricultural land for their
direct application as fertilisers. Composting
is increasingly considered a good way for
recycling the surplus of manure as a
stabilised and sanitised end-product for
agriculture, and much research work has
been carried out in the last decade.
However, high quality compost should be
produced to overcome the cost of
composting.
In order to provide and
review the information found
in the literature about manure
composting, the first part of
this paper explains the basic
concepts of the composting
process and how manure
characteristics can influence
its performance. Then, a
summary of those factors
such as nitrogen losses
(which directly reduce the
nutrient content), organic
matter humification and
compost maturity which
affect the quality of composts
produced by manure
composting is presented.
Special attention has been paid to the relevance of using an
adequate bulking agent for reducing N-losses and the necessity
of standardising the maturity indices due to their great
importance amongst compost quality criteria.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/19119002 ….. Diunduh 28/4/2012
KOMPOS DAN PENGOMPOSAN
“Kompos” merupakan hasil dekomposisi bahan organik yang dapat
dipercepat secara artifisial oleh populasi mikroba dalam kondisi lingkungan
yang hangat, lembab, dan aerobik atau anaerobik.
“Pengomposan” adalah proses dimana bahan organik mengalami
dekomposisi secara biologis, khususnya oleh mikroba-mikroba yang
memanfaatkan bahan organik tersebut sebagai sumber energy, sumber karbon
dan sumber makanannya.
“Membuat kompos” berarti mengatur
dan mengontrol proses dekomposisi
bahan organic tersebut agar
kompos dapat terbentuk lebih cepat.
Proses ini meliputi membuat
campuran bahan organic yang
seimbang komposisinya, pemberian
air yang cukup, mengaturan aerasi,
dan penambahan aktivator
pengomposan.
Kompos dapat diperkaya dengan unsur hara esensial makro dan
mikro. Kompos ini dapat digunakan sebagai pupuk di kebun, taman,
tanaman hortikultura, dan tanaman pertanian lainnya.
Kompos sangat bermanfaat untuk memperbaiki kualitas tanah, dapat
berfungsi sebagai pembenah tanah, sebagai pupuk, sumber humus
dan asam humat, atau sebagai pestisida alami bagi tanah.
Dalam ekosistem tanah, kompos bermanfaat untuk mengendalikan
erosi, reklamasi lahan, dan lainnya.
KOMPOS DAN PENGOMPOSAN
JENIS-JENIS KOMPOS
1.
2.
3.
4.
Kompos cacing (vermicompost), yaitu kompos yang terbuat dari
bahan organik yang dicerna oleh cacing. Bahan yang menjadi pupuk
adalah kotoran cacing tersebut.
Kompos bagase, yaitu pupuk yang terbuat dari ampas tebu sisa
penggilingan tebu di pabrik gula.
Kompos bokashi.
KOMPOS
Empat fungsi penting kompos, yaitu:
1.
2.
3.
4.
Fungsi nutrisi, nutrisi yang disimpan diubah menjadi bahan organik,
jaringan mikroorganisme, produk sisanya, dan humus. Kompos
adalah pupuk yang lambat tersedia (slow release), hara yang
dihasilkan tergantung pada bahan dasar dan metode pengomposan
yang digunakan.
Meningkatkan struktur tanah, yaitu melalui peningkatan persentase
bahan organik yang meningkatkan stuktur tanah.
Meningkatkan populasi dan aktivitas organisme tanah. Kompos
juga meningkatkan kemampuan mengikat air dan agregat tanah,
meningkatkan infiltrasi, menghalangi terjadinya erosi dan
menunjang penyebaran dan penetrasi akar tanaman.
Memperkuat daya tahan tanaman terhadap hama dan penyakit.
Berbagai penelitian telah menunjukkan bahwa tanaman yang diberi
pupuk kompos lebih tahan terhadap hama dibandingkan tanaman
yang tidak diberi kompos maupun yang tidak dipupuk.
. Penggunaan kompos sangat baik karena dapat memberikan manfaat baik
bagi tanah maupun tanaman. Kompos dapat menggemburkan tanah,
memperbaiki struktur dan porositas tanah, serta komposisi mikroorganisme
tanah, meningkatkan daya ikat tanah terhadap air, menyimpan air tanah
lebih lama, dan mencegah lapisan kering pada tanah. Kompos juga
menyediakan unsur hara mikro bagi tanaman, memudahkan pertumbuhan
akar tanaman, mencegah beberapa penyakit akar, dan dapat menghemat
pemakaian pupuk kimia dan atau pupuk buatan, sehingga dapat
meningkatkan efisiensi pemakaian pupuk kimia.
KOMPOS DAN PENGOMPOSAN
Manfaat Ekonomi :
1.
2.
3.
Menghemat biaya untuk transportasi dan penimbunan
limbah
Mengurangi volume/ukuran limbah
Memiliki nilai jual yang lebih tinggi dari pada bahan asalnya
Mafaat Lingkungan :
1.
2.
3.
Mengurangi polusi udara karena
pembakaran limbah dan pelepasan
gas metana dari sampah organik yang
membusuk akibat bakteri metanogen
di tempat pembuangan sampah
Mengurangi kebutuhan lahan untuk
penimbunan sampah
……………
Manfaat KOMPOS bagi tanah dan tanaman:
1.
2.
3.
4.
5.
6.
7.
8.
Meningkatkan kesuburan tanah
Memperbaiki struktur dan karakteristik tanah
Meningkatkan kapasitas penyerapan air oleh tanah
Meningkatkan aktivitas mikroba tanah
Meningkatkan kualitas hasil panen (rasa, nilai gizi, dan jumlah panen)
Menyediakan hormon dan vitamin bagi tanaman
Menekan pertumbuhan/serangan penyakit tanaman
Meningkatkan retensi/ketersediaan hara di dalam tanah
KOMPOS DAN PENGOMPOSAN
Dekomposisi Bahan Organik
Proses dekomposisi bahan organic menghasilkan beragam hasil, bauik yang
berupa hasil antara maupun hasil akhir. Hasil akhir dari proses ini disebut
HUMUS, berwarna gelap dan stabil.
Humus dapat didefinisikan sebagai kompleks ligno-protein atau kompleks
asam amino-lignin yang mengandung sekitar 45% senyawa lignin, 35% asamamino, 11% karbohydrates, 4% cellulose, 7% hemicellulose, 3% lemak, lilin
dan resin; dan 6% senyawa lainnya termasuk zat pemicu pertumbuhan dan
inhibitors.
Sumber: http://www.microbiologyprocedure.com/organic-matterdecomposition/humus.html) ….. Diunduh 20/4/2012
KOMPOS DAN PENGOMPOSAN
. Mikro-organisme dalam Pengomposan
Dengan pencampuran yang tepat antara air, oksigen, carbon, dan nitrogen,
mikro-organisme dapat melakukan dekomposisi bahan organik menghasilkan
KOMPOS. Ada banyak jenis mikroba yang aktif dalam kompos, yang paling
lazim adalah:
1. Bacteria- Jenis mikroba yang ditemukan dalam kompos.
2. Actinomycetes- Diperlukan untuk menghancurkan produk-produk kertas,
seperti newspaper, bark, dsb.
3. Fungi- Molds dan yeast, membantu menghancurkan materisl yang tidak
dapat dihancurkan oleh bakteri, seperti lignin dalam bahan-bahan berkayu.
4. Protozoa- Membantu mengkonsumsi bakteri, fungi dan partikulat organik
mikro.
5. Rotifers- Rotifers membantu mengendalikan populasi bakteri dan small
protozoans.
. Organisme pengomposan ini memerlukan empat imput penting
secara simultan untuk dapat bekerja secara efektif:
1.
2.
3.
4.
Carbon — untuk energy; oksidasi mikrobiologis karbon menghasilkan
panas.
Material kaya karbon cenderung coklat dan kering.
Nitrogen — untuk menumbuhkan dan reproduksi organisme untuk
mengoksidasi karbon.
Material kaya nitrogen cenderung hijau (seperti buah dan
sayuran) dan basah.
Oxygen — untuk oksidasi karbon dan proses dekomposisi.
Water — dalam jumlah yang tepat untuk mempertahankan aktivitas
tanpa menimbulkan kondisi anaerobik.
KOMPOS DAN PENGOMPOSAN
Ratio yang tepat dari material-material di atas akan mensuplai bakteri
dengan hara yang tepat sehingga ia dapat bekerja secara efektif dan
akan memanaskan timbunan bahan organik dalam pengomposan.
Dalam proses ini akan dilepaskan banyak air sebgaai bentuk uap, dan
oksigen akan cepat berkurang; sehingga timbunan bahan organik
harus sering diaduk-aduk.
Semakin panas timbunan bahan organik, diperlukan penambahan
udara dan air yang semakin sering.; keseimbangan udara/air menjadi
sangat penting untuk mempertahankan suhu tinggi hingga bahan
organik terdekomposisi.
Pada saat yang sama, terlalu banyak udara atau air juga dapat
emenghambat proses dekomposisi, karena terlalu banyak carbon (atau
terlalu sedikit nitorgen).
Proses pengomposan paling efisien terjadi kalau bahan
organik mempunyai ratio C/N = 30 / 1.
Semua biomasa tumbuhan dan hewan mengandung N dan
C , tetapi jumlahnya sangat beragam, dengan karakteristik
yang berbeda-beda.
Biomasa legume segar mempunyai C/N ratio sekitar 15 : 1
dan daun-daun gugudran kering mempunyai C/N ratio
sekitar 50 : 1 tergantung spesiesnya.
Kalau kedua bahan ini dicampur akan dapat diperioleh
kisaran C/N ratio yang ideal.
MINERALISASI DAN HUMIFIKASI
The most important function of soil microorganism is the decomposition of
various kinds of organic matter present in the soil. Virtually all types of organic
matters eventually find their way to the soil or to the sea. The soil organic
matter chiefly consists of residues of dead plant and animals, and the or to the
sea. The soil organic matter chiefly consists of residues of dead plant and
animals, and the excretory products of the living beings.
These organic constituents need to be converted into simple inorganic forms
(minerals) to make them available to the autotrophic organisms. This
conversion of organic matter into simple inorganic forms is called
mineralization.
A conceptual model of nitrogen cycling in ornamental landscapes.
Decomposing organic matter releases organic nitrogen that is mineralized
into forms available for plant and microbial uptake. Fertilization supplements
the available nitrogen pool. Nitrogen acquired by microbial biomass is
immobilized and thus is unavailable for plant uptake. As microbes die and
are themselves decomposed, nitrogen is returned to the available pool.
(Sumber: http://ohioline.osu.edu/sc186/sc186_14b.html)
Mineralisasi Bahan Organik oleh Mikroba , berakhir
pada Humifikasi
Proses dekomposisi oksidatif mengubah bahan organic segar menjadi
senyawa-senyawa anorganik yang lebih sederhana (proses mineralisasi)
yang tersedia bagi pertumbuihan tanaman; dan residunya diubah menjadi
humus sebagai hasil dari proses ‘humification’; proses mineralization dan
humification berlangsung secara sinergis-bersamaan.
Sumber: http:/ / www.studentsguide.in/microbiology/soil-microbiology/decomposition-oforganic-matter-soil-by-mineralization-and-humification.html
….. Diunduh 20/4/2012
DEKOMPOSISI BAHAN ORGANIK DALAM
TANAH
. The mineralization is rendered mainly through decomposition of organic
matter by soil microorganism, mainly fungi and bacteria. It is estimated that
90% of the mineralization of organic matter is the result of the metabolism of all
other organisms, as well as the combustion of fuel and other materials.
. Proses dekomposisi bahan organic (segar) berlangsung cepat atau lambat
tergantung padakomopisi kimiawi dari bahan organic tersebut. Proses
dekomposisi bersifat kontinyu, tetapi berbagai komponen terdegradasi
dengan laju yang berbeda-beda.(sumber:
http://wvlc.uwaterloo.ca/biology447/modules/module8/ soil/chap2d.htm).
PROSES KIMIAWI DEKOMPOSISI BO
Keseimbangan Hara - C/N Ratio
Nutrient balance is very much dependent on the type of feed materials being
processed. Carbon provides the preliminary energy source and nitrogen
quantity determines the microbial population growth. Hence, maintaining the
correct C:N ratio is important to obtain good quality compost. Bacteria,
actinomycetes, and fungi require carbon and nitrogen for growth. These
microbes use 30 parts of carbon to 1 part of nitrogen.
Composting is usually successful when the mixture of organic materials
consists of 20-40 parts of carbon to 1 part of nitrogen. However, as the ratio
exceeds 30, the rate of composting decreases. Further, as the ratio decreases
below 25, excess nitrogen is converted to ammonia. This is released into the
atmosphere and results in undesirable odor
Proses dekomposisi bahan organic dipengaruhi
oleh adanya C dan N. C:N ratio mencerminkan
proporsi relative dari kedua unur ini. Suatu
material, misalnya, mempunyai karbon 25 kali
lebih banyak daripada nitrogen, maka disebut ia
mempunyai C:N ratio sebesar 25:1, atau C:N
ratio 25.
Organism yang mendekomposisi bahan organic menggunakan carbon
sebagai sumber energi dan nitrogen untuk membangun struktur sel-selnya.
Mereka memerlukan lebih banyak C daripada N. Kalau terlalu banyak C,
dekomposisi melambat ketika nitrogen sudah digunakan semua dan
sebagian organisms mati.
Organisme lainnya membentuk material sel-selnya yang baru
menggunakan N simpanannya. Dalam prosesnya lebih banyak karbon
dibakar. Sehingga jumlah karbon lebih banyak berkurang, sedangkan
nitrogen didaur-ulang. Akan tetapi proses dekomposisi berlangsung terus,
ketika nilai C/N ratio masih lebih besar dari 30.
C/N RATIO BAHAN ORGANIK
Nilai C:N ratio 20, dimana C dan N merupakan jumlah yang tersedia,
merupakan batas atas bagi kompos dimana tidak ada bahaya
perampokan nitrogen tanah.
Kalau banyak karbon berbentuk lignin atau material resisten lainnya,
maka nilai actual C:N ratio lebih besar dari 20. Nilai C:N ratio
menjadi factor kritis dalam pengomposan untuk mencegah
perampokan nitrogen tanah dan konservasi maximum-nitrogen
dalam kompos.
. Sumber: http: // whatcom.wsu.edu/ag/compost/fundamentals/
needs_carbon_nitrogen.htm
PERUBAHAN RATIO C/N
During bio-conversion of the materials, concentration of carbon will be
reduced while that of nitrogen will be increased, resulting in the reduction of
C:N ratio at the end of the composting process. The reduction can be
attributed to the loss in total dry mass due to losses of C as CO2
Ammonium-N (NH4-N) and nitrate-N (NO3-N) will also undergo some
changes. NH3 levels were increasing in the initial stages but declining
towards the end (Liao et al. 1995). In several instances, NO3 concentrations
were less during the initial phases but gradually increased towards the end
and, in some instances, remained unchanged.
Maintaining NH3 concentration is important to avoid excess nitrogen losses
and production of bad odor. Maintaining C:N ratio after composting is also
important to determine the value of finished compost as soil amendment for
crops. The final C:N ratio of 15 to 20 will be expected and the value of more
than 20 might have a negative impact and will damage the crop and seed
germination. The value of 10 has been suggested as ideal.
Hubungan antara C:N ratio bahan organic dengan laju mineralisasi N.
(sumber: http://www.new.dpi.vic.gov.au/agriculture/farming-management/organicfarming/organic-viticulture/soil-management)
Fosfor (P)
Levels of P along with N and K will be important to determine the
quality of compost, as P is also one of the essential nutrients for
plant growth. A C:P ratio of 100 to 200 is desirable (Howe and Coker,
1992). Phosphorus is not lost by volatilization or lixiviation during the
composting process, but P concentration might increase as
composting proceeds.
. Soil phosphorus forms and plant uptake.
(Sumber:
http://extension.missouri.edu/publications/DisplayPub.aspx?P=G9180)
MINERALISASI SENYAWA P ORGANIK
Bentuk P dalam tanah yang tersedia bagi tanaman adalah anion
orthophosphate. Untuk ketersediaan jangka panjang, senyawa organic Po
dapat dirombak untuk melepaskan orthophosphate. Senyawa-senyawa
compounds ini berasal dari microorganisms dan limbah tanaman dan ternak,
merupakan bagian dari materiak humik yang stabil dalam tanah. Agar supaya
P dari sumber organic ini dapat tersedia, ia perlu dihidrolisis dan dimineralisasikan oleh mikroba, yang merupakan proses penting untuk
melepaskan ion orthophosphate yang tersedia bagi tanaman dan menjaga
siklus P dalam ekosistem. Melalui proses mineralisasi, senyawa-senyawa Po
merupakan sumber P yang penting bagi tanaman dan mikroba tanah.
. Pelepasan fosfat dari senyawa P organic. (Sumber: http://
www.scielo.cl/scielo.php?script=sci_arttext&pid=S071827912006000200006&lng=en&nrm=iso&ignore=.htm)
SULFUR (S) (BELERANG)
Adanya S dalam jumlah yang cukup banyak dapat memicu pembentukan senyawa
volatile yang berbau menyengat.
Sumber utama S adalah dua asam aminio, yaitu cysteine dan methionine. Pada
kondisi aerasi yang bagus, sulfides dioksidasi menjadi sulfates; tetapi pada kondisi
anaerobic, mereka diubah menjadi sulfide organic yang volatuile atau menjadi H2S,
menimbulkan bau busuk. Beberapa senyawa seperti carbon disulfide, carbonyl
sulfide, methyl mercaptum, diethyl sulfide, dimethyl sulfide, dan dimethyl disulfide
juga dapat menimbulkan bau busuk.
. (Sumber: http://www.scripps.edu/chem/wong/)
Belerang atau sulfur adalah unsur kimia dalam tabel periodik yang memiliki
lambang S dan nomor atom 16.
Bentuknya adalah non-metal yang tak berasa. Belerang, dalam bentuk aslinya,
adalah sebuah zat padat kristalin kuning. Di alam, belerang dapat ditemukan
sebagai unsur murni atau sebagai mineral- mineral sulfide dan sulfate. Ia
adalah unsur penting untuk kehidupan dan ditemukan dalam dua asam amino.
Penggunaan komersilnya terutama dalam fertilizer namun juga dalam bubuk
mesiu, korek api, insektisida dan fungisida.
Sumber: http://id.wikipedia.org/wiki/Sulfur ….. Diunduh 20/4/2012
DEKOMPOSISI BO:
EFEK SUHU DAN KELEMBABAN
Temperature and moisture may influence the size and composition of the
mineralizable fraction, which in itself is not yet well defined. If advances are to
be made in understanding organic S turnover, improvements in
characterization of organic S are vital. The separation of organic S into the two
large, chemically 'fuzzy' pools of organic sulphate and carbon-bonded S is no
longer sufficient for interpretation of the sophisticated incubation and tracer
experiments now utilized. Attempts must be made to distinguish analytically the
organic S pools of definite chemical and biological function. The recent
development of the 'microbial biomass S pool' is a good step in this direction.
. Mineralisasi belerang – sulfat secara kumulatif darui bahan organic jerami
wheat-fallow dan perennial forage (alfalfa), menyatakan pelepasan S dan
perubahan fraksi dapat-lapuk yang diprediksi dengan model kinetik.
(Sumber: http://www.icsu-scope.org/downloadpubs/scope48/chapter10.html)
PROSES FISIKA DALAM PENGKOMPOSAN
Kadar Air
Moisture in compost comes from either the initial feedstock or the metabolic
water produced by microbial action (0.6-0.8 g/g), but, during aerobic
composting, 1 g of organic matter releases about 25 kJ of heat energy, which is
enough to vaporize 10.2 g of water (Finstein et al. 1986). This will be further
coupled with losses due to aeration (Naylor 1996), resulting in water loss
during composting. Hence, moisture is an important factor to be controlled
during composting as it influences the structural and thermal properties of the
material, as well as the rate of biodegradation and metabolic process of the
microbes.
The moisture content of compost should be 60% after organic wastes have
been mixed. Depending on the components of the mixture, initial moisture
content can range from 55%-70%. However, if this exceeds 60%, the structural
strength of the compost deteriorates, oxygen movement is inhibited, and the
process tends to be anaerobic. Low C:N ratio materials (e.g., meat wastes)
putrefy when anaerobic, while high ratio materials ferment. Both these
processes produce odor, leach nutrients, increase pathogens, and block air
passages in the pile, hence they must be avoided.
As the moisture content decreases below 50%, the rate of decomposition
decreases rapidly. Excessive moisture in the compost will prevent O2
diffusion to the organisms. Reduction in the moisture content below 30%35% must be avoided since it causes a marked reduction in the
microbiological activity.
Moisture can be controlled either directly by adding water or indirectly by
changing the operating temperature or the aeration regime. Feedstock with
different moisture-holding capacities can be blended to achieve an ideal
moisture content.
Sumber:
….. Diunduh 20/4/2012
PROSES FISIKA DALAM PENGKOMPOSAN
Oksigen dan Aerasi
Aeration is a key element in composting, especially in aerobic composting, as
a large amount of oxygen is consumed during initial stages. Aeration provides
oxygen to the aerobic organisms necessary for composting. Proper aeration is
needed to control the environment required for biological processes to thrive
with optimum efficiency.
Oxygen is not only necessary for aerobic metabolism of microorganisms, but
also for oxidizing various organic molecules present in the composting mass. It
also has the important function of controlling temperature as well as of
removing excess moisture and gases.
If the oxygen supply is limited, the composting process might turn anaerobic,
which is a much slower and odorous process. A minimum oxygen
concentration of 5% is necessary to avoid an anaerobic situation. Turning the
pile regularly or by mechanical agitation will ensure sufficient oxygen supply.
.Aerasi Pada Pengomposan
Pengomposan yang cepat dapat terjadi
dalam kondisi yang cukup
oksigen(aerob). Aerasi secara alami
akan terjadi pada saat terjadi
peningkatan suhu yang menyebabkan
udara hangat keluar dan udara yang
lebih dingin masuk ke dalam tumpukan
kompos.
Aerasi ditentukan oleh porositas dan
kandungan air bahan(kelembapan).
Apabila aerasi terhambat, maka akan
terjadi proses anaerob yang akan
menghasilkan bau yang tidak sedap.
Aerasi dapat ditingkatkan dengan
melakukan pembalikan atau
mengalirkan udara di dalam tumpukan
kompos.
Skema Proses Pengomposan Aerobik
Sumber: http://id.wikipedia.org/wiki/Kompos ….. Diunduh 20/4/2012
PROSES FISIKA DALAM PENGKOMPOSAN
Ukuran Partikel Bahan Kompos
Decomposition and microbial activity will be rapid near the surfaces as oxygen diffusion is
very high. Small particles have more surface area and can degrade more quickly. Haug
(1993) suggested that, for particles larger than 1 mm, oxygen diffusion would limit in the
central part of the particles, thus the interior parts of the larger particles will be anaerobic
with a slower rate of decomposition. Particle size also affects moisture retention as well as
free air space and porosity of the compost mixture.
Smaller particle size results in reduced air space and less porosity. Aerobic decomposition
increases with smaller particle size; however, smaller particle size reduces the effectiveness
of the oxygen supply. By turning regularly, this problem can be solved.
The preferable size is 3 mm - 50 mm diameter.
Compaction can also influence the free air space. By employing grinding and sieving
equipment, such problems can be avoided. At the end of the process, the bulk density of the
compost would be expected to increase due to breakdown in the particle size of the
material, resulting in more compact compost. But in some composting systems, where water
evaporation and water loss are high, the bulk density might decrease as the materials will be
dried during the composting period.
Pile size and porosity of the material
The size of the pile is of great significance and finds mention in the
sections on passive composting of manure piles and turned wind-rows .
Where the pile or wind-row is too large, anaerobic zones occur near its
centre, which slows the process in these zones. On the other hand, piles
or wind-rows that are too small lose heat quickly and may not achieve a
temperature high enough to evaporate moisture and kill pathogens and
weed seeds.
The optimal size of the piles and wind-rows should also consider such
parameters as the physical property (porosity) of the materials and the
way of forming the pile. While more porous materials allow bigger piles,
heavy weights should not be put on top and materials should be kept as
loose as possible. Climate is also a factor. With a view to minimizing heat
loss, larger piles are suitable for cold weather. However, in a warmer
climate, the same piles may overheat and in some extreme cases (75 °C
and above) catch fire.
Sumber: http://www.fao.org/docrep/007/y5104e/y5104e05.htm#TopOfPage ….. Diunduh 26/4/2012
PROSES BIOLOGIS DALAM
PENGKOMPOSAN
Pathogens selama Pengomposan
1.
2.
3.
4.
5.
In addition to the already discussed microbes, there will be many human,
animal, and plant pathogens. It is not only the heat of the compost that
destroys all these pathogens; it is a combination of factors including:
competition for food from compost microorganisms;
inhibition and antagonism by compost microorganisms;
consumption by compost microorganisms;
biological heat generated by compost microorganisms; and
antibiotics produced by compost microorganisms.
There is no doubt that the heat produced by thermophilic
bacteria kills pathogenic microorganisms, viruses, bacteria,
protozoa, worms, and eggs that may inhabit humans.
A temperature of 50°C (122°F), if maintained for 24 h, is
sufficient to kill all the pathogens, according to some sources. A
lower temperature will take longer to kill the pathogens.
A temperature of 46°C (115°F) may take nearly a week to kill the
pathogens completely; a higher temperature may take only
minutes. What we have yet to determine is how low those
temperatures can be and still achieve satisfactory pathogen
elimination.
PROSES BIOLOGIS DALAM
PENGKOMPOSAN
. The microbial biodiversity of compost is also important because it aids in the
breakdown of the organic material. For example, in high-temperature compost
(80°C), only about 10% of sewage sludge solids could be decomposed in three
weeks, whereas at 50°-60°C, 40% of the sludge solids were decomposed in
only seven days. The lower temperatures apparently allowed for a richer
diversity of living things, which, in turn, had a greater effect on the degradation
of the organic matter.
Even if every speck of the composting material is not subjected to the high
internal temperatures of the compost pile, the process of thermophilic
composting nevertheless contributes immensely to the creation of a sanitary
organic material. Or, in the words of one group of composting professionals:
"The high temperatures achieved during composting, assisted by the
competition and antagonism among the microorganisms (i.e., biodiversity),
considerably reduce the number of plant and animal pathogens. While some
resistant pathogenic organisms may survive and others may persist in cooler
sections of the pile, the disease risk is, nevertheless, greatly reduced."
Temperature
The process of composting involves two temperature ranges: mesophilic
and thermophilic.
While the ideal temperature for the initial composting stage is 20-45 °C, at
subsequent stages with the thermophilic organisms taking over, a
temperature range of 50-70 °C may be ideal.
High temperatures characterize the aerobic composting process and
serve as signs of vigorous microbial activities.
Pathogens are normally destroyed at 55 °C and above, while the critical
point for elimination of weed seeds is 62 °C. Turnings and aeration can be
used to regulate temperature.
Sumber: http://www.fao.org/docrep/007/y5104e/y5104e05.htm#TopOfPage ….. Diunduh 20/4/2012
PERUBAHAN KIMIAWI DALAM
PENGKOMPOSAN
. During composting, around 50% of the organic matter will be fully mineralized,
producing CO2 and water. Protein, cellulose, and hemicelluloses are easily
degradable. Many of these compounds produce organic residues, referred to
as humic matter. A great deal of work has been recently conducted on humic
matter from various sources. The amount of humic acid increases during the
process. Increase in aromatic structures, phenolic structures, and carboxylic
structures was also evidenced, whereas decrease in O-alkyl structures,
polysaccharides, and amino acids was recorded with no changes in alkyl
structures and carbohydrates (Chefetz et al. 1998).
. Senyawa Intermediate (antara) yang bersifat Toksik
Many phytotoxic chemicals will also be produced during composting
that might significantly impact on germination, plant growth, and also
plant pathogens.
In many instances, composting can also be a source of zenobiotic and
hazardous volatile organic compounds. Recently, more than 20 different
types of volatile organic compounds and their intermediates were
recovered from the municipal solid waste composting facility (Komilis et
al. 2004).
The major phytotoxic compounds include either phenolic compounds or
short chain fatty acids (Young and Chou 2003).
Some of the phenolics are vanillic, trans-p-coumaric, cis-p-coumaric, phydroxybenzoic, ferulic, and o-hydroxyphenylacetic acids; short chain
fatty acids include acetic acid, propionic acid, and butyric acid. The
amount of these compounds varies with the composting method and
feedstock.
Sumber:
….. Diunduh 20/4/2012
PERUBAHAN KIMIAWI DALAM
PENGKOMPOSAN
. Kontrol Proses
Composting, being a microbial process, can be proceeded with a desired
efficiency when the environmental requirements for decomposition are met at
their optimal levels. To attain this, it is necessary to control the treat process.
The important control parameters such as pH, humidity, and C:N ratio can
serve as indicators for expected process failure.
It is necessary to monitor the pH and maintain it between 6 and 7.5, which is
an optimum range. It is well understood that during the process, this parameter
undergoes considerable change from an initial pH of 5-6 due to the formation
of carbon dioxide and organic acids.
As the process progresses, the value will rise to 8-8.5, which is due to the
decomposition of proteins and elimination of carbon dioxide.
In a practical operation, very little evidence exists that pH should be artificially
adjusted.
The microorganisms that produce the acids can also utilize them as
food after higher oxygen concentrations are established.
This typically occurs within a few days after the most readily
biodegradable substances have been destroyed. The net effect is that
the pH begins to rise after a few days.
The rise continues until a level of 7.5-9.0 is reached, and the mass
becomes alkaline. Attempts to control pH with sulphur compounds are
often difficult to justify because of the cost involved.
Sumber:
….. Diunduh 20/4/2012
PERUBAHAN KIMIAWI DALAM
PENGKOMPOSAN
Kontrol Proses
As discussed earlier, the temperature change during the process has a
profound influence on the efficiency of the process. As microorganisms
decompose (oxidize) organic matter, heat is generated and the temperature of
the compost is raised a few degrees as a result. The temperature is increased
to 60o-65oC in the second phase and the thermophilic digestion takes over.
Thermophilic treatment has advantage because of the increased organic
removal efficiency, improved solid-liquid separation, and destruction of
pathogens. Above 60oC, the thermophilic fungus flora dies while continuing the
actinomycetes' activities. The process stops when readily biodegradable
material is fully consumed.
The temperature then gradually decreases, which activates the reinvasion of
the thermophilic fungus flora, which attacks the cellulose materials. On the
completion of the digestion, the temperature returns to the ambient.
The increase in the temperature favors saprophytic activities that
cause the transformation of the material in composting.
Most composting should include temperature in the thermophilic
range.
At these temperatures, the rate of organic matter decomposition is
maximum, and weed seeds and most pathogenic microbes cannot
survive. It is also very important to mix the composting substances
so as to ensure that all parts are exposed to high temperatures.
Sumber:
….. Diunduh 20/4/2012
PERUBAHAN KIMIAWI DALAM
PENGKOMPOSAN
Mineralisasi
The end products of any composting process are water, organic and inorganic
matter that can be used as soil amendment to supply essential nutrients to the
plants, in addition to the buffering action and to increase water-holding
capacity.
During the composting process, the ash or inorganic component increases due
to the loss of organic fraction or volatile solids as CO2. Values of volatile solids
present in feedstock are between 65% and 99%. About one-third (20%) of the
organic material is decomposed into water and CO2, but this will be dependent
on the feedstock, influenced by aeration, temperature control, and nutrient
levels.
In biology, mineralization refers to the process where an organic substance
is converted to an inorganic substance. This may also be a normal biological
process which takes place during the life of an organism such as the
formation of bone tissue or egg shells, largely with calcium.
Mineralization in soil science is when the chemical compounds in
organic matter decompose or are oxidized into plant-accessible
forms. Mineralization is the opposite of immobilization.
Chemical decomposition, analysis or breakdown is the separation of a chemical
compound into elements or simpler compounds. It is sometimes defined as the exact
opposite of a chemical synthesis. Chemical decomposition is often an undesired chemical
reaction. The stability that a chemical compound ordinarily has is eventually limited when
exposed to extreme environmental conditions like heat, radiation, humidity or the acidity of a
solvent. The details of decomposition processes are generally not well defined, as a
molecule may break up into a host of smaller fragments. Chemical decomposition is
exploited in several analytical techniques, notably mass spectrometry, traditional gravimetric
analysis, and thermogravimetric analysis.
A broader definition of the term decomposition also includes the breakdown of one phase
into two or more phases.
There are three broad types of decomposition reactions: thermal, electrolytic and catalytic
(SUMBER: http://en.wikipedia.org/wiki/Chemical_decomposition)
Sumber:
http://en.wikipedia.org/wiki/Mineralization_%28biology%29….. Diunduh 20/4/2012
DEKOMPOSISI KIMIAWI
Formula Reaksi Kimia
Reaksi umum untuk dekomposisi kimiawi adalah:
AB → A + B
Contoh yang spesifik adalah elektrolisis air menjadi gas hidrogen dan gas
oksigen :
2 H2O(I) → 2 H2 + O2
An example of spontaneous decomposition is that of hydrogen peroxide,
which will slowly decompose into water and oxygen:
2 H2O2 → 2 H2O + O2
Carbonates will decompose when heated, a notable exception being that of
carbonic acid, H2CO3.
Carbonic acid, the "fizz" in sodas, pop cans and other carbonated beverages,
will decompose over time (spontaneously) into carbon dioxide and water
H2CO3 → H2O + CO2
Other carbonates will decompose when heated producing the corresponding
metal oxide and carbon dioxide. In the following equation M represents a
metal:
MCO3 → MO + CO2
A specific example of this involving calcium carbonate:
CaCO3 → CaO + CO2
Metal chlorates also decompose when heated. A metal chloride and oxygen
gas are the products.
2 MClO3 → 2 MCl + 3 O2
A common decomposition of a chlorate to evolve oxygen utilizes potassium
chlorate as follows:
2 KClO3 → 2 KCl + 3 O2
Sumber:
http://en.wikipedia.org/wiki/Chemical_decomposition….. Diunduh 22/4/2012
DEKOMPOSISI THERMAL
Thermal decomposition, or thermolysis, is a chemical decomposition
caused by heat. The decomposition temperature of a substance is the
temperature at which the substance chemically decomposes.
The reaction is usually endothermic as heat is required to break chemical
bonds in the compound undergoing decomposition. If decomposition is
sufficiently exothermic, a positive feedback loop is created producing thermal
runaway and possibly an explosion.
Contoh-contoh
Calcium carbonate (Limestone or chalk) decomposes into calcium oxide and
carbon dioxide when heated:
CaCO3 → CaO + CO2
The reaction is used to make quick lime, which when hydrated becomes
slaked lime and is used a building material.
Many oxides decompose at high enough temperatures, an example being the
decomposition of mercuric oxide to give oxygen and mercury. The reaction
was used by Joseph Priestley to make the gas for the first time.
Some foods will decompose exothermically at cooking temperatures; anyone
who has overheated sugar or syrupy foods will know how long they take to
cool. Mild versions of the process will produce caramelised dishes that are
pleasant, but cannot be tasted safely before they have cooled to a comfortable
temperature. Once they start to char, such dishes commonly will continue in a
positive feedback loop; they become dangerously hot and continue to blacken
from the inside out, and smoke even well after being removed from the heat.
In films, where stuntmen have to jump through breaking windows, the window
panes are often made of sugar, which is safer than glass.
Water, when heated to well over 2000 °C, decomposes to its constituent
elements:
2 H2O → 2 H2 + O2 The compound with the highest known decomposition
temperature is carbon monoxide at ≈3870 °C (≈7000 °F).
Sumber:
http://en.wikipedia.org/wiki/Thermal_decomposition….. Diunduh 22/4/2012
DEKOMPOSISI BIOLOGIS = BIODEGRADASI
Decomposition (or rotting) is the process by which organic material is
broken down into simpler forms of matter. The process is essential for
recycling the finite matter that occupies physical space in the biome. Bodies of
living organisms begin to decompose shortly after death. Although no two
organisms decompose in the same way, they all undergo the same sequential
stages of decomposition.
The science which studies decomposition is generally referred to as
taphonomy from the Greek word taphos, meaning tomb.
One can differentiate abiotic from biotic decomposition (biodegradation).
The former means "degradation of a substance by chemical or physical
processes, eg hydrolysis). The latter one means "the metabolic breakdown of
materials into simpler components by living organisms“, typically by
microorganisms.
DEKOMPOSISI BIOMASA TUMBUHAN
Decomposition of plant matter occurs in many stages. It begins with leaching by water; the
most easily lost and soluble carbon compounds are liberated in this process.
Another early process is physical breakup or fragmentation of the plant material into smaller
bits which have greater surface area for microbial colonization and attack. In smaller dead
plants, this process is largely carried out by the soil invertebrate fauna, whereas in the larger
plants, primarily parasitic life-forms such as insects and fungi play a major breakdown role
and are not assisted by numerous detritivore species. Following this, the plant detritus
(consisting of cellulose, hemicellulose, microbial products, and lignin) undergoes chemical
alteration by microbes.
Different types of compounds decompose at different rates. This is dependent on their
chemical structure. For instance, lignin is a component of wood, which is relatively resistant
to decomposition and can in fact only be decomposed by certain fungi, such as the black-rot
fungi. Said fungi are thought to be seeking the nitrogen content of lignin rather than its
carbon content.
Lignin is one such remaining product of decomposing plants with a very complex chemical
structure causing the rate of microbial breakdown to slow. Warmth determines the speed of
plant decay, with the rate of decay increasing as heat increases, i.e. a plant in a warm
environment will decay over a shorter period of time.
In most grassland ecosystems, natural damage from fire, insects that feed on decaying
matter, termites, grazing mammals, and the physical movement of animals through the
grass are the primary agents of breakdown and nutrient cycling, while bacteria and fungi
play the main roles in further decomposition.
Sumber:
http://en.wikipedia.org/wiki/Decomposition….. Diunduh 22/4/2012
FAKTOR DEKOMPOSISI BIOLOGIS
A dead body that has been exposed to the open elements, such as water and
air, will decompose more quickly and attract much more insect activity than a
body that is buried or confined in special protective gear or artifacts. This is
due, in part, to the limited number of insects that can penetrate a coffin and
the lower temperatures under soil.
The rate and manner of decomposition in an animal body is strongly affected
by a number of factors. In roughly descending degrees of importance, they
are:
1. Temperature;
2. The availability of oxygen;
3. Prior embalming;
4. Cause of death;
5. Burial, depth of burial, and soil type;
6. Access by scavengers;
7. Trauma, including wounds and crushing blows;
8. Humidity, or wetness;
9. Rainfall;
10. Body size and weight;
11. Clothing;
12. The surface on which the body rests;
13. Foods/objects inside the specimen's digestive tract (bacon
compared to lettuce).
The speed at which decomposition occurs varies greatly. Factors such as
temperature, humidity, and the season of death all determine how fast a fresh
body will skeletonize or mummify.
A basic guide for the effect of environment on decomposition is given as
Casper's Law (or Ratio): if all other factors are equal, then, when there is free
access of air a body decomposes twice as fast than if immersed in water and
eight times faster than if buried in earth. Ultimately, the rate of bacterial
decomposition acting on the tissue will be depend upon the temperature of the
surroundings. Colder temperatures decrease the rate of decomposition while
warmer temperatures increase it.
Sumber:
http://en.wikipedia.org/wiki/Decomposition….. Diunduh 22/4/2012
PERUBAHAN KIMIAWI DALAM
PENGKOMPOSAN
Laju Respirasi (Penyerapan O2 dan Pembentukan CO2)
To ensure sufficient aeration in the compost pile, levels of oxygen consumption
and carbon dioxide formation should be monitored regularly during the entire
process. A 1:1 ratio (oxygen/ carbon dioxide) will be an indication of a good
composting process.
Usually during the process, the oxygen concentration will reflect the changes in
the CO2 evolution and temperature curves. The oxygen will decrease from its
initial value of 21% to a value of 10% over the first few days as the temperature
increases and the CO2 evolution increases, but gradually the oxygen level
increases and returns to the 21% level as the temperature reaches ambient.
The relation between CO2 evolution and oxygen consumption is called
respiratory quotient (RQ). The RQ value of a good composting process will be
about 0.9 (Atkinson et al. 1996).
Microbiology of decomposition is the study of all microorganisms
(mainly bacteria and fungi) involved in the chemical and physical
processes during which organic matter is broken down and reduced to its
original elements.
Decomposition microbiology can be divided between two fields of interest:
1. decomposition of plant materials;
2. decomposition of cadavers and carcasses.
The decomposition of plant materials is commonly studied in order to
understand the cycling of carbon within a given environment and to
understand the subsequent impacts on soil quality. Plant material
decomposition is also often referred to as composting.
The decomposition of cadavers and carcasses has become an important
field of study within forensic taphonomy.
Sumber: http://en.wikipedia.org/wiki/Microbiology_of_decomposition ….. Diunduh 20/4/2012
DEKOMPOSISI MIKROBIOLOGIS BIOMASA
TUMBUHAN
The breakdown of vegetation is highly dependent on oxygen and moisture
levels. During decomposition, microorganisms require oxygen for their
respiration.
If anaerobic conditions dominate the decomposition environment, microbial
activity will be slow and thus decomposition will be slow. Appropriate moisture
levels are required for microorganisms to proliferate and to actively decompose
organic matter.
In arid environments, bacteria and fungi dry out and are unable to take part in
decomposition. In wet environments, anaerobic conditions will develop and
decomposition can also be considerably slowed down.
Decomposing microorganisms also require the appropriate plant substrates in
order to achieve good levels of decomposition. This usually translates to
having appropriate carbon to nitrogen ratios (C:N).
The ideal composting carbon-to-nitrogen ratio is thought to be approximately
30:1. As in any microbial process, the decomposition of plant litter by
microorganisms will also be dependent on temperature. For example, leaves
on the ground will not undergo decomposition during the winter months where
snow cover occurs as temperatures are too low to sustain microbial activities
Nutrients
Micro-organisms require C, N, phosphorus (P) and potassium (K) as the
primary nutrients. Of particular importance is the C:N ratio of raw
materials. The optimal C:N ratio of raw materials is between 25:1 and 30:1
although ratios between 20:1 and 40:1 are also acceptable. Where the
ratio is higher than 40:1, the growth of micro-organisms is limited, resulting
in a longer composting time. A C:N ratio of less than 20:1 leads to
underutilization of N and the excess may be lost to the atmosphere as
ammonia or nitrous oxide, and odour can be a problem. The C:N ratio of
the final product should be between about 10:1 and 15:1.
Diunduh dari:
http://www.fao.org/docrep/007/y5104e/y5104e05.htm#TopOfPage
Sumber:
http://en.wikipedia.org/wiki/Microbiology_of_decomposition….. Diunduh 24/4/2012
RESPIRASI AEROBIK
Aerobic respiration requires oxygen in order to generate energy (ATP).
Although carbohydrates, fats, and proteins can all be processed and consumed
as reactant, it is the preferred method of pyruvate breakdown in glycolysis and
requires that pyruvate enter the mitochondrion in order to be fully oxidized by
the Krebs cycle. The product of this process is energy in the form of ATP
(adenosine triphosphate), by substrate-level phosphorylation, NADH and
FADH2
Simplified reaction:
C6H12O6 (aq) + 6 O2 (g) → 6 CO2 (g) + 6 H2O (l)
ΔG = -2880 kJ per mole of C6H12O6
The negative ΔG indicates that the reaction can occur spontaneously.
The reducing potential of NADH and FADH2 is converted to more ATP through
an electron transport chain with oxygen as the "terminal electron acceptor".
Most of the ATP produced by aerobic cellular respiration is made by oxidative
phosphorylation. This works by the energy released in the consumption of
pyruvate being used to create a chemiosmotic potential by pumping protons
across a membrane.
This potential is then used to drive ATP synthase and produce ATP from ADP
and a phosphate group. Biology textbooks often state that 38 ATP molecules
can be made per oxidised glucose molecule during cellular respiration (2 from
glycolysis, 2 from the Krebs cycle, and about 34 from the electron transport
system). However, this maximum yield is never quite reached due to losses
(leaky membranes) as well as the cost of moving pyruvate and ADP into the
mitochondrial matrix and current estimates range around 29 to 30 ATP per
glucose.
Aerobic metabolism is up to 15 times more efficient than anaerobic metabolism
(which yields 2 mol ATP per 1 mol glucose). They share the initial pathway of
glycolysis but aerobic metabolism continues with the Krebs cycle and oxidative
phosphorylation. The post glycolytic reactions take place in the mitochondria in
eukaryotic cells, and in the cytoplasm in prokaryotic cells.
Sumber:
http://en.wikipedia.org/wiki/Aerobic_metabolism….. Diunduh 24/4/2012
RESPIRASI SELULER
Cellular respiration is the set of the metabolic reactions and processes that take place in the
cells of organisms to convert biochemical energy from nutrients into adenosine triphosphate
(ATP), and then release waste products. The reactions involved in respiration are catabolic
reactions that involve the redox reaction (oxidation of one molecule and the reduction of
another). Respiration is one of the key ways a cell gains useful energy to fuel cellular activity.
Nutrients that are commonly used by animal and plant cells in respiration include sugar, amino
acids and fatty acids, and a common oxidizing agent (electron acceptor) is molecular oxygen
(O2). Bacteria and archaea can also be lithotrophs and these organisms may respire using a
broad range of inorganic molecules as electron donors and acceptors, such as sulfur, metal
ions, methane or hydrogen. Organisms that use oxygen as a final electron acceptor in
respiration are described as aerobic, while those that do not are referred to as anaerobic.
The energy released in respiration is used to synthesize ATP to store this energy. The energy
stored in ATP can then be used to drive processes requiring energy, including biosynthesis,
locomotion or transportation of molecules across cell membranes.
Cellular respiration in a typical eukaryotic cell.
Sumber:
http://en.wikipedia.org/wiki/Aerobic_metabolism ….. Diunduh 24/4/2012
GLYCOLYSIS
Glycolysis is a metabolic pathway that takes place in the cytosol of cells in all
living organisms. This pathway does not require oxygen, and can therefore
function under anaerobic conditions.
The process converts one molecule of glucose into two molecules of pyruvate
(pyruvic acid), generating energy in the form of two net molecules of ATP. Four
molecules of ATP per glucose are actually produced; however, two are
consumed as part of the preparatory phase.
The initial phosphorylation of glucose is required to destabilize the molecule for
cleavage into two pyruvate.
During the pay-off phase of glycolysis, four phosphate groups are transferred
to ADP by substrate-level phosphorylation to make four ATP, and two NADH
are produced when the pyruvate are oxidized.
The overall reaction can be expressed this way:
Glucose + 2 NAD+ + 2 Pi + 2 ADP → 2 pyruvate + 2 NADH + 2 ATP + 2 H+ + 2
H2O+energy
PYRUVATE DECARBOXYLATION
Pyruvate is oxidized to acetyl-CoA and CO2 by the pyruvate
dehydrogenase complex (PDC). The PDC contains multiple copies of three
enzymes and is located in the mitochondria of eukaryotic cells and in the
cytosol of prokaryotes.
In the conversion of pyruvate to acetyl-CoA, one molecule of NADH and
one molecule of CO2 is formed. This step is also known as the link reaction
or transition step, as it links glycolysis and the Krebs cycle.
Sumber:
http://en.wikipedia.org/wiki/Aerobic_metabolism ….. Diunduh 24/4/2012
SIKLUS ASAM SITRAT
This is also called the Krebs cycle or the tricarboxylic acid cycle. When oxygen
is present, acetyl-CoA is produced from the pyruvate molecules created from
glycolysis.
Once acetyl-CoA is formed, two processes can occur, aerobic or anaerobic
respiration. When oxygen is present, the mitochondria will undergo aerobic
respiration which leads to the Krebs cycle. However, if oxygen is not present,
fermentation of the pyruvate molecule will occur.
In the presence of oxygen, when acetyl-CoA is produced, the molecule then
enters the citric acid cycle (Krebs cycle) inside the mitochondrial matrix, and
gets oxidized to CO2 while at the same time reducing NAD to NADH. NADH
can be used by the electron transport chain to create further ATP as part of
oxidative phosphorylation. To fully oxidize the equivalent of one glucose
molecule, two acetyl-CoA must be metabolized by the Krebs cycle. Two waste
products, H2O and CO2, are created during this cycle.
The citric acid cycle is an 8-step process involving different enzymes and coenzymes. Throughout the entire cycle, acetyl-CoA(2 carbons) + Oxaloacetate(4
carbons). Citrate(6 carbons) is rearranged to a more reactive form called
Isocitrate(6 carbons).
Isocitrate(6 carbons) modifies to become α-Ketoglutarate(5 carbons), SuccinylCoA, Succinate, Fumarate, Malate, and finally, Oxaloacetate.
The net energy gain from one cycle is 3 NADH, 1 FADH2, and 1 GTP; the GTP
may subsequently be used to produce ATP. Thus, the total energy yield from
one whole glucose molecule (2 pyruvate molecules) is 6 NADH, 2 FADH2, and
2 ATP.
Sumber:
http://en.wikipedia.org/wiki/Aerobic_metabolism ….. Diunduh 24/4/2012
FOSFORILASI OKSIDATIF
In eukaryotes, oxidative phosphorylation occurs in the mitochondrial cristae. It
comprises the electron transport chain that establishes a proton gradient
(chemiosmotic potential) across the inner membrane by oxidizing the NADH
produced from the Krebs cycle.
ATP is synthesised by the ATP synthase enzyme when the chemiosmotic
gradient is used to drive the phosphorylation of ADP. The electrons are finally
transferred to exogenous oxygen and, with the addition of two protons, water is
formed.
The table below describes the reactions involved when one glucose molecule
is fully oxidized into carbon dioxide. It is assumed that all the reduced
coenzymes are oxidized by the electron transport chain and used for oxidative
phosphorylation.
coenzyme
yield
Step
ATP yield
Source of ATP
-2
Phosphorylation of glucose and fructose
6-phosphate uses two ATP from the
cytoplasm.
4
Substrate-level phosphorylation
2 NADH
4–6
Oxidative phosphorylation – Each NADH
produces net 3 ATP due to NADH
transport over the mitochondrial
membrane
2 NADH
6
Oxidative phosphorylation
2
Substrate-level phosphorylation
6 NADH
18
Oxidative phosphorylation
2 FADH2
4
Oxidative phosphorylation
36–38 ATP
From the complete oxidation of one
glucose molecule to carbon dioxide and
oxidation of all the reduced coenzymes.
Glycolysis preparatory
phase
Glycolysis pay-off
phase
Oxidative
decarboxylation of
pyruvate
Krebs cycle
Total yield
Sumber:
http://en.wikipedia.org/wiki/Aerobic_metabolism ….. Diunduh 24/4/2012
RESPIRASI ANAEROBIK
Anaerobic respiration is a form of respiration using electron acceptors other
than oxygen. Although oxygen is not used as the final electron acceptor, the
process still uses a respiratory electron transport chain; it is respiration without
oxygen.
In order for the electron transport chain to function, an exogenous final electron
acceptor must be present to allow electrons to pass through the system. In
aerobic organisms, this final electron acceptor is oxygen.
Molecular oxygen is a highly oxidizing agent and, therefore, is an excellent
acceptor.
In anaerobes, other less-oxidizing substances such as sulfate (SO42-), nitrate
(NO3-), or sulfur (S) are used. These terminal electron acceptors have smaller
reduction potentials than O2, meaning that less energy is released per oxidized
molecule. Anaerobic respiration is, therefore, in general energetically less
efficient than aerobic respiration.
Anaerobic respiration is used mainly by prokaryotes that live in environments
devoid of oxygen. Many anaerobic organisms are obligate anaerobes, meaning
that they can respire only using anaerobic compounds and will die in the
presence of oxygen.
KEPENTINGAN EKOLOGIS
Anaerobic respiration plays a major role in the global nitrogen, sulfur, and
carbon cycles through the reduction of the oxyanions of nitrogen, sulfur,
and carbon to more-reduced compounds.
Dissimilatory denitrification is the main route by which biologically fixed
nitrogen is returned to the atmosphere as molecular nitrogen gas.
Hydrogen sulfide, a product of sulfate respiration, is a potent neurotoxin
and responsible for the characteristic 'rotten egg' smell of brackish
swamps. Along with volcanic hydrogen sulfide, biogenic sulfide has the
capacity to precipitiate heavy metal ions from solution, leading to the
deposition of sulfidic metal ores.
Sumber: http://en.wikipedia.org/wiki/Anaerobic_respiration ….. Diunduh 24/4/2012
TIPE-TIPE RESPIRASI
type
lifestyle
electron acceptor
products
Eo' [V]
example organisms
aerobic
respiration
obligate and
facultative
aerobes
oxygen O2
H2O + CO2
+ 0.82
eukaryotes
+ 0.75
Geobacter,
Geothermobacter,
Geopsychrobacter,
Pelobacter
carbinolicus, P.
acetylenicus, P.
venetianus,
Desulfuromonadales,
Desulfovibrio
[iron] reduction
manganese
reduction
cobalt reduction
facultative
aerobes, obligate ferric iron Fe(III)
anaerobes
facultative or
obligate
anaerobes
facultative or
obligate
anaerobes
Fe(II)
Mn(IV)
Mn(II)
Desulfuromonadales,
Desulfovibrio
Co(III)
Co(II)
Geobacter
sulfurreducens
Geobacter
metallireducens,
Shewanella
putrefaciens,
(Desulfovibrio)
uranium reduction
facultative or
obligate
anaerobes
U(VI)
U(IV)
nitrate reduction
(denitrification)
facultative
aerobes
nitrate NO3−
nitrite NO2–
+ 0.40
Paracoccus
denitrificans, E. coli
fumarate
respiration
facultative
aerobes
fumarate
succinate
+ 0.03
Escherichia coli
sulfate respiration
obligate
anaerobes
sulfate SO42−
sulfide HS−
- 0.22
Desulfobacter latus,
Desulfovibrio' oxygen
methanogenesis
(carbonate
reduction)
methanogens
carbon dioxide
CO2
methane CH4
- 0.25
Methanothrix
thermophila
sulfur respiration
(sulfur reduction)
facultative
aerobes and
obligate
anaerobes
sulfur S0
sulfide HS−
- 0.27
Desulfuromonadales
acetogenesis
(carbonate
reduction)
acetogens
carbon dioxide
CO2
acetate
- 0.30
Acetobacterium woodii
TCA reduction
facultative or
obligate
anaerobes
trichloroacetic
acid
dichloroacetic
acid
Trichlorobacter
(Geobacteraceae)
Sumber: http://en.wikipedia.org/wiki/Anaerobic_respiration ….. Diunduh 20/4/2012
PERUBAHAN KIMIAWI DALAM
PENGKOMPOSAN
Penambahan Bulking Agents, Shredding the Substrates, dan Mixing
Generally, mixing of bulking agents such as woodchips, yard trimmings, bark,
rice hulls, municipal solid wastes or previously composted materials is used to
add a source of carbon, lower the moisture content, provide structural support,
increase porosity, and favor aeration. The composting method involves the use
of substrates that are fairly coarsely shredded to obtain biomasses with
interstitial spaces (homogeneous empty spaces) that account for more than
25% of the total volume of the biomass to be bio-oxidized. This is done in an
attempt to overcome the problem, commonly encountered with agglomerated
biomasses, of anaerobic fermentation occurring during the bio-oxidation stage.
1.
2.
3.
4.
5.
6.
. The principal limitations of all composting systems
currently in use are the following:
Poor, uneven aeration of the biomass;
Fluctuation of the temperature of the biomass during
the bio-oxidation stage;
Unsuitability of the system to the use of mycelial
microorganisms;
Few active contacts between
microorganisms/enzymes and substrate;
Little, if any, protection of the
enzymes/microorganisms from external agents;
Limited use of the capacity of the bioreactors.
Sumber:
….. Diunduh 20/4/2012
FAKTOR DEKOMPOSISI BAHAN ORGANIK
The reasons for these limitations have been identified and studied, as
follows:
1.
2.
3.
4.
5.
6.
The poor and uneven aeration of the biomass is due mainly to the fact
that during the bio-oxidative process, the "structure" of the solid
substrates loses its original characteristics. As a result, the substrates
tend to collapse and fall in on themselves or, in the case of rigid
substrates, tend to become compacted. Consequently, areas develop
where the substrates become compacted, reducing and/or eliminating
the interstitial spaces. The airflow is then reduced or blocked in these
areas.
The temperature fluctuations during the bio-oxidative stage are due to
the moisture initially present in the biomass evaporating during turning
(designed to break up the aggregated mass and aerate it at the same
time) and to conductive and convective phenomena developing in the
biomass.
The unsuitability of the system to the use of mycelial microorganisms is
due to the fact that the mycelium is damaged when the biomass is
turned and so prevented from developing to the optimal degree on the
surface of the substrate to be used and converted to useful biomass
and/or to a particular product.
The low number of active contacts between microorganisms/enzymes
and substrate is due mainly to the limited surface area of the substrate.
The lack of protection for the enzymes/microorganisms from external
agents is due mainly to the virtually non-existent porosity of the solid
substrates.
The limited use of the capacity of the bioreactors is linked to the need to
mix the biomass with bulking agents and/or to turn or stir the biomass.
Sumber:
http://en.wikipedia.org/wiki/Methanogenesis….. Diunduh 20/4/2012
PENANGANAN BAU DALAM PENGOMPOSAN
Odor is the major problem associated with composting. Adopting proper management options
can solve this problem.
Odor is usually produced because of anaerobic conditions. Sources of anaerobic odors include
a wide range of compounds, mainly ammonia, hydrogen sulphide, dimethyl disulphide,
methanethiol, volatile fatty acids, amines, and several aromatic compounds.
Odor usually originates from the site where it is stored and its storage condition prior to
composting. Once the ingredients are incorporated into the composting system, subsequent
odor problems are associated with the anaerobic conditions. Hence, it will be very essential to
bring them back to aerobic conditions.
The best way is to combine ingredients with coarse, dry bulking agents to increase porosity
and to allow sufficient oxygen penetration. Subsequent turning and forced aeration systems
can also provide sufficient oxygen. In addition to these conventional systems, oxidizing
chemicals like hydrogen peroxide, potassium permanganate, and chlorine can be used to
control the odor, but care should be taken not to kill the composting microorganisms. In situ
biological oxidation or biofilteration is also an effective method of controlling the bad odors.
Commercial enzyme catalysts and different biofiltering units, which can effectively reduce the
odors, are available in the market.
Methanogenesis or biomethanation is the formation of methane by microbes known as
methanogens. Organisms capable of producing methane have been identified only from
the domain Archaea, a group phylogenetically distinct from both eukaryotes and bacteria,
although many live in close association with anaerobic bacteria. The production of
methane is an important and widespread form of microbial metabolism. In most
environments, it is the final step in the decomposition of biomass.
Methanogenesis in microbes is a form of anaerobic respiration. Methanogens do not use
oxygen to respire; in fact, oxygen inhibits the growth of methanogens. The terminal
electron acceptor in methanogenesis is not oxygen, but carbon. The carbon can occur in a
small number of organic compounds, all with low molecular weights. The two best
described pathways involve the use of carbon dioxide and acetic acid as terminal electron
acceptors:
CO2 + 4 H2 → CH4 + 2H2O
CH3COOH → CH4 + CO2
However, methanogenesis has been shown to use carbon from other small organic
compounds, such as formic acid (formate), methanol, methylamines, dimethyl sulfide, and
methanethiol.
The biochemistry of methanogenesis is relatively complex, involving the following
coenzymes and cofactors: F420, coenzyme B, coenzyme M, methanofuran, and
methanopterin.
Sumber:
http://en.wikipedia.org/wiki/Methanogenesis….. Diunduh 20/4/2012
FAKTOR-FAK TOR PENGOMPOSAN
FAKTOR YANG MEMPENGARUHI PROSES PENGOMPOSAN
Setiap organisme pendegradasi bahan organik membutuhkan kondisi
lingkungan dan bahan yang berbeda-beda.
Apabila kondisinya sesuai, maka dekomposer tersebut akan bekerja giat untuk
mendekomposisi limbah padat organik.
Apabila kondisinya kurang sesuai atau tidak sesuai, maka organisme tersebut
akan dorman, pindah ke tempat lain, atau bahkan mati. Menciptakan kondisi
yang optimum untuk proses pengomposan sangat menentukan keberhasilan
proses pengomposan itu sendiri.
Rasio C/N
Rasio C/N yang efektif untuk proses pengomposan berkisar antara 30: 1
hingga 40:1. Mikroba memecah senyawa C sebagai sumber energi dan
menggunakan N untuk sintesis protein. Pada rasio C/N di antara 30 s/d
40 mikroba mendapatkan cukup C untuk energi dan N untuk sintesis
protein.
Apabila rasio C/N terlalu tinggi, mikroba akan kekurangan N untuk
sintesis protein sehingga dekomposisi berjalan lambat. Umumnya,
masalah utama pengomposan adalah pada rasio C/N yang tinggi,
terutama jika bahan utamanya adalah bahan yang mengandung kadar
kayu tinggi (sisa gergajian kayu, ranting, ampas tebu, dsb).
Untuk menurunkan rasio C/N diperlukan perlakuan khusus, misalnya
menambahkan mikroorganisme selulotik (Toharisman, 1991) atau
dengan menambahkan kotoran hewan karena kotoran hewan
mengandung banyak senyawa nitrogen.
Sumber:
http://en.wikipedia.org/wiki/Methanogenesis….. Diunduh 20/4/2012
FAKTOR-FAK TOR PENGOMPOSAN
Ukuran Bahan Kompos
Aktivitas mikroba berada diantara permukaan area dan udara. Permukaan
area yang lebih luas akan meningkatkan kontak antara mikroba dengan bahan
dan proses dekomposisi akan berjalan lebih cepat.
Ukuran partikel juga menentukan besarnya ruang antar bahan (porositas).
Untuk meningkatkan luas permukaan dapat dilakukan dengan memperkecil
ukuran partikel bahan tersebut.
MIKROBA PENGOMPOSAN
With the proper mixture of water, oxygen, carbon, and nitrogen, microorganisms are allowed to break down organic matter to produce
compost. The composting process is dependant on micro-organisms to
break down organic matter into compost. There are many types of
microorganisms found in active compost of which the most common
are:
1. Bacteria- The most numerous of all the micro organisms found in
compost.
2. Actinomycetes- Necessary for breaking down paper products such
as newspaper, bark, etc.
3. Fungi- Molds and yeast help break down materials that bacteria
cannot, especially lignin in woody material.
4. Protozoa- Help consume bacteria, fungi and micro organic
particulates.
5. Rotifers- Rotifers help control populations of bacteria and small
protozoans.
In addition, earthworms not only ingest partly composted material, but
also continually re-create aeration and drainage tunnels as they move
through the compost.
A lack of a healthy micro-organism community is the main reason why
composting processes are slow in landfills with environmental factors
such as lack of oxygen, nutrients or water being the cause of the
depleted biological community.
Sumber:
http://en.wikipedia.org/wiki/Compost….. Diunduh 20/4/2012
FAKTOR-FAK TOR PENGOMPOSAN
. Aerasi
Pengomposan yang cepat dapat terjadi dalam kondisi yang cukup
oksigen(aerob). Aerasi secara alami akan terjadi pada saat terjadi peningkatan
suhu yang menyebabkan udara hangat keluar dan udara yang lebih dingin
masuk ke dalam tumpukan kompos. Aerasi ditentukan oleh posiritas dan
kandungan air bahan(kelembaban). Apabila aerasi terhambat, maka akan
terjadi proses anaerob yang akan menghasilkan bau yang tidak sedap. Aerasi
dapat ditingkatkan dengan melakukan pembalikan atau mengalirkan udara di
dalam tumpukan kompos.
Mengapa oksigen sangat penting?
There are any very important reasons to keep compost aerobic, with oxygen
levels greater than 15%: When the oxygen is depleted ANaerobic bacteria take
over, and some of their byproducts are phytotoxic, toxic to plant growth, toxic
to germinating seeds. Some of these intermediate microbial metabolites are
VFA's, Volatile Fatty Acids. Many of the byproducts of anaerobic
decomposition are foul odors.
. Porositas
Porositas adalah ruang diantara partikel di dalam tumpukan kompos.
Porositas dihitung dengan mengukur volume rongga dibagi dengan volume
total. Rongga-rongga ini akan diisi oleh air dan udara. Udara akan
mensuplay Oksigen untuk proses pengomposan. Apabila rongga dijenuhi
oleh air, maka pasokan oksigen akan berkurang dan proses pengomposan
juga akan terganggu.
Sumber:
http://en.wikipedia.org/wiki/Methanogenesis….. Diunduh 20/4/2012
FAKTOR-FAK TOR PENGOMPOSAN
Kelembaban (Moisture content)
Kelembaban memegang peranan yang sangat penting dalam proses metabolisme mikroba
dan secara tidak langsung berpengaruh pada suplay oksigen. Mikrooranisme dapat
memanfaatkan bahan organik apabila bahan organik tersebut larut di dalam air.
Kelembaban 40 - 60 % adalah kisaran optimum untuk metabolisme mikroba. Apabila
kelembaban di bawah 40%, aktivitas mikroba akan mengalami penurunan dan akan lebih
rendah lagi pada kelembaban 15%. Apabila kelembaban lebih besar dari 60%, hara akan
tercuci, volume udara berkurang, akibatnya aktivitas mikroba akan menurun dan akan
terjadi fermentasi anaerobik yang menimbulkan bau tidak sedap.
Characterization of Compost From a Pilot Plant-Scale Composter
Utilizing Simulated Solid Waste
Burney S. Schwab, Carla J. Ritchie, D. James Kain, G. Chris Dobrin,
Lawrence W. King, Anna C. Palmisano
Waste Manag Res July 1994 vol. 12 no. 4 289-303
A pilot plant-scale composter using simulated solid waste was developed to
test the fate of consumer products such as disposable diapers.
The simulated waste consisted of a mixture of rabbit chow (which included
alfalfa), shredded newspaper, sand, and composted cow manure.
The compost mass self-heated from an ambient temperature of 27°C to about
55°C in the first 24 h. Dissolved ammonia levels, high in the early stages of
the process, began to decrease after about 4 weeks as nitrate concentration
began to increase. Both volatile solids and carbon:nitrogen ratios exhibited
gradual decreases with time. Microbial biomass, esterase activity, cellulose
mineralization, direct microscopic counts (AODC), and relative APIZYM
enzyme activity increased significantly in the first several days, and
maintained higher levels than initial measurements throughout the 22-week
testing period.
We concluded that the simulated solid waste underwent physical, chemical, and
microbiological changes that would be expected to occur in municipal solid waste
in a full-scale composting system. The pilot plant-scale composter should prove to
be a valuable tool in assessing the fate of products and materials under simulated
compost conditions.
Sumber: http://wmr.sagepub.com/content/12/4/289.abstract ….. Diunduh 20/4/2012
FAKTOR-FAK TOR PENGOMPOSAN
.. Temperatur/suhu
Panas dihasilkan dari aktivitas mikroba. Ada hubungan langsung antara
peningkatan suhu dengan konsumsi oksigen. Semakin tinggi temperatur akan
semakin banyak konsumsi oksigen dan akan semakin cepat pula proses
dekomposisi. Peningkatan suhu dapat terjadi dengan cepat pada tumpukan
kompos. Temperatur yang berkisar antara 30 - 60oC menunjukkan aktivitas
pengomposan yang cepat. Suhu yang lebih tinggi dari 60oC akan membunuh
sebagian mikroba dan hanya mikroba thermofilik saja yang akan tetap
bertahan hidup. Suhu yang tinggi juga akan membunuh mikroba-mikroba
patogen tanaman dan benih-benih gulma.
. Typical Time-Temperature Relationship for Composting Organic Wastes by the
Beltsville Aerated Pile Method. Curve 1 Indicates That Conditions of Moisture,
Temperature, C:N Ratio, and Aeration Are at Optimum Levels for Rapid Aerobic,
Thermophilic Composting. within Several Days, the Internal Pile Temperatures Increase
Rapidly from the Mesophilic (20 to 40°C) into the Thermophilic (&GT; 40°C) Stage, after
Which the Temperature Begins to Decline As Available Nutrients Are Depleted by the
Indigenous Microorganisms. Curve 2 Indicates What Might Happen When Certain
Parameters Are Deficient or Outside Their Optimum Range, Which Would Limit the
Growth and Activity of Microorganisms and Adversely Affect the Desired TimeTemperature Transition for Successful Composting.Sumber:
http://www.agnet.org/library/eb/394/
FAKTOR-FAK TOR PENGOMPOSAN
Kemasaman (pH )
Proses pengomposan dapat terjadi pada kisaran pH yang lebar. pH yang optimum untuk
proses pengomposan berkisar antara 6.5 sampai 7.5. pH kotoran ternak umumnya berkisar
antara 6.8 hingga 7.4. Proses pengomposan sendiri akan menyebabkan perubahan pada
bahan organik dan pH bahan itu sendiri.
Sebagai contoh, proses pelepasan asam, secara temporer atau lokal, akan menyebabkan
penurunan pH (pengasaman), sedangkan produksi amonia dari senyawa-senyawa yang
mengandung nitrogen akan meningkatkan pH pada fase-fase awal pengomposan. pH
kompos yang sudah matang biasanya mendekati netral.
Variability of Temperature, pH, and Moisture in an Aerobic Composting
Process (Steven H. Atchley and J. B. Clark. Appl Environ Microbiol. 1979
December; 38(6): 1040–1044. )
This study measured the environmental variability which exists in a commercial aerobic
composting process. The specific process studied is carried out in six decomposition cells
which present six different phases of the process. Temperature, pH, and moisture content
were determined in several randomly chosen sample sites in each cell, both at the
beginning and at the end of the time the material was left in the cell. Temperature and pH
varied greatly from one sample site to another in each cell, whereas moisture content was
less varied. A significant rise in both temperature and pH was observed at two stages of
degradation.
Sumber:
….. Diunduh 20/4/2012
Effects of pH Control On Composting of Garbage
Kiyohiko Nakasaki, Hideki Yaguchi, Yasushi Sasaki, Hiroshi Kubota
Waste Manag Res March 1993 vol. 11 no. 2 117-125
Composting experiments of garbage
were conducted by using a laboratory
scale reactor under well controlled
experimental conditions and the
effects of pH control were
quantitatively analysed.
In the pH
controlled
experiment,
lime was added
to prevent pH
decreasing
below 7,
especially at
the early stage
of composting.
The degradation rate of organic matter in the pH controlled experiment
was faster than that without. Nitrogen loss was enhanced by the control of
pH value, but the amount of promotion was relatively small.
The pH dependency on the activity of microorganisms, which contribute to
the composting rate, was investigated by using a liquid medium containing
glucose and proteins as nutrients.
The optimum pH for the growth rate and the degradation activity of
proteins of the microorganisms was in the range of 7-8, while the
decomposition of glucose proceeded rapidly at an early stage of
composting in a pH range from 6 to 9.
Sumber: http://wmr.sagepub.com/content/11/2/117 ….. Diunduh 22/4/2012
FAKTOR-FAK TOR PENGOMPOSAN
Kandungan Hara
Kandungan P dan K juga penting dalam proses pengomposan dan bisanya terdapat di
dalam kompos-kompos dari peternakan. Hara ini akan dimanfaatkan oleh mikroba selama
proses pengomposan.
Kandungan Bahan Berbahaya
Beberapa bahan organik mungkin mengandung bahan-bahan yang berbahaya bagi
kehidupan mikroba. Logam-logam berat seperti Mg, Cu, Zn, Nickel, Cr adalah beberapa
bahan yang termasuk kategori ini. Logam-logam berat akan mengalami imobilisasi selama
proses pengomposan.
.
Poultry Waste Management for Crop Production: Nigerian
Experience
G.O. Adeoye, M.K.C. Sridhar, O.E. Mohammed
Waste Manag Res March 1994 vol. 12 no. 2 165-172
Poultry wastes are posing serious environmental pollution problems in
Nigeria through offensive odours and promotion of fly and rodent
breeding.
Farmers normally dispose of their poultry wastes through heaping and
burning or dumping on the farm in the fresh state.
Experiments were conducted to stabilize the waste for 12 weeks by a
bag process similar to static pile composting either singly or amended
with sawdust or leaves.
Sawdust seems to be ideal for the production of a well stabilized
product which is environmentally safe. However, even the raw waste or
leaf amended waste if kept for 8 to 12 weeks produced a product which
has no adverse effect on the maize yield when applied at 20
tonnes/hectare.
The soils were improved through organic matter and retention of plant
nutrients.
Sumber: http://wmr.sagepub.com/content/12/2/165.abstract ….. Diunduh 25/4/2012
PRODUCTION OF FEED AND FERTILIZER FROM WATER HYACINTH PLANTS
IN THE TROPICS
C. Polprasert, N. Kongsricharoern, W. Kanjanaprapin
Waste Manag Res January 1994 vol. 12 no. 1 3-11
Water hyacinth grows ubiquitously in
natural water bodies in the tropics. If
allowed to propagate without control, it
can cause deterioration of water quality
and create problems with water uses.
However, water hyacinth has been used
for wastewater treatment, and as an
animal feed and soil conditioner.
This paper reports a
case study on
silaging and
composting of water
hyacinth plants
generated from
ponds treating pig
farm wastewater.
The water hyacinth plants mixed with molasses and pig manure at the
ratios of 85:10:5 (% wet weight) were found to be optimum for silage
production; the silaging period was 28 days.
The silaged products contained 16% protein and 18% dry matter, suitable
for use as animal feed. The composted water hyacinth plants, whose raw
materials included pig manure and leaves, contained N, P and K about
2.2, 1.5, and 0.8% (dry weight), respectively.
An economic analysis of the two recycling options suggested that some
benefits could be gained from these practices after 5 years of operation.
These two options were found to be technically and economically feasible
to be implemented at farm scale levels.
Sumber: http://wmr.sagepub.com/content/12/1/3.abstract ….. Diunduh 22/4/2012
Accelerated Composting of Grass Clippings By Controlling Moisture Level
Kiyohiko Nakasaki, Nobuto Aoki, Hiroshi Kubota
Waste Manag Res January 1994 vol. 12 no. 1 13-20
. Grass clippings were composted
with an autothermal packed bed type
laboratory-scale reactor in which a
desired temperature (60°C) is
maintained by controlling air flow
rate.
Effects of controlling
moisture level on
composting of grass
clippings were examined by
measuring changes in CO2
evolution rate, conversion
of carbon, HPLC pattern of
water soluble organic
matter and concentrations
of organic matter
constituents in the
composting solid, during
the composting process.
Time courses of CO2 evolution rate and conversion of carbon,
corresponding to total amount of organic matter decomposed, differed
substantially among the experimental runs with controlled different
moisture levels. The moisture level yielding the most rapid decomposition
of organic matter in the grass clippings was around 50% (W/W).
Analyses of HPLC pattern of water soluble organic matter and
concentrations of organic matter constituents in the composting solid also
indicated that the composting rate could be accelerated by keeping the
adequate moisture level.
Approximately 75% of cellulosic materials such as cellulose and hemicellulose were decomposed during a 194 h composting period under 50%
moisture conditions. Rather rapid decomposition of cellulosic materials,
which is characteristic of the composting of grass clippings, was
observed.
Sumber: http://wmr.sagepub.com/content/12/1/13.abstract ….. Diunduh 22/4/2012
FAKTOR-FAK TOR PENGOMPOSAN
Lama pengomposan
Lama waktu pengomposan tergantung pada karakteristik bahan yang
dikomposakan, metode pengomposan yang dipergunakan dan dengan atau
tanpa penambahan aktivator pengomposan. Secara alami pengomposan akan
berlangsung dalam waktu beberapa minggu sampai 2 tahun hingga kompos
benar-benar matang.
. Kondisi yang optimal untuk mempercepat proses pengomposan (Ryak,
1992)
Kondisi
Rasio C/N
Kelembaban
Konsentrasi
tersedia
oksigen
Ukuran partikel
Bulk Density
pH
Suhu
Sumber:
Konsisi yang bisa
diterima
Ideal
20:1 s/d 40:1
25-35:1
40 – 65 %
45 – 62 % berat
> 5%
> 10%
1 inchi
bervariasi
1000 lbs/cu yd
1000 lbs/cu yd
5.5 – 9.0
6.5 – 8.0
43 – 66oC
54 -60oC
….. Diunduh 20/4/2012
STRATEGI MEMPERCEPAT PENGOMPOSAN
Pengomposan dapat dipercepat dengan beberapa strategi. Secara umum
strategi untuk mempercepat proses pengomposan dapat dikelompokan
menjadi tiga, yaitu:
Menanipulasi kondisi/faktor-faktor yang berpengaruh pada proses
pengomposan.
Menambahkan Organisme yang dapat mempercepat proses pengomposan:
mikroba pendegradasi bahan organik dan vermikompos (cacing).
Menggabungkan strategi pertama dan kedua.
MEMANIPULASI KONDISI PENGOMPOSAN
Strategi ini banyak dilakukan di awal-awal berkembangnya teknologi
pengomposan. Kondisi atau faktor-faktor pengomposan dibuat seoptimum
mungkin. Sebagai contoh, rasio C/N yang optimum adalah 25-35:1.
Untuk membuat kondisi ini bahan-bahan yang mengandung rasio C/N
tinggi dicampur dengan bahan yang mengandung rasio C/N rendah,
seperti kotoran ternak. Ukuran bahan yang besar-besar dicacah sehingga
ukurannya cukup kecil dan ideal untuk proses pengomposan. Bahan yang
terlalu kering diberi tambahan air atau bahan yang terlalu basah
dikeringkan terlebih dahulu sebelum proses pengomposan. Demikian pula
untuk faktor-faktor lainnya.
Supplemental nutrition
The techniques mentioned above often need to be complemented by the
provision of nutrients. One of the most common practices is to add inorganic
fertilizers, particularly N, in order to modify a high C:N ratio. Similarly, P is
sometimes applied as the C:P ratio of the material mix is also considered
important (the ratio should be between 75:1 and 150:1). When micro-organisms
are inoculated, they require sugar and amino acids in order to boost their initial
activities; molasses is often added for this purpose.
Sumber: http://www.fao.org/docrep/007/y5104e/y5104e05.htm#TopOfPage ….. Diunduh 20/4/2012
STRATEGI MEMPERCEPAT PENGOMPOSAN
MENGGUNAKAN AKTIVATOR PENGOMPOSAN
Strategi yang lebih maju adalah dengan memanfaatkan organisme yang dapat
mempercepat proses pengomposan. Organisme yang sudah banyak
dimanfaatkan misalnya cacing tanah. Proses pengomposannya disebut
vermikompos dan kompos yang dihasilkan dikenal dengan sebutan kascing.
Organisme lain yang banyak dipergunakan adalah mikroba, baik bakeri,
aktinomicetes, maupuan kapang/cendawan.
Saat ini dipasaran banyak sekali beredar aktivator-aktivator pengomposan,
misalnya : Green Phoskko (GP-1), Promi, OrgaDec, SuperDec, ActiComp,
EM4, Stardec, Starbio, BioPos, dan lain-lain.
Promi, OrgaDec, SuperDec, dan ActiComp adalah hasil penelitian Balai
Penelitian Bioteknologi Perkebunan Indonesia (BPBPI) dan saat ini telah
banyak dimanfaatkan oleh masyarakat.
Aktivator pengomposan ini menggunakan mikroba-mikroba terpilih yang
memiliki kemampuan tinggi dalam mendegradasi limbah-limbah padat
organik, yaitu: Trichoderma pseudokoningii, Cytopaga sp, Trichoderma
harzianum, Pholyota sp, Agraily sp dan FPP (fungi pelapuk putih).
Mikroba ini bekerja aktif pada suhu tinggi (termofilik).
Aktivator yang dikembangkan oleh BPBPi tidak memerlukan tambahan
bahan-bahan lain dan tanpa pengadukan secara berkala. Namun,
kompos perlu ditutup/sungkup untuk mempertahankan suhu dan
kelembaban agar proses pengomposan berjalan optimal dan cepat.
Pengomposan dapat dipercepat hingga 2 minggu untuk bahan-bahan
lunak/mudah dikomposakan hingga 2 bulan untuk bahan-bahan
keras/sulit dikomposkan.
Sumber:
http://en.wikipedia.org/wiki/Methanogenesis….. Diunduh 20/4/2012
STRATEGI MEMPERCEPAT PENGOMPOSAN
Memanipulasi Kondisi dan Menambahkan Aktivator Pengomposan
Strategi proses pengomposan yang saat ini banyak dikembangkan adalah
mengabungkan dua strategi di atas. Kondisi pengomposan dibuat seoptimal
mungkin dengan menambahkan aktivator pengomposan.
Profil suhu dan populasi mikroba selama proses pengomposan
Panas dihasilkan dari aktivitas mikroba. Ada hubungan langsung antara peningkatan
suhu dengan konsumsi oksigen. Semakin tinggi temperatur akan semakin banyak
konsumsi oksigen dan akan semakin cepat pula proses dekomposisi. Peningkatan suhu
dapat terjadi dengan cepat pada tumpukan kompos.
Temperatur yang berkisar antara 30 - 60oC menunjukkan aktivitas pengomposan yang
cepat. Suhu yang lebih tinggi dari 60oC akan membunuh sebagian mikroba dan hanya
mikroba thermofilik saja yang akan tetap bertahan hidup.
Sumber: http://id.wikipedia.org/wiki/Kompos ….. Diunduh 20/4/2012
STRATEGI MEMPERCEPAT PENGOMPOSAN
Strategi pengomposan
Seringkali tidak dapat menerapkan seluruh strategi pengomposan di atas
dalam waktu yang bersamaan. Ada beberapa pertimbangan yang dapat
digunakan untuk menentukan strategi pengomposan:
1.
2.
3.
4.
Karakteristik bahan yang akan dikomposkan.
Waktu yang tersedia untuk pembuatan kompos.
Biaya yang diperlukan dan hasil yang dapat dicapai.
Tingkat kesulitan pembuatan kompos
Strategi Mempercepat Proses Pengomposan
Pengomposan dapat dipercepat dengan beberapa strategi. Secara umum
strategi untuk mempercepat proses pengomposan dapat dikelompokan
menjadi tiga, yaitu:
1. Menanipulasi kondisi/faktor-faktor yang berpengaruh pada proses
pengomposan.
2. Menambahkan Organisme yang dapat mempercepat proses
pengomposan: mikroba pendegradasi bahan organik dan
vermikompos (cacing).
3. Menggabungkan strategi pertama dan kedua.
Memanipulasi Kondisi Pengomposan
Kondisi atau faktor-faktor pengomposan direkayasa menjadi seoptimum
mungkin. Misalnya rasio C/N yang optimum adalah 25-35:1. Untuk
membuat kondisi ini bahan-bahan yang mengandung rasio C/N tinggi
dicampur dengan bahan yang mengandung rasio C/N rendah, seperti
kotoran ternak.
Ukuran bahan direkayasa sehingga ukurannya cukup kecil dan ideal
untuk proses pengomposan. Bahan yang terlalu kering diberi tambahan
air atau bahan yang terlalu basah dikeringkan terlebih dahulu sebelum
proses pengomposan. Demikian pula untuk faktor-faktor lainnya.
Sumber: http://id.wikipedia.org/wiki/Kompos ….. Diunduh 20/4/2012
MODEL DEKOMPOSISI BAHAN ORGANIK
Lines indicate OM fluxes, with the dashed line signifying the OM flux associated with
enzyme production and its contribution to OM depolymerisation. Red arrows (and red
arrowheads) indicate that rates accelerate with increasing temperature while those in blue
indicatethat rates slow with warming temperatures. Black arrows are fluxes for which
temperature controls are poorly understood (e.g., type of OM released from chemical
protection) or beyond the scope of this review (plant inputs). Physical protection slows
depolymerization of otherwise available SOM and exchange of chemically protected SOM,
but its response to temperature is not well understood. Temperature response of chemical
protection varies as a function of the type of binding (covalent bonds are effectively
irreversible on short time-frames) and bonding affinity (temperature effects on diffusion
processes dominate for low-affinity mineral-bound SOM while desorption dynamics
dominate for high-affinity SOM). As physiochemically protected SOM becomes available for
decomposition some may be assimilable, but we expect that most will require
depolymerization before it can be assimilated by microbes.
Sumber: Temperature and soil organic matter decomposition rates – synthesis of current
knowledge and a way forward. RICHARD T. CONANT dkk. Global Change Biology (2011) 17,
3392–3404, doi: 10.1111/j.1365-2486.2011.02496.x
KATALISIS ENSIMATIS
Bagan (a) Representation of the negative relationship between enzyme-binding
ability and catalytic rate as a result of the trade-off between enzyme
conformational structures that maintain binding (as opposed to non-binding)
states vs. higher reaction rates.
Bagan (b) Idealized thermal sensitivities of the activities of respiratory enzymes
resulting as a consequence of the trade-off shown in (a) [based on Angilletta
(2009)], where the black curve is from the coolest environment and the dothatch blue curve from the warmest.
Sumber: Temperature and soil organic matter decomposition rates – synthesis of current
knowledge and a way forward. RICHARD T. CONANT dkk. Global Change Biology (2011) 17,
3392–3404, doi: 10.1111/j.1365-2486.2011.02496.x
PENGOMPOSAN
Composting is the process of controlled aerobic decomposition of
biodegradable organic matter
During composting, microorganisms break down organic matter into
carbon dioxide, water, heat, and compost:
Organic matter + O2
Compost + CO2 + H2O + NO3- + SO42- + heat
ORGANIC MATTER DECOMPOSITION: INTERACTIONS OF
TEMPERATURE, MOISTURE AND SUBSTRATE TYPE
Travis Roberts, Professional MS Student
Soil and Water Science Department, University of Florida
The decomposition of organic matter is a major biogeochemical process because of its effect
on ecosystem productivity and its implications on climate change. Temperature and moisture
are two variables that have a tremendous influence on microbial decomposition.
Decomposition is also influenced by substrate type, in which higher quality substrates often
have greater decomposition than lower quality substrates.
Pine and hardwood litters, popsicle sticks, aspen and pine wood stakes were subjected to 4
temperature treatments (10ºC, 20ºC, 30ºC, and 40ºC) and 4 moisture content treatments (wet
23-28%, moist 15-20%, dry 3-7%, & fluxing between 3-7% and 23-28% saturation ) over the
course of 30 months, in order to determine the influence of temperature, moisture, and
substrate type on decomposition. As a subset of the experiment soil respiration was recorded
from one pvc collar with leaf litter and one without litter and was subjected to the same
treatments.
There were different responses with different substrates, but overall microbial decomposition
was greatest at the highest temperatures. For the wood substrates the “moist” and “dry”
moisture contents generally produced the highest mass losses. The pvc collar’s highest soil
respiration rates were with the “wet” moisture treatment. Temperature and moisture are both
significant in decomposition, but the moisture relationship interaction with decomposition is
much harder to understand.
Sumber: http://soils.ifas.ufl.edu/academics/pdf/Non-Thesis%20Projects/Travis%20Roberts.pdf …..
Diunduh 23/4/2012
BAHAN-BAHAN UNTUK PENGOMPOSAN
Food and drink industry waste;
Paper, card, timber and other biodegradable waste;
Limbah rumah tangga;
Organic sludge including sewage;
Limbah atau sisa-sisa pertanian.
: Wastes from meat, dairy products, and eggs should not be
used in household compost:
they attract unwanted vermin;
they do not appropriately decompose in the time
required.
Biodegradability of the Organic Fraction of Municipal Solid Waste in a
High-Solids Anaerobic Digester
Masoud Kayhanian
Waste Manag Res March 1995 vol. 13 no. 2 123-136
Three methods were used to estimate the ultimate biodegradability of the
organic fraction of municipal solid waste.
These methods included: long-term batch digestion studies, measurement of
lignin content, and chemostat studies. The ultimate biodegradability values
obtained from these methods were compared to a field operation using a pilot
scale, high-solids, complete-mix, thermophilic, anaerobic digestion process.
The biodegradability obtained from the pilot study, at a mass retention
time of 30 days, was approximately 83 and 81% of the estimated values
obtained from the lignin content and the batch study, respectively.
In addition, it has been shown that the contents of the biodegradable
volatile solids affects the prediction of biogas production rate, the
computation of the organic loading rate, and feedstock C/N ratio. .
Sumber: http://wmr.sagepub.com/content/13/2/123.abstract ….. Diunduh 20/4/2012
DEKOMPOSER
Mikroba asdalah kunci dari proses pengomposan
Klasifikasi mikroba menurut konsumsi oksigen nya:
Aerobik: Mikroba menggunakan oksigen untuk
metabolismenya
Anaerobik: Mikroba dapat hidup aktif dalam lingkungan
tanpa oksigen bebas.
RELATIONSHIP OF MICROBIAL MASS AND ACTIVITY IN
BIODEGRADATION OF SOLID WASTE
R.J. Murphy, D.E. Jones, R.I. Stessel
Waste Manag Res September 1995 vol. 13 no. 5 485-497
Limited landfill space and resistance to siting such facilities has spurred
consideration of new approaches to increase the longevity of landfills. Such
efforts have included exploring methods to enhance degradation rates of
municipal solid waste (MSW) and subsequently, mining landfills to recover
materials and landfill space.
Microbial mass and activity of MSW incubated in lysimeters, with moisture
content sustained with recycled leachate, were compared under anaerobic and
aerobic conditions in this study. Bacterial biomass and number were quantified
by adenosine triphosphate analysis and acridine orange direct counts. Viability,
adenylate energy charge and cellulase activity were also assessed.
Bacterial number and energy status were lower in the anaerobic system.
Cellulase activity in the anaerobic lysimeter decreased to undetectable levels
while activity in the aerobic system continued to increase throughout the 92day experiment.
The results indicated that aeration, even at a relatively low volume, with
leachate recirculation, significantly accelerated degradation of MSW.
Furthermore, the results demonstrated the potential of using cellulase
activity as a surrogate parameter of relative microbial activity of MSW
degradation.
Sumber: http://wmr.sagepub.com/content/13/5/485.abstract ….. Diunduh 20/4/2012
Klasifikasi Mikroba menurut kondisi thermal
kehidupannya:
Mikroba
 Psychrophiles
 Mesophiles
 Thermophiles
Kisaran Temperatur untuk
aktivitasnya, оС
0 - 30
30 – 45
45 – 50
Waste Manag. 2008;28(8):1411-6. Epub 2007 Sep 27.
Optimum moisture levels for biodegradation of mortality composting
envelope materials.
Ahn HK, Richard TL, Glanville TD.
Moisture affects the physical and biological properties of compost and other
solid-state fermentation matrices. Aerobic microbial systems experience
different respiration rates (oxygen uptake and CO2 evolution) as a function of
moisture content and material type. In this study the microbial respiration rates
of 12 mortality composting envelope materials were measured by a pressure
sensor method at six different moisture levels. A wide range of respiration (1.694.2mg O2/g VS-day) rates were observed for different materials, with alfalfa
hay, silage, oat straw, and turkey litter having the highest values. These four
envelope materials may be particularly suitable for improving internal
temperature and pathogen destruction rates for disease-related mortality
composting. Optimum moisture content was determined based on
measurements across a range that spans the maximum respiration rate. The
optimum moisture content of each material was observed near water holding
capacity, which ranged from near 60% to over 80% on a wet basis for all
materials except a highly stabilized soil compost blend (optimum around 25%
w.b.). The implications of the results for moisture management and process
control strategies during mortality composting are discussed.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/17900890 ….. Diunduh 28/4/2012
PERTUMBUHAN MIKROBA SELAMA PROSES
PENGOMPOSAN
Microorganisms
BACTERIA
Mesophiles
Thermophiles
ACTINOMICETES
Thermophiles
FUNGI
Mesophiles
Thermophiles
Populations according to the thermal
conditions
<40 оС
40 - 70 оС
108
104
106
109
104
108
106
106
103
107
Biotechnol Bioeng. 2004 Nov 20;88(4):520-7.
Monitoring the biological activity of the composting process: Oxygen
uptake rate (OUR), respirometric index (RI), and respiratory quotient (RQ).
Gea T., Barrena R, Artola A, Sánchez A.
Composting of several organic wastes of different chemical composition
(source-separated organic fraction of municipal solid waste, dewatered raw
sludge, dewatered anaerobically digested sludge and paper sludge) was
carried out under controlled conditions to study the suitability of different
biological indexes (oxygen uptake rate, respirometric index, and respiratory
quotient) to monitor the biological activity of the composting process. Among
the indexes tested, oxygen uptake rate (also referred to as dynamic
respirometric index) provided the most reliable values of microbial activity in a
compost environment. On the other hand, values of the static respirometric
index measured at process temperature, especially in the early stages of the
composting process, were significantly lower than those of the dynamic index,
which was probably due to oxygen diffusion limitations present in static
systems. Both static and dynamic indexes were similar during the maturation
phase. Static respirometric index measured at 37 degrees C should not be
used with samples obtained during the thermophilic phase, since it resulted in
an underestimation of the respiration values. Respiratory quotient presented
only slight variations when changing the process temperature or the waste
considered, and its use should be restricted to ensure aerobic conditions in the
composting matrix.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/15459907 ….. Diunduh 28/4/2012
Bacteria
Heterotrophic
Autotrophic
Aerobic
Anaerobic
Kemampuan pertumbuhannya sangat besar opada media lembab
Spektrum aktivitasnya sangat luat
Aktif pada kondisi kisaran pH yang luas
Sulit beradaptasi pada kondisi media masam
BIOREMEDIATION OF OLIVE-MILL WASTEWATERS BY
COMPOSTING
U. Tomati, E. Galli, L. Pasetti, E. Volterra
Waste Manag Res November 1995 vol. 13 no. 6 509-518
Olive-mill wastewaters (O.M.W.) containing about 7% solids were composted
with wheat straw in a forced aeration static pile. Two percent urea was added
to ensure a C/N ratio of about 35. To avoid overdosing with water, a fraction of
the O.M.W. equal to the weight of the straw was added initially. When
composting had reached the thermophilic phase, additional doses of O.M.W.
were added every 3 days as water evaporated.
The ratio of O.M.W. solids:straw approached 1:1 and the thermophilic phase
was extended to 35 days. Temperature, oxygen consumption, pH, C/N, total
organic carbon, total extractable carbon, humic and fulvic acids and lignin
degradation were followed during the process. The humification was assayed
following the degree of humification, the humification rate and the humification
index which respectively reached the values of 78%, 37.8% and 0.28 after 2
months.
Humic acids were characterized by their elemental composition and molecular
weight. A lignin degradation of about 70% was assayed at the end of the
thermophilic phase. No phytotoxicity was recorded on the end product, the
chemical and physical properties of which suggest its possible use as fertilizer.
Sumber: http://wmr.sagepub.com/content/13/6/509.abstract ….. Diunduh 20/4/2012
Fungi
Fermenting fungi
Ragi = Yeast
Mampu hidup pada medium yang kandungan airnya rendah;
Kompetitor bagi bakteri heterotrophic
Aktif pada konduisi pH 2 – 9;
Kebutuhan nitrogen nya rendah
ENUMERATION OF ANAEROBIC REFUSE-DECOMPOSING MICROORGANISMS ON REFUSE CONSTITUENTS
Xingdong Qian, Morton A. Barlaz
Waste Manag Res March 1996 vol. 14 no. 2 151-161
Hydrolytic, acetogenic and methanogenic bacteria are required for the
conversion of refuse to methane in landfills. In order to identify sources of
these trophic groups in refuse, the total anaerobic population and the subpopulations of cellulolytic, hemicellulolytic, butyrate catabolizing acetogenic,
and acetate- and H2-CO2 -utilizing methanogenic bacteria as present on grass,
leaves, branches, food waste, whole refuse and two landfill cover soils were
enumerated by the most probable number (MPN) technique. Total anaerobes
ranged from 10 3 cells per dry gram in cover soil to 109 in grass, food waste
and fresh refuse.
Hemicellulolytics ranged from 160 cells per dry gram in cover soil to 109 in
grass. The highest cellulolytic population was measured on branches (316 cells
per dry gram), while the maximum acetogenic population was measured on
leaves (2.5 x 104).
The highest methanogen populations were measured on leaves (6.3 x 103) and
one of two fresh refuse samples (105).
Yard waste was the major carrier of the trophic groups required for refuse
decomposition, while the cover soils tested did not represent major inputs of
the requisite bacteria to landfills.
Sumber: http://wmr.sagepub.com/content/14/2/151.abstract ….. Diunduh 20/4/2012
Actinomycetes
Aerobic and thermophilic;
They are assimilated by bacteria and fungi;
use organic nitrogen;
Active in neutral and slightly alkaline media;
Act in the ending phase of the composting process.
Waste Manag Res. 2006 Feb;24(1):37-47.
THE USE OF RESPIRATION INDICES IN THE COMPOSTING
PROCESS: A REVIEW.
Barrena Gómez R, Vázquez Lima F, Sánchez Ferrer A.
Respiration is directly related to the metabolic activity of a microbial population.
Micro-organisms respire at higher rates in the presence of large amounts of
bioavailable organic matter while respiration rate is slower if this type of
material is scarce. In the composting process respiration activity has become
an important parameter for the determination of the stability of compost. It is
also used for the monitoring of the composting process and it is considered an
important factor for the estimation of the maturity of the material. A wide range
of respirometric protocols has been reported based either on CO2 production,
O2 uptake or release of heat. The most common methods are those based on
O2 uptake.
Respirometric assays are affected by a number of parameters
including temperature, humidity, and both incubation and preincubation conditions. Results from respirometries are
generally expressed as 'respiration indices', most of them with
their own units and basis. In consequence, some confusion
exists when referring and comparing respiration indices.
This is particularly important because current and future legislations define and
measure the biological stability of waste on the basis of respiration activity of
the material. This paper discusses and compares most common respiration
indices currently used.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/16496869 ….. Diunduh 28/4/2012
Pelaku lain dalam proses dekomposisi bahan organik
Duckweeds (algae)
Cyanophytes
Prothozoe
Enzymes
COMPOSTING OF < 100 MM FRACTION OF MUNICIPAL
SOLID WASTE
S. Mato, D. Otero, M. Garcia
A low cost solution for management of municipal solid waste in small
municipalities was investigated; composting experiments were done
using domestic waste.
Particles > 100 mm were removed, the screened substrate ( < 100 mm)
was used for composting experiments on static piles.
The results have shown that the size of waste does not affect
composting. Though the inert material left greatly adds to the
porosity, rainfall does not markedly affect the process; in fact
excessive dryness gave the least stable end product, and total
nitrogen, ammoniacal nitrogen and phosphorus content were the
best pointers to the instability.
Sumber: http://wmr.sagepub.com/content/12/4/315.abstract ….. Diunduh 20/4/2012
Shredding
Downsizing, or chopping up the materials, is a sound and widelypractised technique. It increases the surface area available for
microbial action and provides better aeration. This technique is
particularly effective and necessary for harder materials such as
wood.
Diunduh dari: http://www.fao.org/docrep/007/y5104e/y5104e05.htm
I. Fase Pertama: Aktif (Termofilik)
1.
2.
3.
4.
5.
Pelaku utamanya mikroba aerobik;
Terjadi proses Dekomposisi bahan organik (asam organik, asam amino,
sakarida);
Mengkonsumsi oksigen dan melepaskan CO2 dan energi;
Proses dekompiosisi berlangsung cepat;
Temperatur dapat mencapai 55-60° С.
Kinetic Study of the Composting of Evergreen Oak Forestry Waste
M.-J. Martinez-Iñigo, G. Almendros
Waste Manag Res July 1994 vol. 12 no. 4 305-314
The successive stages in the composting process of forestry waste from
evergreen oak (Quercus ilx sbsp. ballota) were studied under controlled
conditions (initial) carbon to nitrogen ratio = 30, T= 27°C).
The original material was composted for 6 months and sampled every 15 days.
The variables measured on the oak biomass in the course of the experiment
showed different kinetics: the weight loss and germination index underwent a
monotonic increase whereas the reducing sugars, phenols and E465/ E665
extinction ratio of the water-soluble fraction stabilized at their lowest values
after the first 2 weeks. Other variables, such as alkali solubility, water
repellency, pH and particle size, showed maximum or minimum values at
intermediate stages of the experiment. In contrast to the adverse agrobiological
effects of the direct application to soil of the original waste, germination biotests
and greenhouse experiments showed that plant response improved from the 2
first weeks of composting.
The kinetics observed for the parameters studied suggested that the less
favourable effect on plant yield may come from phytotoxic substances in
compost but also from the microbial use of soil N required for the
transformation of the most biodegradable compost fractions in special
hemicelluloses.
Sumber: http://wmr.sagepub.com/content/12/4/305.abstract ….. Diunduh 20/4/2012
Perubahan Temperatur selama fase pertama proses
dekomposisi biomasa yang tingkat fermentasinya rendah
atau tinggi
The active composting stage is followed by a curing stage, and the pile
temperature decreases gradually. The start of this phase is identified when
turning no longer reheats the pile. At this stage, another group of thermophilic
fungi starts to grow. These fungi bring about a major phase of decomposition of
plant cell-wall materials such as cellulose and hemi-cellulose. Curing of the
compost provides a safety net against the risks of using immature compost
such as nitrogen (N) hunger, O deficiency, and toxic effects of organic acids on
plants.
Eventually, the temperature declines to ambient temperature. By the time
composting is completed, the pile becomes more uniform and less active
biologically although mesophilic organisms recolonize the compost. The
material becomes dark brown to black in colour. The particles reduce in size
and become consistent and soil-like in texture. In the process, the amount of
humus increases, the ratio of carbon to nitrogen (C:N) decreases, pH
neutralizes, and the exchange capacity of the material increases.
Sumber: http://www.fao.org/docrep/007/y5104e/y5104e05.htm ….. Diunduh 26/4/2012
Temperature and soil organic matter decomposition rates –
synthesis of current knowledge and a way forward
Richard T. Conant , Michael G. Ryan, Göran I. Ågren, Hannah E. Birge, Eric A. Davidson, Peter
E. Eliasson, Sarah E. Evans, Serita D. Frey, Christian P. Giardina, Francesca M. Hopkins, Riitta
Hyvönen, Miko U. F. Kirschbaum, Jocelyn M. Lavallee, Jens Leifeld, William J. Parton, Jessica
Megan Steinweg, Matthew D. Wallenstein, J. Å. Martin Wetterstedt, Mark A. Bradford.
Global Change Biology. Volume 17, Issue 11, pages 3392–3404, November 2011
The response of soil organic matter (OM) decomposition to
increasing temperature is a critical aspect of ecosystem responses
to global change. The impacts of climate warming on
decomposition dynamics have not been resolved due to apparently
contradictory results from field and lab experiments, most of which
has focused on labile carbon with short turnover times. But the
majority of total soil carbon stocks are comprised of organic carbon
with turnover times of decades to centuries. Understanding the
response of these carbon pools to climate change is essential for
forecasting longer-term changes in soil carbon storage. Herein, we
briefly synthesize information from recent studies that have been
conducted using a wide variety of approaches.
In our effort to
understand research todate, we derive a new
conceptual model that
explicitly identifies the
processes controlling
soil OM availability for
decomposition and
allows a more explicit
description of the
factors regulating OM
decomposition under
different circumstances.
It explicitly defines resistance of soil OM to decomposition as being due either to its
chemical conformation (quality) or its physico-chemical protection from decomposition.
The former is embodied in the depolymerization process, the latter by
adsorption/desorption and aggregate turnover.
We hypothesize a strong role for variation in temperature sensitivity as a function of
reaction rates for both. We conclude that important advances in understanding the
temperature response of the processes that control substrate availability,
depolymerization, microbial efficiency, and enzyme production will be needed to predict
the fate of soil carbon stocks in a warmer world.
Sumber: http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2486.2011.02496.x/abstract ….. Diunduh
22/4/2012
FASE KE DUA PROSES DEKOMPOSISI: Cooling
Dekomposisi molekul organik yang lebih kompleks;
Kebanyakan mikroba mati kekurangan makanan;
Proses dekomposisi berlangsung lambat;
Temperatur mencapai 40 - 45° С;
Durasinya: beberapa minggu
: humifikasi
Wujud bahan organik sebelum dan setelah Pengomposan
FASE KE TIGA: PEMATANGAN
Temperatur sama dengan suhu ambient;
Hasilnya berupa kompos matang dengan
kualitas bagus
Temperature changes and fungi populations in wheat straw compost.
Solid line = temperature; broken line = mesophilic fungi population; dotted line = thermophilic
fungi population; left y-axis = fungal populations (logarithm of colony forming units (cfu) per
gram of compost plated onto agar); right y-axis = temperature in centre of compost. a, b, c and
d = heating phases.
Source: http://helios.bto.ed.ac.uk/bto/microbes/thermo.htm
The aerobic composting process starts with the formation of the pile. In many cases, the
temperature rises rapidly to 70-80 °C within the first couple of days. First, mesophilic
organisms (optimum growth temperature range = 20-45 °C) multiply rapidly on the readily
available sugars and amino acids. They generate heat by their own metabolism and raise the
temperature to a point where their own activities become suppressed. Then a few thermophilic
fungi and several thermophilic bacteria (optimum growth temperature range = 50-70 °C or
more) continue the process, raising the temperature of the material to 65 °C or higher. This
peak heating phase is important for the quality of the compost as the heat kills pathogens and
weed seeds.
(diunduh dari: http://www.fao.org/docrep/007/y5104e/y5104e05.htm 26/4/2012)
PARAMETER PENGENDALI KOMPOSTING
1. Porosity of substrate (free volume) – defined by
the spaces inside the biomass occupied by air
and water.
General porosity Pg - the relation of empty spaces
volume Vv and the whole biomass volume Vt:
Pg = Vv / Vt , %
Free air space (FAS), Vf - the biomass
volume, which is occupied by the air:
(Vv –Va) / Vt
Va – volume,
occupied by water
Porosity depends on:
Particle size distribution;
Level of humidity;
Height of the pail.
Sumber:
….. Diunduh 20/4/2012
1. The particle
size distribution,
bulk density, and
porosity of a
compost mixture
are group of
factors that can
lead to anaerobic
conditions.
2. These physical
characteristics of
the compost
mixture can
interact with high
moisture levels to
reduce oxygen
transport.
Effective cross sectional area as a function of particle size
distribution, shape, and packing density
Sumber:
….. Diunduh 20/4/2012
2. AIR - KELEMBABAN
Air merupakan salah satu komponen penting bagi
kehidupan mikroba, karena:
•
Air diperlukan dalam proses pertukaran unsur hara melalui membran sel;
•
Air menjadi media transport bagi ensim-ensim ekstra-seluler;
•
Air menjadi medium bagi senyawa-senyawa larut;
•
Air diperlukan untuk berlangsungnya reaksi-reaksi kimia
< 40% moisture – degradation will proceed at a
slow rate (under 25 -30% it stops);
> 65% moisture - О2 distributes very difficult
in the biomass (anaerobic conditions
established)
Factors affecting aerobic composting
Aeration
Aerobic composting requires large amounts of O, particularly at the initial
stage. Aeration is the source of O, and, thus, indispensable for aerobic
composting. Where the supply of O is not sufficient, the growth of aerobic
micro-organisms is limited, resulting in slower decomposition. Moreover,
aeration removes excessive heat, water vapour and other gases trapped in
the pile. Heat removal is particularly important in warm climates as the risk
of overheating and fire is higher. Therefore, good aeration is indispensable
for efficient composting. It may be achieved by controlling the physical
quality of the materials (particle size and moisture content), pile size and
ventilation and by ensuring adequate frequency of turning.
Moisture
Moisture is necessary to support the metabolic activity of the microorganisms. Composting materials should maintain a moisture content of 4065 percent. Where the pile is too dry, composting occurs more slowly, while
a moisture content in excess of 65 percent develops anaerobic conditions.
In practice, it is advisable to start the pile with a moisture content of 50-60
percent, finishing at about 30 percent.
(diunduh dari: http://www.fao.org/docrep/007/y5104e/y5104e05.htm)
The effect of aqueous film thickness on anaerobic odor production
Metabolic
Regions as a
function of
moisture
content
In a properly moist compost
matrix, the particles (brown)
are surrounded by aqueous films
(blue), but are separated by air
filled pores (white)
Anaerobic zones (purple dots) are
created as increasing water
content fills small pores, so
oxygen must diffuse farther
through water.
Composting may be divided into two categories by the nature of the
decomposition process. In anaerobic composting, decomposition occurs
where oxygen (O) is absent or in limited supply.
Under this method, anaerobic micro-organisms dominate and develop
intermediate compounds including methane, organic acids, hydrogen sulphide
and other substances. In the absence of O, these compounds accumulate and
are not metabolized further.
Many of these compounds have strong odours and some present
phytotoxicity. As anaerobic composting is a low-temperature process, it
leaves weed seeds and pathogens intact. Moreover, the process usually takes
longer than aerobic composting.
These drawbacks often offset the merits of this process, viz. little work
involved and fewer nutrients lost during the process.
Sumber: http://www.fao.org/docrep/007/y5104e/y5104e05.htm ….. Diunduh 26/4/2012
JUMLAH OKSIGEN
C6H12O6 + 6O2 → 6CO2 + 6H2O + 2 800 KJ/mol
To treat 1kg organic matter 1,6 kg of O2 are
required !
Oxygen requirement during
the composting process:
First stage – 5 - 15%
Second stage – 1 - 5%
O2 could be supplied
by means of:
Air: 10 – 100 N.m3/h
Mechanical mixing;
Forced ventilation
(aeration )
Result:
Complete mineralization?
Humification?
Temperature:
Temperature is a key parameter determining the
success of composting process!
Heat is produced as a by-product of the
microbial breakdown of organic material
Defines the thermophilic stage of the composting process;
Easy to monitor
Provides disinfection of the product - at 55C almost all
pathogenic are killed;
Kills the weeds’ seeds at 65C and more
: t > 70C kills also
First stage: 55-65C
Second stage: 35 - 45C
t< 25C
end of the
composting process
bacteria responsible for
composting process!
Values of released energy for
main substances:
Glucosis
19 kJ/g
Lipides
39 kJ/g
Proteines
23 kJ/g
M. Koleva ERASMUS’07
Temperature and pH profiles during composting
Ratio C/N, C/P and C/S
 naturally existing in biomass
C/N:
30 atoms C : 1 atom N
C – source of energy for heterotrophic microorganisms;
N – important for syntesis of protheins
1/3 digunakan oleh
mikroba
C
2/3 menjadi CO2
•Excess of N
that leads to
release of NH3
C/N < 30
•NH3 is
stimulated by:
 t ,  N, pH
C/N > 30
Optimal ratio C/N:
•at the start 25 -30
Carbon-to-nitrogen ratios may need to be adjusted
•At the end < 20 (10:1)
depending on the bioavailability of these elements !!!
C/P:
C/S:
P acts as a catalyst of
biochemical reactions!
Optimal ratio: 100 < C/S< 300
Optimal ratio: 100 <
C/P< 200
Typical C/N ratios for common compost materials
Materials High in Carbon
C/N*
autumn leaves
30-80:1
straw
40-100:1
wood chips or sawdust
100-500:1
bark
100-130:1
mixed paper
150-200:1
newspaper or corrugated cardboard
560:1
Materials High in Nitrogen
C:N*
vegetable scraps
15-20:1
coffee grounds
20:1
grass clippings
15-25:1
manure
5-25:1
Source: Dickson, N., T. Richard, and R. Kozlowski. 1991.
Composting to Reduce the Waste Stream: A Guide to Small Scale
Food and Yard Waste Composting
Sumber:
….. Diunduh 20/4/2012
KEMASAMAN : pH
I st period: pH value
decreases
pH
The reason: generation
of CO2
9
8
7
II nd period: pH value
increases up to 8-9
6
The reason: generation
of NH3
I
5
0
II
Time
Compost
microorganisms
operate best under
neutral to acidic
conditions!
Optimal values of pH are:
pH max  8.5
at the beginning pH 5.5  8
at the end: pH  7
Factors Leading to Anaerobic Conditions
1. Inadequate
porosity
2. Excessive
pile size
3. Excess
moisture
reduces
oxygen
penetration
Sumber:
….. Diunduh 20/4/2012
Oxygen is
consumed
much more
rapidly
4. Rapidly
degrading
substrate
Environ Pollut. 2004 May;129(2):305-14.
Methane oxidation and formation of EPS in compost: effect of oxygen
concentration.
Wilshusen JH, Hettiaratchi JP, De Visscher A, Saint-Fort R.
. Oxygen concentration plays an important role in the regulation of methane
oxidation and the microbial ecology of methanotrophs. However, this effect is
still poorly quantified in soil and compost ecosystems.
The effect of oxygen on the formation of exopolymeric substances (EPS) is as
yet unknown. We studied the effect of oxygen on the evolution of
methanotrophic activity.
At both high and low oxygen concentrations, peak
activity was observed twice within a period of 6 months.
Phospholipid fatty acid analysis showed that there was
a shift from type I to type II methanotrophs during this
period. At high oxygen concentration, EPS production
was about 250% of the amount at low oxygen
concentration. It is hypothesized that EPS serves as a
carbon cycling mechanism for type I methanotrophs
when inorganic nitrogen is limiting. Simultaneously, EPS
stimulates nitrogenase activity in type II methanotrophs
by creating oxygen-depleted zones. The kinetic results
were incorporated in a simulation model for gas
transport and methane oxidation in a passively aerated
biofilter.
Comparison between the model and experimental data
showed that, besides acting as a micro-scale diffusion
barrier, EPS can act as a barrier to macro-scale
diffusion, reducing the performance of such biofilters.
Sumber:
http://www.ncbi.nlm.nih.gov/pubmed/14987816 ….. Diunduh 28/4/2012
Waste Manag. 2004;24(7):643-53.
Long-term behavior of passively aerated compost methanotrophic biofilter
columns.
Wilshusen JH, Hettiaratchi JP, Stein VB.
The methane oxidation potential of several types of compost
methanotrophic biofilter columns were compared in the laboratory
over a period of 220 days.
The results indicate an increase in methanotrophic activity over a
period of about 100 days, up to a maximum of 400 g m(-2) day(-1),
and a gradual decline to about 100 g m(-2) day(-1) within the next
120 days.
High methane oxidation rates appear to be restricted to a
small area of the column, 10-15 cm thick. Based on the
laboratory investigations carried out to determine the
cause for the decline in methane oxidation rate, it was
concluded that the formation of exopolymeric substances
(EPS), at the zones of maximum methane oxidation, was
responsible for this decline.
In monitoring methane oxidation in a column for up to 600
days, it was observed that mixing of the medium after
formation of EPS enabled the column to temporarily
recover high performance.
The results suggest that stable, homogenous compost,
with a low C/N and low ammonium content, mixed on a
regular basis, could achieve and maintain high methane
oxidation efficiencies.
Sumber:
http://www.ncbi.nlm.nih.gov/pubmed/15288296 ….. Diunduh 28/4/2012
Waste Manag Res. 2009 Aug;27(5):409-55. Epub 2009 Jul 7.
Microbial methane oxidation processes and technologies for mitigation of
landfill gas emissions.
Scheutz C, Kjeldsen P, Bogner JE, De Visscher A, Gebert J, Hilger HA, HuberHumer M, Spokas K
Landfill gas containing methane is produced by anaerobic
degradation of organic waste. Methane is a strong greenhouse
gas and landfills are one of the major anthropogenic sources of
atmospheric methane.
Landfill methane may be oxidized by methanotrophic
microorganisms in soils or waste materials utilizing oxygen that
diffuses into the cover layer from the atmosphere.
The methane oxidation process, which is
governed by several environmental factors, can
be exploited in engineered systems developed
for methane emission mitigation.
Mathematical models that account for
methane oxidation can be used to predict
methane emissions from landfills.
Additional research and technology
development is needed before methane
mitigation technologies utilizing microbial
methane oxidation processes can become
commercially viable and widely deployed.
Sumber:
http://www.ncbi.nlm.nih.gov/pubmed/19584243….. Diunduh 28/4/2012
Waste Manag Res. 2008 Feb;26(1):33-46.
Biotic systems to mitigate landfill methane emissions.
Huber-Humer M, Gebert J, Hilger H
Landfill gases produced during biological degradation of buried organic wastes
include methane, which when released to the atmosphere, can contribute to
global climate change. Increasing use of gas collection systems has reduced
the risk of escaping methane emissions entering the atmosphere, but gas
capture is not 100% efficient, and further, there are still many instances when
gas collection systems are not used.
Biotic methane mitigation systems exploit the propensity of some naturally
occurring bacteria to oxidize methane.
By providing optimum conditions for microbial habitation and efficiently routing
landfill gases to where they are cultivated, a number of bio-based systems,
such as interim or long-term biocovers, passively or actively vented biofilters,
biowindows and daily-used biotarps, have been developed that can alone, or
with gas collection, mitigate landfill methane emissions
This paper reviews the science that guides
bio-based designs; summarizes
experiences with the diverse natural or
engineered substrates used in such
systems; describes some of the studies and
field trials being used to evaluate them; and
discusses how they can be used for better
landfill operation, capping, and aftercare.
Sumber:
http://www.ncbi.nlm.nih.gov/pubmed/18338700 ….. Diunduh 28/4/2012
Environ Pollut. 2004 May;129(2):305-14.
Methane oxidation and formation of EPS in compost: effect of oxygen
concentration.
Wilshusen JH, Hettiaratchi JP, De Visscher A, Saint-Fort R
Oxygen concentration plays an important role in the regulation of methane
oxidation and the microbial ecology of methanotrophs. However, this effect is
still poorly quantified in soil and compost ecosystems.
The effect of oxygen on the formation of exopolymeric substances (EPS) is as
yet unknown. We studied the effect of oxygen on the evolution of
methanotrophic activity. At both high and low oxygen concentrations, peak
activity was observed twice within a period of 6 months.
Phospholipid fatty acid analysis showed that there was a
shift from type I to type II methanotrophs during this period.
At high oxygen concentration, EPS production was about
250% of the amount at low oxygen concentration.
It is hypothesized that EPS serves as a carbon cycling
mechanism for type I methanotrophs when inorganic
nitrogen is limiting.
Simultaneously, EPS stimulates nitrogenase activity in type II
methanotrophs by creating oxygen-depleted zones. The
kinetic results were incorporated in a simulation model for
gas transport and methane oxidation in a passively aerated
biofilter.
Comparison between the model and experimental data
showed that, besides acting as a micro-scale diffusion
barrier, EPS can act as a barrier to macro-scale diffusion,
reducing the performance of such biofilters.
Sumber:
http://www.ncbi.nlm.nih.gov/pubmed/14987816 ….. Diunduh 28/4/2012
Waste Manag. 2004;24(7):643-53.
Long-term behavior of passively aerated compost methanotrophic biofilter
columns.
Wilshusen JH, Hettiaratchi JP, Stein VB
The methane oxidation potential of several types of compost
methanotrophic biofilter columns were compared in the laboratory
over a period of 220 days.
The results indicate an increase in methanotrophic activity over a
period of about 100 days, up to a maximum of 400 g m(-2) day(-1),
and a gradual decline to about 100 g m(-2) day(-1) within the next
120 days.
High methane oxidation rates appear to be restricted to a small area
of the column, 10-15 cm thick.
Based on the laboratory investigations carried out to
determine the cause for the decline in methane oxidation rate,
it was concluded that the formation of exopolymeric
substances (EPS), at the zones of maximum methane
oxidation, was responsible for this decline.
In monitoring methane oxidation in a column for up to 600
days, it was observed that mixing of the medium after
formation of EPS enabled the column to temporarily recover
high performance.
The results suggest that stable, homogenous compost, with a
low C/N and low ammonium content, mixed on a regular
basis, could achieve and maintain high methane oxidation
efficiencies.
Sumber:
http://www.ncbi.nlm.nih.gov/pubmed/15288296….. Diunduh 28/4/2012
DECOMPOSITION
•
•
•
Many organisms are very beneficial in ecosystems as decomposers.
Breakdown of organic matter recycles nutrients
Decomposition = important for recycling of C and energy, as well as all
nutrient elements (N, P, K, etc.).
Biological activity diminishes if the compost mix contains too
much carbon in relation to nitrogen. Several cycles of
organisms are required to burn excess carbon. This is a
complex chemical process. When organisms die, their
stored nitrogen and carbon become available to other
organisms. These new organisms form new cells which
again need nitrogen to burn excess carbon and produce
CO2. Thus, the amount of carbon is reduced and the limited
amount of nitrogen is recycled. Finally, when the ratio of
available carbon to available nitrogen is low enough,
nitrogen is released as ammonia. Under favorable
conditions, some ammonia may oxidize to nitrates.
Phosphorus, potash, and various micronutrients are also
essential for biological growth. These are normally present in
more than adequate amounts in compostable materials.
Mesophylic bacteria thrive from 70° to 90° F, but just survive at
temperatures above and below (40° to 70° F, and 90° to 110° F) In many
backyard piles, these mid range bacteria do most of the work. However, if
conditions are right, they produce enough heat to activate the
“thermophilic,” or heat loving bacteria. Thermophilic bacteria work fast.
Their optimum temperature range is from 104° to 160° F.
High temperatures destroy pathogenic bacteria and protozoa
(microscopic one celled animals), and weed seeds, which are detrimental
to health and agriculture when the final compost is used on the land.
Sumber: http://whatcom.wsu.edu/ag/compost/fundamentals/biology_aerobic.htm …
diunduh 21/4/2012
TIPE-TIPE DEKOMPOSISI
•
•
•
Proses Abiotik - fire, etc.
OM + O2  CO2, etc.
Proses Biotik:
– Aerobic respiration
OM + O2  CO2, etc.
– Anaerobic respiration
OM  CH4, etc.
Mikroba yang bertanggung-jawab langsung untuyk dekomposisi
bahan organik adalah bacteria dan fungi.
Organic material decomposing with oxygen is an "aerobic" process. When
living organisms that use oxygen feed upon organic matter, they develop cell
protoplasm from the nitrogen, phosphorus, some of the carbon, and other
required nutrients. Carbon serves as a source of energy for organisms and is
burned up and respired as carbon dioxide (CO2). Since carbon serves both as
a source of energy and as an element in the cell protoplasm, much more
carbon than nitrogen is needed. Generally, organisms respire about two-thirds
of the carbon they consume as CO2, while the other third is combined with
nitrogen in the living cells.
Biological activity diminishes if the compost mix contains too much
carbon in relation to nitrogen. Several cycles of organisms are required
to burn excess carbon. This is a complex chemical process. When
organisms die, their stored nitrogen and carbon become available to
other organisms. These new organisms form new cells which again
need nitrogen to burn excess carbon and produce CO2. Thus, the
amount of carbon is reduced and the limited amount of nitrogen is
recycled.
Finally, when the ratio of available carbon to available nitrogen is low
enough, nitrogen is released as ammonia. Under favorable conditions,
some ammonia may oxidize to nitrates. Phosphorus, potash, and
various micronutrients are also essential for biological growth. These
are normally present in more than adequate amounts in compostable
materials.
Sumber: http://whatcom.wsu.edu/ag/compost/fundamentals/biology_aerobic.htm … diunduh
21/4/2012
LAJU DEKOMPOSISI
•
Decomposition rates vary (measured in litter bags), depending on:
– Climate and temperature
– Soil organisms present
– Aeration of the soil
– Composition of the material (C:N ratio)
– Etc.– season, tillage
PENTINGNYA C/N RATIO
Microorganisms that digest compost need about 30 parts of carbon for every part of
nitrogen they consume. That's a balanced diet for them. If there's too much nitrogen,
the microorganisms can't use it all and the excess is lost in the form of smelly
ammonia gas. Nitrogen loss due to excess nitrogen in the pile (a low C:N ratio) can
be over 60%. At a C:N ratio of 30 or 35 to 1, only one half of one percent of the
nitrogen will be lost. That's why you don't want too much nitrogen (fresh manure, for
example) in your compost: the nitrogen will be lost in the air in the form of ammonia
gas, and nitrogen is too valuable for plants to allow it to escape into the atmosphere.
1.
2.
3.
4.
The four conditions that are constant for all residue decomposition:
A maximum of 35% of the carbon in fresh organic material will be converted into
soil humus IF there is sufficient nitrogen present.
A minimum of 65% of the carbon in fresh organic material will be given off to the
atmosphere as carbon dioxide due to microbial respiration. (Uh-oh! An argument
could be made that composting contributes to greenhouse gases and warming
of the Earth's atmosphere. However, consider this, nature is always
decomposing everywhere; so, what you are doing in your little compost bin is a
mere iota of carbon release compared to nature's vast compost bin in forests,
rangeland, etc.)
The humus formed from the decomposition of fresh organic material will contain
approximately 50% carbon and 5% nitrogen. In other words, the C:N ratio of the
humus is 10:1.
Most fresh plant material contains 40% carbon. The C:N ratio varies because of
differences in nitrogen content, not carbon content. (Note: Dry materials are
generally in the range of 40 to 50 percent carbon, and sloppy, wet materials are
generally 10 to 20 percent carbon. Therefore, the most important factor in
estimating the carbon-to-nitrogen ratio of plant or food waste is how much water
is present).
Sumber: http://www.homecompostingmadeeasy.com/carbonnitrogenratio.html … diunduh
21/4/2012
LAJU DEKOMPOSISI
•
Laju dekomposisi sangat beragam, tergantung pada:
– Iklim dan temperature
Temperature mempengaruhi laju dekomposisi
Sedikit bahan organik di daerah iklim panas
–
–
–
–
Organisme tanah yang ada
Aerasi tanah
Composition of the material (C:N ratio)
Kondisi musim, pengolahan tanah, dll
Temperature plays a huge role on the speed an item decomposes. The higher
the temperature in an area, the faster an object in that area will decompose.
Heat makes objects decompose more rapidly than they would if they were in a
cooler temperature. In the decomposition process, bacteria will eat compost,
which will then cause it to slowly disintegrate. When the atmosphere is cooler,
the air will kill the bacteria, which would then slow down the process of
decomposition. This happens because when the bacteria is weaker, the
decomposition of the object will not happen as fast.
When carbon is oxidized to CO2, a great deal of energy is released as heat.
For example, if a gram of glucose molecules is dissimilated under aerobic
conditions, 484 to 674 kilogram calories (kcal) of heat may be released. If
organic material is in a large enough pile or arranged to provide some
insulation, temperatures during decomposition may rise to over 170° F. At
temperatures above 160° F, however, the bacterial activity decreases.
There are many different kinds of bacteria at work in the compost pile. Each
type needs specific conditions and the right kind of organic material. Some
bacteria can even decompose organic material at temperatures below
freezing. These are called psychrophilic bacteria, and although they work
best at around 55°, they continue to work down to 0° F. As they work, they
give off small amounts of heat. If conditions are right, this heat will be
enough to set the stage for the next group of bacteria, the “mesophylic,” or
middle range temperature bacteria.
Sumber: http://whatcom.wsu.edu/ag/compost/fundamentals/biology_aerobic.htm …
diunduh 26/4/2012
LAJU DEKOMPOSISI
•
•
•
Decomposition rates vary (measured in litter bags),
depending on:
– Climate and temperature
– Soil organisms present
– Aeration of the soil
– Composition of the material (C:N ratio)
– Etc.– season, tillage
Season: spring = fresh green material; fall = tough residues
Tillage: aerates soil
PENTINGNYA C/N RATIO
For microorganisms, carbon is the basic building block of life and is a source of
energy, but nitrogen is also necessary for such things as proteins, genetic
material, and cell structure.
Balance of C:N is Key
Decomposition of organic materials in your compost pile is greatly increased
when you create the proper balance between the carbonaceous materials
(called BROWN because they are dry) and the nitrogen-rich materials (called
GREEN because they are more fresh and moist).
In compost , this balance is referred to as the Carbon-Nitrogen ratio, and
shown as C:N.
For best performance, the compost pile, or more to the point the composting
microorganisms, require the correct proportion of Carbon for energy and
Nitrogen for protein production. Compost scientists have determined that the
fastest way to produce fertile, sweet-smelling compost is to maintain a C:N
ratio somewhere around 25 to 30 parts Carbon to 1 part Nitrogen, or 25-30:1. If
the C:N ratio is too high (excess Carbon), decomposition slows down. If the
C:N ratio is too low (excess nitrogen) you will end up with a stinky pile.
Sumber: http://www.homecompostingmadeeasy.com/carbonnitrogenratio.html …
diunduh 21/4/2012
C:N ratio
•
•
Slower decomposition if C:N ratio is high.
Examples of C:N ratios…..
All organic matter is made up of substantial amounts of carbon
(C) combined with lesser amounts of nitrogen (N). The balance of
these two elements in an organism is called the carbon-tonitrogen ratio (C:N ratio).
For best performance, the compost pile, or more to the point the
composting microorganisms, require the correct proportion of
carbon for energy and nitrogen for protein production. Scientists
(yes, there are compost scientists) have determined that the
fastest way to produce fertile, sweet-smelling compost is to
maintain a C:N ratio somewhere around 25 to 30 parts carbon to
1 part nitrogen, or 25-30:1. If the C:N ratio is too high (excess
carbon), decomposition slows down. If the C:N ratio is too low
(excess nitrogen) you will end up with a stinky pile.
Below are the average C:N ratios for some common organic
materials found in the compost bin. For our purposes, the
materials containing high amounts of carbon are considered
"browns," and materials containing high amounts of nitrogen are
considered "greens."
Sumber: http://www.composting101.com/c-n-ratio.html … diunduh 21/4/2012
C:N Ratios BEBERAPA MACAM MATERIAL
PENTINGNYA C:N RATIO
•
•
With residues of high C:N, there is much competition
for the limited N available.
If C:N ratio is high:
– only some organisms can decompose (some
types of bacteria and fungi, protozoan symbionts
of termites).
– they use up N quickly, so N becomes tied up and
unavailable (immobilized).
High C:N Ratios
The carbon to nitrogen ratio of soil is about 10:1. When solid manure
or other organic material has a C:N ratio of greater than 30:1, there
is a higher risk that the soil bugs will "steal" nitrogen from the soil
and tie it up. Therefore this nitrogen is unavailable to a crop while
breaking down the carbon material. A crop with higher nitrogen
requirements, such as corn or wheat, will show nitrogen deficiencies
in that situation. When a material has a C:N ratio less than 20:1,
there is generally enough nitrogen in the organic
Material
C:N Ratio Range
Soil Microbes
4:1 to 9:1
Soil Organic Matter
10:1 to 12:1
Solid Cattle Manure
20:1 (light bedding) to
40:1 (heavy bedding)
Horse Manure
27:1 (straw bedding)
60:1 (sawdust bedding)
Solid Poultry Manure
5:1 layers
10:1 broilers and turkeys
Liquid Hog Manure
< 8:1
Liquid Dairy
15:1
Legume Residues
20:1 to 30:1
Corn Stalks
80:1
Wheat Straw
80:1
Sawdust
500:1
Pulp & Paper biosolids
25:1 (nitrogen added during process) to
200:1 (little or no nitrogen added)
Sumber: http://www.omafra.gov.on.ca/english/crops/field/news/croptalk/2010/ct1110a7.htm … diunduh 21/4/2012
PENTINGNYA C:N RATIO
Organic N
Bacteria
free up N
Inorganic N
Mineralization
Immobilization
Bacteria take scarce N
for themselves !
. Nitrogen Deficiency and Carbon:Nitrogen Ratios of Organic
Ammendments
"Carbon to nitrogen ratio inbalance" is a term used to describe a type of
nitrogen deficiency. Farmers from my grandfather's generation called it "sour
soil".
A field recently had pulp and paper biosolids applied. The newly planted crop
looked great, until the seedlings ran out of seed reserves and started utilizing
soil nutrients. The crop then turned a neon shade of yellow. What happened?
Organic-N & Ammonium-N
When an organic amendment is applied to a field, it adds nutrients and organic
matter to the soil. The organic matter contains about 60 percent organic
carbon. The carbon:nitrogen (C:N) ratio shows the proportion of organic carbon
to total nitrogen of a manure or organic material.
Nitrogen is a food source for the micro-organisms ("soil bugs") while they break
down organic carbon. The nitrogen can come from the added organic material
or it can come from the soil. During the process of carbon breakdown soil
microbes die and decompose. The microbial nitrogen is then returned to the
soil and becomes available to the plants. This adds to the organic nitrogen pool
within the soil along with the added organic material. How long the carbon
breakdown process takes depends on the ratio of carbon to nitrogen in the
material and in the soil.
Sumber: http://www.omafra.gov.on.ca/english/crops/field/news/croptalk/2010/ct1110a7.htm … diunduh 21/4/2012
PENAMBAHAN N-ORGANIK KE TANAH
Organic N
materials
decompose,
release nitrate
Adding organic N to soil
Nitrate used
in
decompositio
n process by
bacteria, etc.
Organic N
materials
decompo
se,
release
nitrate
PENAMBAHAN N-ORGANIK KE TANAH
BAHAN YANG MEMPUNYAI C/N RASIO RENDAH
Decompositi
on and
release of
nitrate is
fast, levels
recover
quickly
Adding organic N to soil
High C:N ratio material
Nitrate
release
difficult,
tied up for a
long time
N rob = immobility of N in presence of residues with high
C:N ratios
Nitrate
release
difficult,
tied up
for a long
time
Risky Mix of High and Low C:N
High C:N residue + Inorganic N fertilizer =
N from fertilizer immobilized by bacteria
BAGAIMANA MENGGUNAKAN C:N RATIO
Principle 1:
Ratio yang ideal 30:1
A hot, fast pile (with temperatures up to 140°F/60°C) is obtained when the C:N
ratio of all the materials you add averages 30:1 (50:1 is adequate for most
slower, lower-temperature piles). You can be sure, then, that the little microbes
are stuffing themselves.
This ratio describes the chemical composition of a material and does not
mean that you need a volume of brown materials that is thirty times greater
than the amount of green matter.
Graphic courtesy of University of Missouri Extension Service
Sumber: http://www.homecompostingmadeeasy.com/carbonnitrogenratio.html …
diunduh 21/4/2012
PENTINGNYA C:N RATIO
•
•
As C:N ratio goes lower (as it does during
decomposition), more organisms (especially fungi,
different bacteria types, even some insects) can join in, so
decomposition proceeds much faster.
Most insects and other animals join later in the process,
as the C:N ratio of their food is low:
– e.g., fungi 10:1, decomposed animals 6:1, nematodes
10:1.
Principle 2:
Dua bagian hijau dan satu bagian
coklat
(The best stragey to mix your compostable materials)
Generally speaking, you can get C:N ratios of 30:1 to 50:1 by
adding two parts of a GREEN material to one part of a
BROWN material to your bin.
A "part" can be defined as a certain quantity of the
material, such as two 5-gallon buckets of GREEN and 1
packed bucket of BROWN.
For example, food scraps, grass clippings and leaves come
close to an average of 30:1. How? Add-up the Carbon side of
the ratio for all three materials, i.e. 15, 17, 60, and divide by
the number of materials, i.e. three. 92/3 = about 31:1.
Sumber:
… diunduh 21/4/2012
PENGOMPOSAN = COMPOSTING
•
•
•
•
•
Mempercepat proses dekomposisi bahan organik
Mereduksi (menurunkan) C:N ratio
Suhu tinggi: 60-80oC (140-175oF)
Bakteri Thermophilic
Banyak tersedia teknologinya
The best combination would be a mixture of
GREEN sources, as shown on the left of the chart
below and a BROWN source such as leaves
(notice that leaves have a fairly low C:N ratio
compared to other carbonaceous materials shown
on the right of the chart.
Leaves are ideal for composting.
Researchers have determined that effective
compost can be made with equal parts GREEN
and BROWN, or with 2 parts GREEN and 1 part
BROWN.
Sumber:
http://www.homecompostingmadeeasy.com/carbonnitrogenratio.html …
diunduh 21/4/2012
PENGOMPOSAN = COMPOSTING
Use this Rule of Thumb when viewing the chart below
Any organic matter that has a C:N ratio generally smaller than 30:1 is considered a GREEN.
Any organic matter that has a C:N ratio generally larger than 30:1 is considered a BROWN.
Common Home Compostable Materials & C:N Ratios
(Example: Food Scraps has a Carbon:Nitrogen Ratio of 17:1,
meaning 17 parts Carbon to 1 part Nitrogen)
GREEN (Nitrogen)
Aged Chicken Manure
7:1
Fresh manures are way to hot and can burn your
plants and roots!
BROWN (Carbon)
Leaves 60-80:1
One of the most important ingredients for
composting, especially shredded or broken down
(leaf mulch).
Food Scraps 17:1
Straw, Hay 90:1
Vegetable Scraps 25:1
The best way to use is to shred for faster
breakdown.
Sawdust 500:1
Coffee Grounds 25:1
Grass Clippings - Fresh 17:1
Commercially produced compost is high in
sawdust or shredded bark chips. Use very
sparingly!
Woody chips & twigs 700:1
Dry clippings would be higher in Carbon. Therefore,
Be sparing. Best use is small material at bottom
use as carbon source if necessary.
of bin or pile.
Fresh Weeds 20:1
Shredded Newspaper 175:1
Make sure you don't compost weeds with seeds,
unless you insure that your pile gets hot - over
140°F/60°C.
Fruit Wastes 25-40:1
Rotted Manure 20:1
Has no nutrient content. Best used in
vermicomposting. Always shred and soak in water
for fast breakdown.
Nut shells 35:1
Pine Needles 80:1
Horse manure should not be used because it
contains undigested seeds that can sprout in the bin.
Humus (soil) 10:1
Use sparingly. Very acidic and waxy; breaks
down slowly.
This is nature's natural ratio. Use sparingly in pile.
Best used to "seal" the pile by putting a 1-2 inch
layer on top.
Corn Stalks 60:1
Shred or cut up in small pieces for fast break
down.
Peat Moss 58:1
Seaweed 19:1
General Garden Waste 30:1
Clippings from plants, stalks, dead flowers, etc.
Excellent mix with leaves
Sumber:
Has no nutrient value. In the bin it is mostly filler.
NOTE
The C:N Ratios given in this chart are average
and may slightly vary according to source,
researcher or scientist!
http://www.homecompostingmadeeasy.com/carbonnitrogenratio.html…
RANGKAIAN PROSES DEKOMPOSISI
•
•
Organic
material
(litter)
Berlaku untuk bahan organik dari tumbuhan
Bahan organik dari hewan mempunyai nuilai C/N rendah,
mudah di-dekomposisi oleh hewan, dll.
soil animals
bacteria, fungi
   detritus    humus
(small particles)
soil chemistry
   mineralization
The composting process
The composting process involves four main components: organic matter, moisture, oxygen,
and bacteria.
Organic matter includes plant materials and some animal manures. Organic materials used
for compost should include a mixture of brown organic material (dead leaves, twigs, manure)
and green organic material (lawn clippings, fruit rinds, etc.). Brown materials supply carbon,
while green materials supply nitrogen. The best ratio is 1 part green to 1 part brown material.
Shredding, chopping or mowing these materials into smaller pieces will help speed the
composting process by increasing the surface area.
For piles that have mostly brown material (dead leaves), try adding a handful of commercial
10-10-10 fertilizer to supply nitrogen and speed the compost process.
Moisture is important to support the composting process. Compost should be comparable to
the wetness of a wrung-out sponge. If the pile is too dry, materials will decompose very
slowly. Add water during dry periods or when adding large amounts of brown organic
material. If the pile is too wet, turn the pile and mix the materials. Another option is to add
dry, brown organic materials.
Oxygen is needed to support the breakdown of plant material by bacteria. To supply oxygen,
you will need to turn the compost pile so that materials at the edges are brought to the
center of the pile. Turning the pile is important for complete composting and for controlling
odor.
Wait at least two weeks before turning the pile, to allow the center of the pile to "heat up"
and decompose. Once the pile has cooled in the center, decomposition of the materials has
taken place. Frequent turning will help speed the composting process.
Bacteria and other microorganisms are the real workers in the compost process. By
supplying organic materials, water, and oxygen, the already present bacteria will break down
the plant material into useful compost for the garden. As the bacteria decompose the
materials, they release heat, which is concentrated in the center of the pile.
You may also add layers of soil or finished compost to supply more bacteria and speed the
composting process. Commercial starters are available but should not be necessary for
compost piles that have a proper carbon to nitrogen ratio (1 part green organic material to 1
Sumber: http://urbanext.illinois.edu/compost/process.cfm … diunduh 21/4/2012
. Using Mortality Compost in Vegetable Production: A comparison between
summer and winter composting and its use in cabbage production
C. S. Dunkley, D. L. Cunningham, C. W. Ritz, K. D. Dunkley, A. Hinton
Agriculture, Food and analytical Bacteriology (AFAB).
Published 05/2011. volume 1 issue 1. Pp. 6-1
. A study was conducted to
determine the effectiveness of
composting to breakdown the
carcasses of daily poultry mortality
and in the process destroy
pathogenic microorganisms that may
be present.
The study was conducted during the summer and
repeated in the winter to determine whether the time
of year would affect the temperature profile or the
length of time required for the process to be
completed. Daily mortalities were collected from a
nearby producer and layered in a compost bin each
day for four days. Samples were collected from the
litter before it was placed in the bin. Compost
samples were collected every other day for a week
after the bin was compiled and then once per week
until the process was completed. The samples were
evaluated for microbial content. Temperature was
taken and recorded at random points in the bins on a
daily basis. Upon completion of the composting
process, the material was used as a soil amendment
in two vegetable plots while a third plot without
compost material served as the control. Soil samples
were collected from each of the plots prior to
application of the compost material. Cabbage
seedlings were then planted in each of the plots.
Vegetative samples and soil samples were collected
and evaluated for microbial presence prior to planting
and at week, 1, 3, 7, and again at reaping. The
summer compost had the highest temperature of
156°F on d 9 during the primary phase while the
winter compost had the highest temperature of 156°F
on d 42 during the secondary phase of the compost.
The summer compost samples were Salmonella
enterica (SE) negative from d 2 of the trial but mixed
bacterial colonies remained for the duration of the
study. The vegetative samples in plot 1 had coliform
levels of 3.48 log10/gm at wk10 but the levels was
not considered significantly different from the other
two plots (p<0.05).
The results show that while winter composting can effectively breakdown poultry
carcasses and attain high temperatures, summer compost is more efficient and had
consistently higher temperatures.
Sumber: http://afabjournal.com/articles/using-mortality-compost-in-vegetable-production-acomparison-between-summer-and-winter-composting-and-its-use-in-cabbage-production/ …..
The use of respiration indices in the composting process: a review
Raquel Barrena Gómez, Felicitas Vázquez Lima, Antoni Sánchez Ferrer
Waste Manag Res February 2006 vol. 24 no. 1 37-47
. Respiration is directly related to the metabolic
activity of a microbial population. Micro-organisms
respire at higher rates in the presence of large
amounts of bioavailable organic matter while
respiration rate is slower if this type of material is
scarce. In the composting process respiration
activity has become an important parameter for the
determination of the stability of compost. It is also
used for the monitoring of the composting process
and it is considered an important factor for the
estimation of the maturity of the material.
A wide range of
respirometric protocols has
been reported based either
on CO2 production, O2
uptake or release of heat.
The most common methods
are those based on O2
uptake.
Respirometric assays are
affected by a number of
parameters including
temperature, humidity, and
both incubation and preincubation conditions.
Results from respirometries are generally expressed as ‘respiration indices’,
most of them with their own units and basis. In consequence, some confusion
exists when referring and comparing respiration indices.
This is particularly important because current and future legislations define and
measure the biological stability of waste on the basis of respiration activity of
the material. This paper discusses and compares most common respiration
indices currently used.
Sumber: http://wmr.sagepub.com/content/24/1/37.refs ….. Diunduh 22/4/2012
. The influence of temperature and moisture contents regimes on the aerobic
microbial activity of a biosolids composting blend
C Liang, K.C Das, , , R.W McClendon
Bioresource Technology. Volume 86, Issue 2, January 2003, Pages 131–137
. To understand the relationships
between temperature, moisture
content, and microbial activity
during the composting of biosolids
(municipal wastewater treatment
sludge),
Well-controlled incubation
experiments were
conducted using a 2-factor
factorial design with six
temperatures (22, 29, 36,
43, 50, and 57 °C) and five
moisture contents (30, 40,
50, 60, and 70%). The
microbial activity was
measured as O2 uptake
rate (mg g−1 h−1) using a
computer controlled
respirometer. In this study,
moisture content proved to
be a dominant factor
impacting aerobic microbial
activity of the composting
blend
. Fifty percent moisture content appeared to be the minimal requirement for
obtaining activities greater than 1.0 mg g−1 h−1. Temperature was also
documented to be an important factor for biosolids composting. However, its
effect was less influential than moisture content. Particularly, the
enhancement of composting activities induced by temperature increment
could be realized by increasing moisture content alone.
Sumber:
http://www.sciencedirect.com/science/article/pii/S0960852402001530….. Diunduh
22/4/2012
. Microbial activity during composting of anthracene-contaminated soil
Y Ma, J.Y Zhang, M.H Wong
Chemosphere. Volume 52, Issue 9, September 2003, Pages 1505–1513
. Microbial activity of an anthracenespiked soil mixed with kitchen waste
during laboratory composting at 56–59
°C was studied using an in-vessel
technology.
The effect of old compost
containing acclimated
microorganisms on the
composting efficiency was
also investigated.
Microbial succession,
microbial enzyme activity,
microbial diversity and
anthracene removal rate
were analyzed during 42
days of composting.
The results demonstrated that inoculating with old compost increased the
amounts of thermophilic microorganisms, but did not significantly increase
anthracene removal.
A microbial succession from mesophilic bacteria to thermophilic bacteria
and thermophilic actinomycetes was observed during composting.
Polyphenol oxidase activity decreased while catalase activity varied
irregularly.
Microbial diversity increased drastically when temperature elevated from
35 to 56 °C, but decreased when temperature maintained at 56–59 °C.
Sumber:
http://www.sciencedirect.com/science/article/pii/S0045653503004892 ….. Diunduh
22/4/2012
Bioresour Technol. 2004 May;93(1):49-57.
Determination of aeration rate and kinetics of composting some
agricultural wastes.
Kulcu R, Yaldiz O.
This study aimed to determine the aeration rate and its
kinetics in aerobic composting of agricultural wastes. For
this aim compost materials were prepared by mixing grass
trimmings, tomato, pepper, and eggplant wastes. Four
vertical forced aeration type reactors and one vertical natural
convection type reactor were manufactured to apply four
different aeration rates. CO2 rate and temperature changes
were recorded in three different places in the reactors.
Moisture content, pH and organic material rate were
recorded each day. While process-monitoring parameters
(CO2, temperature, pH, moisture content) were used for
interpretation of the process, organic material degradation
was used for interpretation of the process success. The
seven different kinetic models were applied for modeling
decomposition rate to the experimental values. According to
the results, four of these models were found applicable to
this study. These models were analyzed with some
statistical methods as root mean square error (RMSE), chisquare (chi2), and modeling efficiency (EF). According to the
statistical results of these models, the best model was found
as: [Formula: see text] where kT is the rate of decomposition
(g VS/g VS day); T the process temperature (degrees C);
Mc the daily moisture content (%wb); C the daily CO2 rate in
composting reactor (%) and a, b, c, d are constants.
According to the results, the highest organic matter
degradation and temperature value were obtained at the
aeration rate of 0.4 l air min(-1)kg(om)(-1). Thus, it could be
applied to this mixed materials composting process.
Eucalyptus leaf-litter
decomposition:
Effects of relative
humidity and
substrate moisture
content
L.A. Nagy, B.J.
Macauley
Soil Biology and
Biochemistry. Volume
14, Issue 3, 1982,
Pages 233–236
A method to
determine the effect
of relative humidity
and substrate
moisture content on
rates of
decomposition of
Eucalyptus leaf litter
is described.
Significant loss of dry weight occurred at relative humidity and moisture
content values of 32 and 5% respectively which are values much lower than
those at which microbial activity in other systems has been reported.
It is likely, however, that biological decomposition is not significant until
relative humidity and moisture content values are above 75 and 13%
respectively.
Sumber:
http://www.sciencedirect.com/science/article/pii/0038071782900311….. Diunduh
22/4/2012
. Evaluation of Compost Maturity, Hydrophysical and Physicochemical
Properties: Indicators for Use as a Component of Growing Media
Compost Science & Utilization, (2011), Vol. 19, No. 3, 226-234
Manel Kammoun Rigane, Jean-Charles Michel, Khaled Medhioub and Philippe
Morel
The cocomposting of
agricultural waste is a new
management priority in
Tunisia.
In this study, four composts were
evaluated by comparing the changes in
measured hydrophysical and
physicochemical properties and
phytotoxicity. The organic wastes used
were almond shell (AS), sesame bark
(SB), olive husk (OH), and green and
wood wastes (GW and WW,
respectively). Composts CI and CII
were composed of AS/SB and OH/SB,
respectively, at a ratio of 75/25 (wet
weight basis). CIII consisted of OH, SB
and CAS (coarsely-ground almond shell
used as a bulking agent) at a ratio of
55/25/20. Finally, CIV was composed of
25%SB+9%CAS+18%GW+48%WW.
The composts studied were characterized by basic pH and an electric conductivity (EC)
value ranging from 1.6 to 2.4 mS/cm. The organic matter contents (OM) and C/N ratios
of composts ranged from 20 to 46% and from 10 to 21%, respectively. Based on
hydrophysical analyses, composts CI, CIII and CIV, containing AS, were shown to have
a porosity and a water content of 10-26% and 10-20%, respectively. The phytotoxicity of
composts was studied on the basis of cress seed germination.
Results revealed that differences in properties are mainly related to the
nature of composted waste and that some of these composts are
compatible for use as constituents in growing media for horticultural
soilless cultures.
Sumber:
http://www.jgpress.com/compostscience/archives/_free/002502.html….. Diunduh
22/4/2012
. Emission of Carbon Monoxide During Composting of Municipal Solid Waste
Compost Science & Utilization, (2011), Vol. 19, No. 3, 170-177
E.A. Phillip , O.G. Clark , K. Londry , S. Yu and J. Leonard
Elevated concentrations of carbon
monoxide (CO) have been observed
at the enclosed municipal waste
composting facility (ECF) in Edmonton,
Canada. Elevated concentrations of
CO in an enclosed facility pose a
potential health risk to workers.
The objectives in this study were to:
(1) assess temporal and spatial
variability of CO emissions from the
composting bays in the ECF using
Fourier Transform Infrared (FTIR)
spectroscopy; and (2) identify any
correlations between the CO
emission rate and the
physicochemical properties of the
compost through bench-scale
incubation experiments. Repeated
gas measurements were taken
above and within the compost bed in
the ECF using a probe connected to
an FTIR gas analyzer, which
continuously collected concentration
data.
These preliminary field measurements showed maximum CO concentrations of 112 µL
L-1 within the compost. Autoclaved and non-sterilized compost samples from the ECF
were incubated under aerobic and hypoxic conditions, and gas emissions were
quantified using gas chromatography (GC).
These trials showed a positive correlation between CO emission rate and incubation
temperature for all samples, indicating a physico-chemical source of CO generation.
Lower concentrations of CO were observed in the non-sterilized compost under both
aerobic and anaerobic conditions, presumably due to the microbial metabolism of CO.
Sumber:
http://www.jgpress.com/compostscience/archives/_free/002491.html….. Diunduh
22/4/2012
. Composting Wet Olive Husks with a Starter Based on Oil-Depleted Husks
Enhances Compost Humification
Compost Science & Utilization, (2011), Vol. 19, No. 3, 182-188
M.C. Echeverria, R. Cardelli, S. Bedini, M. Agnolucci, C. Cristani, A. Saviozzi and M.
Nuti
Wet olive husks represent an
environmental problem in
Mediterranean areas but also a
potential resource as recyclable
organic matter.
In the present work, we
describe the composting
of wet olive husks, using
mechanically turned
piles without forced
ventilation, carried out to
study the effects of
partially composted oildepleted husks as a
starter for wet husks
degradation.
At the beginning of the composting process, protease and dehydrogenase
activity, along with the microbial respiration, were higher in the piles with
the starter, demonstrating a higher microbial activity in comparison with
the piles without the starter.
At the end of the process, the compost with the starter showed a deeper
humification and a lower content of total organic carbon with respect to the
compost without the starter, indicating a higher level of biodegradation and
organic matter evolution.
The main outcome of this research includes the possibility to: (a) detoxify
and de-odorize a bad-smelling waste into an hygienically safe product; (b)
produce a green, mature, humified compost useful to restore soil fertility
and texture in intensive and organic agriculture.
Sumber:
http://www.jgpress.com/compostscience/archives/_free/002489.html….. Diunduh
22/4/2012
Growth of Tomato and Zucchini Seedlings in Orange Waste Compost Media:
pH and Implication of Dosage
Compost Science & Utilization, (2011), Vol. 19, No. 3, 189-196
Agostino Sorgonà, Maria Rosa Abenavoli, Giovanni Cacco and Antonio Gelsomino
The high pH and electrical
conductivity values of mature
compost from solid wastes of
citrus processing plants can
severely restrict its use as a
constituent of growing media in
soilless cultivation.
In the present work, addition of
phosphoric acid was used as a
chemically feasible strategy to
lower the pH of mature orange
waste compost. The growing
media for testing were
prepared by mixing commercial
perlite (Agrilit®3) with
increasing dosages (0, 7.5, 15
and 30%, by vol) of orange
waste compost after a pH
adjustement to 6.5-6.7 with the
addition of phosphoric acid.
In all potting mixtures the electrical conductivity never exceeded 0.7 dS m-1. Plant
growth responses (i.e. fresh and dry biomass, together with root morphological
parameters such as root length, surface area, fineness and tissue density) were
assessed on tomato and zucchini seedlings grown in potting mixtures under greenhouse
conditions for 40 and 20 days, respectively.
The results indicated that orange waste compost induced species-specific and dosedependent responses on plant growth. The growing rates were generally higher in
zucchini than in tomato seedlings; moreover, amendments larger than 7.5% determined
a reduced growth rate in both plants which became more evident at 30% compost
doses.
The same responses were induced on root morphological parameters: larger increases
in root length, surface area, root dry weight, fineness and tissue density were observed
in zucchini than in tomato; moreover, in both plants optimal morphological responses
were found at 7.5% compost dose. Overall the results indicated that phosphoric acid
may efficiently be used to control high pH values in orange waste compost and make it
suitable for wider use as a constituent of perlite-rich media provided the amendment
rates are carefully evaluated.
Sumber:
http://www.jgpress.com/compostscience/archives/_free/002488.html ….. Diunduh
22/4/2012
Adsorption of Phosphate by Goethite and Zeolite: Effects of Humic Substances
from Green Waste Compost
Compost Science & Utilization, (2011), Vol. 19, No. 3, 197-204
Zhimang Gu, Fatih Büyüksönmez, Shashikanth Gajaraj and R. Edward Beighley
Compost is widely used as a natural soil
conditioner and fertilizer supplement in
gardening, planting and agriculture. Ability of
compost to retain and release nutrients over
time offers potential use for control of excessive
nutrient release to the environment; this ability
may be further improved by the addition of
adsorbents to facilitate rapid retention of
nutrients.
Therefore, we investigated the
effects of humic substances
extracted from green waste
compost on the adsorption of
phosphate by goethite (aFeOOH) and zeolite
(SiO2.Al2O3). Humic acid
(4.66% by dry-weight) and
fulvic acid (1.26% as
carbon/w) were extracted from
finished compost and purified.
The adsorption capacity of goethite (1.18 mmol/g) was slightly higher than
zeolite’s capacity (1.03 mmol/g). On the other hand, capacity of humic
acid was determined much lower (0.51 mmol/g).
The addition of fulvic acid resulted in a substantial reduction of adsorption
capacities of all three adsorbents. Addition of 5.0 mmol/L of fulvic acid (as
carbon) decreased the adsorption capacity of phosphate by goethite,
zeolite and humic acid by 94%, 88% and 82%, respectively.
Results of kinetics study indicated that the adsorption data fit the firstorder kinetic model well with goethite exhibiting higher kinetic constants.
The results of this study suggest that metal oxide adsorbents such as
goethite could be applied as additives into compost to improve the nutrient
holding ability.
Sumber:
http://www.jgpress.com/compostscience/archives/_free/002487.html ….. Diunduh
22/4/2012
Trace Metals in Municipal Solid Waste Compost: Sources and Research
Methodology
Compost Science & Utilization, (2011), Vol. 19, No. 2, 79-86
Shouhai Yu , Daryl M. McCartney , Weixing Chen , Lixian Zhou and Salim Abboud
A concern regarding MSW
compost quality is the trace
metal content.
A study was initiated to assess the
impact of various metal contaminants
on compost quality. One critical step in
the study was to estimate metal
transfer during composting, which was
achieved by measuring the corrosion
rate of different contaminants during
the high rate composting stage for 3
weeks using alfalfa hay and straw as
composting substrate. A corrosion
quantification technique, weight
loss/gain of metal specimens, was
employed to estimate metal release
into composting substrate.
Among the 7 types of contaminants, stainless steel screws, brass screws,
and light bulb aluminum alloy thread contacts showed little weight
changes. This suggests minimum concerns for these materials in terms of
metal release during composting. The highest metal release per unit area
was from light bulb foot contacts, which was 3.66210-3 g cm-2, while
galvanized steel nails and zinc plated screw had a metal release rate in
the range of 1.5 to 1.9210-3 g cm-2.
Scanning Electron Microscope (SEM) was employed to determine the
chemistry of corrosion products and change of surface morphology by
corrosion and X-ray diffraction/spectrum to determine the type of
corrosion products formed on the surface of some selected samples. As
there is little literature on this subject, methodology and data from this
work can be served as a scientifically sound reference to academics,
industry and legislators.
Sumber:
http://www.jgpress.com/compostscience/archive.html ….. Diunduh 22/4/2012
Changes in Soil Properties and Carbon Content Following Compost
Application: Results of On-farm Sampling
Compost Science & Utilization, (2011), Vol. 19, No. 2, 87-96
Sally Brown and Matt Cotton
A field survey was conducted
to quantify the benefits of
applying compost to
agricultural soils in California.
Soil samples were collected from
farm sites with a history of compost
use. Soils were analyzed for total
organic carbon and nitrogen,
Mehlich III extractable nutrients,
bulk density, microbial activity
(measured as CO2 evolution),
water infiltration rate and
gravimetric water at 1 bar tension.
Across all sites, compost application increased soil organic carbon by 3x
in comparison to control soils. Significant changes were also observed in
soil microbial activity (2.23 x control), gravimetric water (1.57 x control),
and bulk density (0.87 x control). Nutrient availability in compost
amended soils was similar to availability in conventionally managed soils.
Infiltration times were significantly reduced in compost amended soils in
comparison to control soils.
High rates of compost application showed more significant benefits in
comparison to low rates of compost application and control soils. At lower
application rates, compost amended soils were statistically similar to
controls for most variables. Increases in water holding capacity were
significant in coarser textured soils in comparison to finer textured soils.
Results from this sampling confirm results from replicated field trials on
benefits associated with compost use in agricultural soils.
Sumber:
http://www.jgpress.com/compostscience/archives/_free/002356.html ….. Diunduh
22/4/2012
Use of Avoidance Tests for Investigating Potential of the Earthworm Eisenia
fetida to Improve Composting of Grass Clippings
Compost Science & Utilization, (2011), Vol. 19, No. 2, 123-128
Paul Illmer and Martin Liebensteiner
The earthworm Eisenia fetida
is the most commonly used
worm for worm-supported
composting of organic residues.
Within the present study, the
potential of E. fetida for
decomposing grass clippings, an
organic waste which usually
causes anoxic conditions and thus
insufficient degradation in the
course of common composting,
was investigated. To enable a
thorough investigation, the
substrate-related requirements of
E. fetida were studied using socalled avoidance tests. These tests
provide a sensitive method for
evaluating the preferences and
aversions of soil animals related to
substrate ingredients in a sublethal
range.
E. fetida favored relatively moist soil with about 70% of the WHCmax and the most
preferred concentration of fresh grass clippings within soil was 15% (v/v).
Pretreatments of the grass clippings like silage, precomposting or inoculation with the
fungi Trichoderma viride and Geotrichum klebahnii were investigated and point to an
increased tolerance of the worms against pre-composted and inoculated grass whereas
ensiled grass and remoistened hay was avoided.
The optimum concentration of ammonium for E. fetida was 18 µg NH4+-N g-1 DW soil
although the worms could withstand much higher concentrations. Lactic and acetic
acid, intermediates that are quickly released from fresh lawn clippings under oxygen
lacking conditions, were indicated to be the most important factors for preventing
worms from tolerating higher concentrations of grass clippings.
Sumber:
http://www.jgpress.com/compostscience/archives/_free/002352.html….. Diunduh
22/4/2012
Cocomposting of Olive Mill Wastewater with Manure and Agro-industrial
Wastes
Compost Science & Utilization, (2011), Vol. 19, No. 2, 129-134
Hafedh Rigane and Khaled Medhioub
The use of olive mill wastewater
(OMW) for composting was studied
by the addition of this liquid waste to a
mixture of olive husks, poultry manure
and confectionery wastewater. The
composting process was compared with
that of another pile of similar
composition, but without olive mill
wastewater.
In order to study the
effects of both composts
on plant yield and soil
properties, a field
experiment was carried
out with potato. Three
amendments were
applied: manure and two
composts with same rate
30 tonnes/ha.
The olive mill wastewater addition produced compost with higher organic matter
concentrations and higher electrical conductivity, and a stabilized and humified organic
matter lower than the compost produced without olive mill wastewater.
The olive mill wastewater compost application to soil did not injure plants, producing a
similar plant yield to both compost without olive mill wastewater and manure.
The olive mill wastewater compost application to soil also improved the chemical and
physicochemical properties of the soil mainly fertilizing elements such as calcium,
magnesium, nitrogen, potassium and phosphorus. With respect to potato yield, both
composts showed higher plant production in comparison to manure, reaching a potato
yield of 46 and 47 t/ha in amended soil with compost with and without OMW,
respectively.
Sumber:
http://www.jgpress.com/compostscience/archives/_free/002351.html ….. Diunduh
22/4/2012
Acceleration Effects of Microbial Inoculum on Palm Oil Mill Organic
Waste Composting
Compost Science & Utilization, (2011), Vol. 19, No. 2, 135-142
C.Y. Yeoh1, N.L. Chin , C.S. Tan and H.S. Ooi
The acceleration effects of
inoculum in composting of
empty fruit bunches were
investigated.
Composting of empty fruit bunches
fibres in two sizes, 4 cm and 2 cm
length, were treated with microbial
inoculum consisting of Agromonas,
Aspergillus, Azotobacter, Bacillus,
Cellulomonas, Chaetomium,
Clostridium, Coprinus, Microbispora,
Penicillium, Pseudomonas,
Thermoactinomyces, Trichoderma and
Trichurus in separate laboratory scale
in-vessel of 30 liters volume. A control
without inoculum with 4 cm length
empty fruit bunches was also conducted
in parallel. The compost piles were shiftturned weekly. Parameters such as
moisture content, temperature, pH, and
electrical conductivity were used to
monitor the composting processes. The
carbon-nitrogen ratio, UV-vis
spectrophotometer test, and
germination test were used to assess
the maturity of compost.
The results showed that the inoculum was effective in reducing the C/N ratio by 54%
compared to control 46% and rapidly increasing the UV-vis absorption ratio in first three
weeks.By using functional microbes, the composting of empty fruit bunches was reduced
to 5 weeks compared to 9 weeks for those without inoculation. The acceleration effect
was more prominent for the 2 cm length samples.
Sumber:
http://www.jgpress.com/compostscience/archives/_free/002350.html….. Diunduh
22/4/2012
HEAVY METAL REDUCTIONS IN SOILS AMENDED WITH COMPOST
AND WATER TREATMENT RESIDUALS
Compost Science & Utilization, (2011), Vol. 19, No. 1, 69-73
Esawy kasem Mahmoud
Remediation of heavy metal in
contaminated soils is necessary
in order to alleviate the potential
risks that they pose to both
environment and human health.
The present work was carried
out to evaluate the effect of
rice straw compost, water
treatment residuals (WTR),
and their mixture (2:1 and 1:1
wet weight), on heavy metal
immobilization in
contaminated soils and on
growth of canola (Brassica
napus).
The results showed that the Pb, Cd and Zn concentrations were
significantly reduced in the root and shoot of canola plant grown with the
application of rice straw compost and WTR amendment. Extractability of
the metals was also significantly reduced in this treatment compared with
the control.
The dry weight and root depth of canola plants were significantly
increased with the application WTR and compost treatments at two levels
10 or 20 mg kg -1 soil compared with the control. The addition of
compost and WTR (2:1 or 1:1 wet weight ratio) at 10 g dry weight kg-1
dry soil gave the best reduction in the soil metal extractability and in and
plant growth compared with other treatments.
Thus, the combination of rice straw compost and WTR was successful in
lowering the bioavailability of metals and increasing yield of canola grown
on the contaminated soil.
Sumber:
http://www.jgpress.com/compostscience/archives/_free/002339.html ….. Diunduh
22/4/2012
Evaluation of Nutrients Released from Phosphorus-Enriched Empty Oil Palm
Fruit Bunches As Growing Media Using Setaria splendida
Compost Science & Utilization, (2011), Vol. 19, No. 1, 61-68
D.T. Sabrina, M. M. Hanafi , T.M.M. Mahmud , and A.A. Nor Azwady
The use of oil palm empty fruit bunch,
an agricultural waste from oil palm
plantations, as a feeding material for
earthworms during composting provides
an alternative source of nutrients for
plants. Information regarding the ability of
earthworms in processing phosphorusenriched empty oil palm fruit bunch and
their effects on plants is still lacking.
The objective of this study
was to compare the effects of
phosphorus-enriched empty
oil palm fruit bunches applied
as fresh, composted or
vermicomposted media in
supplying nutrients on a test
crop, Setaria splendida L.,
grass planted on Bungor
(Typic Kandiudult) soil.
The soil treated with phosphorus-enriched vermicomposted empty oil palm fruit bunch
increased the grass dry matter yield significantly higher compared to that treated with
composted empty oil palm fruit bunch and control. The root volume of
vermicomposted- and composted- empty oil palm fruit bunches treated soil was
similar but significantly greater than the control. There was significant interaction
between dosage and type of growing media on cumulative N, P, K, Ca, and Mg
uptake. However, these factors did not show significant influence on total N, P, Ca and
Mg in the soil amended with composted oil palm empty fruit bunch at the end of the
experiment. In general, phosphorus-enriched vermicomposted- and phosphorusenriched composted- empty oil palm fruit bunches treated soil resulted in a greater
positive effect on growth and nutrient uptake of S. splendida, and also on the total
nutrient content in soil except for total K. Total soil K in the control treatment was
242.0 mg/kg and significantly higher compared to soil treated with composted- (173
mg/kg) and vermicomposted- empty oil palm fruit bunches (167 mg/kg). The
vermicomposted empty oil palm fruit bunch resulted in better growth performance of
the S. splendida in comparison to composted- and fresh- empty oil palm fruit bunches
due to the readily available P and other nutrients being readily available to the plants.
Sumber:
http://www.jgpress.com/compostscience/archives/_free/002340.html ….. Diunduh
22/4/2012
The Influence of Outdoor Windrow Composting On the Concentration of
Grayanotoxins in Rhododendron Leaves
Compost Science & Utilization, (2011), Vol. 19, No. 1, 44-51
David Michie , Audrey Litterick and Colin Crews
This work aimed to determine
whether composting reduced
concentrations of plant toxins
(grayanotoxins) present in
rhododendron leaves.
Bags of shredded R. ponticum
leaves and twigs were buried in a
commercial compost windrow
during a 12-week composting
process. Samples of R. ponticum
tissue were tested for toxic
grayanotoxins prior to the
composting process. Further
samples were removed eight times
during the process and were
analysed for grayanotoxins.
Grayanotoxins-I and III were
present in the R. ponticum material
prior to composting, but were found
to degrade during the composting
process and were not detected in
samples removed for testing 11
weeks after the start of
composting.
Similar degradation was not recorded in R. ponticum material stored
outside at ambient temperatures. Degradation of the grayanotoxins present
in rhododendron is likely to occur during composting, and the amount of
rhododendron material present in typical green waste compost windrows is
likely to be low. For these reasons, there is no need to exclude
rhododendron from feedstock accepted on to UK PAS 100 accredited
composting sites. The risk to livestock from grayanotoxin poisoning through
grazing grassland treated with PAS 100 green waste composts is likely to
be negligible.
Sumber:
http://www.jgpress.com/compostscience/archives/_free/002342.html….. Diunduh
22/4/2012
Predicting Nitrogen and Carbon Mineralization of Composted Manure and
Sewage Sludge in Soil
Compost Science & Utilization, (2011), Vol. 19, No. 1, 33-43
R.S. Antil, A. Bar-Tal , P. Fine and A. Hadas
The capability of organic wastes to
release available N in soil varies
largely, depending on their source and
form of production, or rather on their
composition and biodegradability.
Our purpose was to predict
mineralization rates of different
materials using their analyses
joined with a simulation model, and
to evaluate the influence of soil
type and application rate of the
organic materials on N and C
transformations in soil. Four
organic materials, sewage sludge
(SS), sewage sludge compost
(SSC), cattle manure compost
(CMC), hen and cattle manure
compost (HCMC), were applied to
two soils at rates of 2 and/or 4%.
The soils were incubated
aerobically for 168 days at 30oC,
during which CO2 evolution rates
and mineral-N concentrations were
measured periodically.
Hot water extractable C and N of all organic amendments correlated well with short term
C and N mineralization, except HCMC that immobilized N although its soluble N content
was large. NCSOIL, a computer model that simulates C and N cycling in soil with
organic amendments, predicted well C and N mineralization of SS, SSC and CMC when
considered as three-pool materials that decomposed at specific rates of 0.4, 0.024 and
10-4 d-1, using hot water soluble C and N as the labile pool. N immobilization by HCMC
could be simulated only if the distribution of N between the labile and resistant pools
was derived by optimization of NCSOIL, while hot water soluble C was labile.
Laboratory methods to determine an intermediate pool or components that contribute to
immobilization are required for improving the predictions of C and N mineralization from
organic amendments.
Sumber:
http://www.jgpress.com/compostscience/archives/_free/002344.html….. Diunduh
22/4/2012
Oxygen and Carbon Dioxide Distribution And Movement in Passively Aerated
Compost Piles
Compost Science & Utilization, (2011), Vol. 19, No. 1, 25-32
Tjalfe G. Poulsen
Distributions of O2 and CO2
concentrations across a cross
section of a full-scale passively
aerated, mechanically turned,
compost pile were measured as a
function of time over an 11 day
long period covering two pile
turnings.
The compost pile had a triangular
cross section, was 1.8 m high, 4.4
m wide, 80 m long and consisted of
sewage sludge, yard/park waste
and screening residue from
previously composted materials.
The measurements were
conducted in one cross section of
the pile. The O2 and CO2
concentration measurements were
used in combination with earlier
published measurements of air
permeability and air pressure
inside the compost pile to calculate
O2 and CO2 fluxes across the pile
surface as functions of time and
location as well as estimation of
total specific oxygen consumption
rates in the compost.
Distributions of O2 and CO2 concentrations inside the pile were relatively constant with
time and exhibited high O2 concentrations near the surface and high CO2
concentrations near the center of the pile.
Maximum O2 fluxes into the compost occurred along the lower edges of the pile and
equalled up to 15 kg/m-2 h-1 while maximum CO2 fluxes occurred at the center top of
the pile and equalled up to 700 g m-2 h-1.
Average daily CO2 emissions from the compost were up to 3.4 kg m3 d-1 while the
corresponding O2 flux into the compost pile was up to 53 kg m3 d-1. Average O2
consumption was 1.4 kg m-3 d-1 while average CO2 production was 1.5 kg m-3 d-1 at
the measurement location over the 11 day experimental period.
Sumber:
http://www.jgpress.com/compostscience/archives/_free/002345.html….. Diunduh
22/4/2012
Do Compost and Vermicompost Improve Macronutrient Retention and Plant
Growth in Degraded Tropical Soils?
Compost Science & Utilization, (2011), Vol. 19, No. 1, 15-24
EP. Jouquet , E. Bloquel , T. Thu Doan, M. Ricoy , D. Orange , C. Rumpel and T.
Tran Duc
Soil degradation and water pollution
are widespread land degradation
problems in Southeast Asia. Policy
makers are currently faced with the
challenge of designing and
implementing strategies to maintain soil
fertility and avoid off-site effects.
The aim of this study was to determine
the effect of organic substrate
amendments on soil properties, nutrient
leaching and the growth of Ipomea
aquatica in an acidic degraded soil from
northern Vietnam. Plants were grown in
an Acrisol in buckets under natural
weather conditions for two months. The
same amount of nutrients was applied
either in a purely synthetic form (mineral
fertilizers) or as two alternative organic
substrates (three month old compost or
vermicompost from buffalo dung) plus
additional amounts of synthetic mineral
nutrients to ensure the same quantity of
NPK. The influence of these respective
substrates on the soil’s physical and
chemical properties as well as plant
growth was examined. Both compost and
vermicompost led to an improvement in
soil properties with an increase in the pH,
soil organic matter and nutrient content,
compared to soil fertilized with synthetic
mineral products.
The highest plant productivity was obtained with vermicompost and synthetic fertilizers,
with no significant difference between these two treatments. Chemical fertilization,
however, is the least effective practice based on the amount of nutrients leached from
the soil (about 38% of N and 22% of K, compared to less than 10 and 5% of N and K
with organic amendments).
P leaching was not influenced by the fertilizer treatments. In conclusion, vermicompost
does appear to be a relevant alternative to chemical fertilizers because it leads to similar
enhancements in plant growth, at the same time as increasing soil quality and
decreasing nutrient leaching.
Sumber:
http://www.jgpress.com/compostscience/archives/_free/002346.html….. Diunduh
22/4/2012
Maturity Tests for Composts — Verification of a Test Scheme for Assessing
Maturity
Compost Science & Utilization, (2010), Vol. 18, No. 3, 174-183
M. Itävaara , M. Vikman , Maunuksela Liisa and A. Vuorinen
Increased recycling of organic wastes has raised
concern about the quality of compost end
products. In addition to the limit values for heavy
metals and impurities including weeds and
pathogens, the quality criteria for compost
products should also include criteria for maturity.
There is a tremendous number of maturity
assays, developed earlier by several authors,
and recommended to be used to evaluate
maturity of composts.
Because no such single test
alone reliably demonstrates the
complex properties occurring
during maturization of compost,
we developed a fast and easyto-use two-phase test scheme
for the assessment of maturity.
In the first phase the
degradation phase e.g. stability
of compost samples is
evaluated by using a carbon
dioxide evolution test and/or
determination of the NO3N/NH4-N ratio by simple test
strips. In the second phase, the
toxicity of the compost is
evaluated by a plant growth
test, germination tests and/or
the Flash bioluminescence test.
Eleven plants composting sewage sludge, source-separated biowaste, manure or a
combination of these raw materials were sampled after 1-3 weeks of composting and
when the compost was considered “ready for use”. Chemical and physical analyses were
considered useful as additional information when evaluating maturity especially when the
results were not conclusively clear. This fast and easy-to-use test scheme was designed
especially for the composting plant operators and official laboratories responsible for
evaluating compost quality.
Sumber:
http://www.jgpress.com/compostscience/archives/_free/002149.html ….. Diunduh
22/4/2012
The Role of Aeration Intensity, Temperature Regimes And Composting Mixture
on Gaseous Emission During Composting
Compost Science & Utilization, (2010), Vol. 18, No. 3, 194-200
Jan Habart , Pavel Tlustos, Ales Hanc, Pavel Svehla, Jaroslav Vána, Petr Tluka and
Frantisek Jelínek
The aim of the work was to
compare production of N2O
during composting with
different temperature regimes,
different aeration intensity and
different input mixture.
Two different mixtures of organic
material with three levels of
aeration underwent the composting
process in two temperature
regimes. Mixture A contained
woodchips, separated pig slurry,
fresh grass and tree leaves.
Mixture B contained woodchips,
tree leaves, grass and urea to
optimize C:N ratio. This experiment
was carried out in specially
designed 70 liter fermentors.
Oxygen and nitrous oxide were
monitored in the exhaust air as well
as pH, NO3- and NH4+ and
temperature of solid material.
The mixture with urea additive showed high N2O production when kept
under low temperature; when the same mixture was kept in higher
temperature, production of N2O was 3 fold lower. However, the mixture
without urea addition kept in high temperature shows almost no N2O
production. Production of N2O was highest when nitrates concentration
increased. Production of N2O is perhaps a by-product of nitrification, but
also other pathways may contribute.
Sumber:
http://www.jgpress.com/compostscience/archives/_free/002147.html….. Diunduh
22/4/2012
Composting Wet Olive Husks with a Starter Based on Oil-Depleted Husks
Enhances Compost Humification
Compost Science & Utilization, (2011), Vol. 19, No. 3, 182-188
M.C. Echeverria, R. Cardelli, S. Bedini, M. Agnolucci, C. Cristani, A. Saviozzi and M.
Nuti
Wet olive husks represent an
environmental problem in
Mediterranean areas but also a
potential resource as recyclable
organic matter.
In the present work, we
describe the composting of
wet olive husks, using
mechanically turned piles
without forced ventilation,
carried out to study the
effects of partially
composted oil-depleted
husks as a starter for wet
husks degradation.
At the beginning of the composting process, protease and dehydrogenase
activity, along with the microbial respiration, were higher in the piles with
the starter, demonstrating a higher microbial activity in comparison with the
piles without the starter.
At the end of the process, the compost with the starter showed a deeper
humification and a lower content of total organic carbon with respect to the
compost without the starter, indicating a higher level of biodegradation and
organic matter evolution.
The main outcome of this research includes the possibility to: (a) detoxify
and de-odorize a bad-smelling waste into an hygienically safe product; (b)
produce a green, mature, humified compost useful to restore soil fertility
and texture in intensive and organic agriculture.
Sumber:
http://www.jgpress.com/compostscience/archives/_free/002489.html….. Diunduh
22/4/2012
Amelioration of Composting Process by Fertilizers
Compost Science & Utilization, (2004), Vol. 12, No. 1, 80-85
Wan Rasidah Kadir , Rozita Ahmad , Hoi Why Kong and Ognian Stoyanov Kostov
Six different composts, four of
them produced from oil palm
residues and two commercial
composts, were studied for their
stability and quality.
The composts were
analyzed for their total
C, total N, C/N ratio,
mineral N, nitrogen
mineralization index,
CO2 production,
biomass C, specific
respiration rate,
germination rate, pH
values and plant growth
index.
Composts of oil palm (Elaeis guineesis) trunk and oil palm empty fruit bunch treated
with N and P showed good stability and higher quality as compared to other composts.
Their C/N ratios were the lowest (14-18) but their pH values were comparatively low
(4.6-6.4). They had a good amount of total N (0.95-1.84%) with higher nitrate than
ammonium nitrogen. The specific respiration rates were very low (0.25-0.63) which is
an indication that these two composts are stable. Plant growth test supported
conclusions based on the microbiological tests. Their properties were considered as
suitable for planting media application. Compost quality can be further improved by
adding bunch ash, which has high values of pH and is also a by-product from the oil
palm industry.
The applied nitrogen mineralization index could not be used with all kinds of composts
as stability index. Both of the commercial composts showed high C/N ratios (34-68)
and very low values of total and mineral nitrogen compared to oil palm residues
composts. They were considered having low nutritional value and not recommended
for planting media application.
Sumber:
http://www.jgpress.com/compostscience/archives/_free/000863.html….. Diunduh
22/4/2012
EFFECT OF MOLASSES ON REGROWTH OF E. COLI O157:H7 AND
SALMONELLA IN COMPOST TEAS
Compost Science & Utilization, (2004), Vol. 12, No. 1, 93-96
Brion Duffy , Chester Sarreal , Subbarao Ravva and Larry Stanker
Compost water extracts (compost
teas) are gaining popularity among
organic growers, largely because of
their disease suppressive activity
when applied to foliage or soil.
Production methods often
include addition of
supplemental constituents,
particularly molasses, to
stimulate plant-beneficial
microbial populations. We
have found that molasses
amendments also favor
regrowth of human
pathogenic bacteria, raising
public health concerns about
potential contamination of
treated crops, particularly
produce intended for fresh
consumption.
Using disease outbreak strains marked with green fluorescent protein
(GFP) and spontaneous antibiotic-resistance, we found that regrowth of
Salmonella enterica serovar Thompson and Escherichia coli O157:H7 was
positively correlated with molasses concentration.
For Salmonella, regrowth was also dependent on the type of starter
compost material used. Salmonella populations increased from 1 at time 0
to over 1000 CFU ml-1 in dairy manure compost tea with 1% molasses,
and from 1 at time 0 to over 350,000 CFU ml-1 in chicken manure compost
tea by 72 h.
E. coli populations increased from 1 at time 0 to approximately 1000 CFU
ml-1 in both types of tea by 72 h. Pathogen regrowth did not occur when
molasses was eliminated or kept to 0.2 %.
Sumber:
http://www.jgpress.com/compostscience/archives/_free/000865.html ….. Diunduh
22/4/2012
Organic Matter and Nitrogen Conservation in Manure Compost for Organic
Agriculture
Compost Science & Utilization, (2004), Vol. 12, No. 1, 6-10
Michael Raviv, Shlomit Medina, Arkady Krasnovsky and Hammam Ziadna
Compost is a main source of
organic matter (OM) and of
nitrogen for organic farming in
arid and semiarid regions.
An effort has been made to
reduce nitrogen loss during
composting of separated cow
manure (SCM) using high
C/N additives - wheat straw,
(WS), grape marc (GM) and
slightly acidic additive such
as orange peels (OP).
The resulting composts contained 2.63%, 2.84% and 2.39% N for the
GM-SCM, OP-SCM and WS-SCM, respectively. Values of N loss from the
raw mixtures were 18%, 5% and 2% for the three compost types,
respectively. OM values were 70%, 57% and 53% for the three compost
types, respectively.
Nutritional contribution of the composts was assessed using cherry
tomato as a test plant, growing in the composts as growing media. Peat
moss served as a control medium. The media were either unfertilized or
fertilized with guano.
Plant responses suggest that growth is mainly affected by nitrogen
availability while flower production and fruit set is also affected by
potassium availability. It was found that fertilization was not necessary for
at least 2 months after planting for OP-SCM and WS-SCM.
Sumber:
http://www.jgpress.com/compostscience/archives/_free/000853.html….. Diunduh
22/4/2012
Chemosphere. 2008 Jun;72(4):551-7. Epub 2008 May 7.
Co-composting of distillery wastes with animal manures: carbon and nitrogen
transformations in the evaluation of compost stability.
Bustamante MA, Paredes C, Marhuenda-Egea FC, Pérez-Espinosa A, Bernal MP,
Moral R.
The aim of this work was to study the
viability of recycling the solid wastes
generated by the winery and distillery
industry by means of co-composting
with animal manures, as well as to
evaluate the quality of the composts
obtained.
Two piles, using exhausted grape
marc and cattle manure or poultry
manure, respectively (at ratios, on
a fresh weight basis, of 70:30),
were composted by the Rutgers
static pile composting system.
Throughout the composting
process, a number of parameters
were monitored, such as pH,
electrical conductivity, organic
matter, water-soluble carbon,
water-soluble polyphenols, different
forms of nitrogen (organic nitrogen,
ammonium and nitrate) and
humification indices (humification
ratio, humification index,
percentage of humic acid-like C,
polymerisation ratio and cation
exchange capacity), as well as the
germination index.
Organic matter losses followed first-order kinetics equation in both piles, the highest
organic matter mineralisation rate being observed with exhausted grape marc and cow
manure. On the other hand, the mixture with the lowest C/N ratio, using exhausted
grape marc and poultry manure, showed the highest initial ammonium contents,
probably due to the higher and more labile N content of poultry manure. The increase
in the cation exchange capacity revealed the organic matter humification during
composting. In contrast, other humification parameters, such as the humification ratio
and the humification index, did not show the expected evolution and, thus, could not be
used to assess compost maturity.
Composting produced a degradation of the phytotoxic compounds, such as
polyphenols, to give composts without a phytotoxic character. Therefore, composting
can be considered as an efficient treatment to recycle this type of wastes, due to
composts presented a stable and humified organic matter and without phytotoxic
effects, which makes them suitable for their agronomic use.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/18466954 ….. Diunduh 28/4/2012
Chemosphere. 2008 Oct;73(5):670-7. Epub 2008 Aug 19.
Evaluation of carbon degradation during co-composting of exhausted grape
marc with different biowastes.
Fernández FJ, Sánchez-Arias V, Villaseñor J, Rodríguez L.
In this work the carbon
biodegradation of exhausted grape
marc (EGM) combined with other
organic wastes using the turned
pile composting system was
studied.
Four different piles were made of
EGM in Pile 1, EGM mixed with
cow manure and straw (CMS) in
Pile 2, EGM mixed with municipal
solid waste (MSW) in Pile 3 and
EGM mixed with grape stalks (GS)
in Pile 4.
The results obtained were
modelled to determine the main
kinetic and stoichiometric
parameters.
Regarding to the rate constants of the composting processes they were increased
from 0.033d(-1), the value obtained when EGM was composted alone, to 0.040 and
0.044d(-1) when MSW and GS were added, respectively as co-substrates. However,
the addition of CMS reduced the rate constant.
About the biodegradable carbon fractions, it was observed that the co-composting
reduced significantly the remanent carbon concentration after composting in all the
piles whilst increased the readily biodegradable carbon fractions from 35, the value
obtained when EGM was composted alone, to 50 and 60%, respectively when MSW
or GS were added.
As regards the temperature profiles, only Piles 1 and 4 achieved thermal hygienization
values and about the nitrogen losses, the lowest percentage of nitrogen loss took
place when GS were added, because of its optimum pH and C/N initial ratio. Thus,
though any of these wastes could be used for co-composting with EGM, the use of GS
as co-substrate and bulking agent for the co-composting process of EGM was
recommended.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/18715609 ….. Diunduh 28/4/2012
Waste Manag Res. 2009 Mar;27(2):119-28.
Co-composting of poultry manure with low quantities of carbon-rich materials.
Silva ME, Lemos LT, Cunha-Queda AC, Nunes OC.
To study the feasibility of cocomposting poultry manure with
low quantities of high-value,
carbon-rich materials experiments
to characterize three pilot-scale
piles were carried out.
The piles comprised poultry
manure (pile 1), poultry
manure and straw (pile 2)
and poultry manure and
sawdust (pile 3), using wood
chips as bulking agent.
Pile 1 presented the highest losses of organic matter and nitrogen
contents (> or = 92.9% and 92.0%, respectively). Although a thermophilic
phase (temperature > 40 degrees C) was not verified for this pile, the
final compost was stable (class IV) and free of pathogen indicator microorganisms but it was the most phytotoxic, and presented a humic and
fulvic acids ratio (HA/FA) that was less than 1. In contrast, piles 2 and 3
sustained thermophilic phases and produced stable (class V) and mature
(HA/FA > 1) composts.
Pile 2 showed the lowest loss in nitrogen content (88.9%) and produced
the final compost with the highest C/N ratio (14.7) and the lowest value
of electrical conductivity (3.9 mS cm(-1)).
This study showed that it is possible to reduce the costs of poultry
manure composting, namely the costs associated with the use of carbonrich materials, given that the final co-composts presented parameters
within the range of those recommended by the Second Draft Proposal
for compost quality.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/19244411 ….. Diunduh 28/4/2012
Waste Manag. 2009 Sep;29(9):2446-53. Epub 2009 May 17.
Co-composting rice hulls and/or sawdust with poultry manure in NE Argentina.
Leconte MC, Mazzarino MJ, Satti P, Iglesias MC, Laos F.
Rice hulls and sawdust are two common Crich wastes derived from rice and timber
agro-industries in subtropical NE Argentina.
An alternative to the current management of
these wastes (from bedding to uncontrolled
burning) is composting. However, given their
C-rich nature and high C/N ratio, adequate
composting requires mixing with a N-rich
waste, such as poultry manure.
The effect of different
proportions of poultry
manure, rice hulls and/or
sawdust on composting
efficiency and final compost
quality was studied.
Five piles were prepared
with a 2:1 and 1:1 ratio of
sawdust or rice hulls to
poultry manure, and 1:1:1
of all three materials (V/V).
Different indicators of compost stability and quality were measured.
Thermophilic phase was shorter for piles with rice hulls than for piles with
sawdust (60 days vs. 105 days).
Time required for stability was similar for both C-rich wastes (about 180
days).
Characteristics of final composts were: pH 5.8-7.2, electrical conductivity
2.5-3.3 mS/cm, organic C 20-26%, total N 2.2-2.9%, lignin 19-22%, total
Ca 18-24 g/kg, and extractable P 6-8 g/kg, the latter representing 60% of
total P.
Nitrogen conservation was high in all piles, especially in the one
containing both C-rich wastes.
Piles with sawdust were characterized by high total and available N, while
piles with only rice hulls had higher Si, K and pH. Extractable P was
higher in 1:1 piles, and organic C in 2:1 piles
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/19450961 ….. Diunduh 28/4/2012
Waste Manag Res. 2009 Mar;27(2):119-28.
Co-composting of poultry manure with low quantities of carbon-rich materials.
Silva ME, Lemos LT, Cunha-Queda AC, Nunes OC.
To study the feasibility of cocomposting poultry manure with low
quantities of high-value, carbon-rich
materials experiments to
characterize three pilot-scale piles
were carried out.
The piles comprised poultry
manure (pile 1), poultry
manure and straw (pile 2)
and poultry manure and
sawdust (pile 3), using wood
chips as bulking agent.
Pile 1 presented the highest losses of organic matter and nitrogen
contents (> or = 92.9% and 92.0%, respectively). Although a thermophilic
phase (temperature > 40 degrees C) was not verified for this pile, the
final compost was stable (class IV) and free of pathogen indicator microorganisms but it was the most phytotoxic, and presented a humic and
fulvic acids ratio (HA/FA) that was less than 1. In contrast, piles 2 and 3
sustained thermophilic phases and produced stable (class V) and mature
(HA/FA > 1) composts.
Pile 2 showed the lowest loss in nitrogen content (88.9%) and produced
the final compost with the highest C/N ratio (14.7) and the lowest value
of electrical conductivity (3.9 mS cm(-1)).
This study showed that it is possible to reduce the costs of poultry
manure composting, namely the costs associated with the use of carbonrich materials, given that the final co-composts presented parameters
within the range of those recommended by the Second Draft Proposal
for compost quality.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/19244411 ….. Diunduh 28/4/2012
Bioresour Technol. 2010 Feb;101(4):1239-46. Epub 2009 Sep 30.
Use of biochar as bulking agent for the composting of poultry
manure: effect on organic matter degradation and humification.
Dias BO, Silva CA, Higashikawa FS, Roig A, Sánchez-Monedero MA.
The aim of this study was to
evaluate the use of biochar
(produced by slow pyrolysis of
Eucalyptus grandis biomass) as
bulking agent for the composting of
poultry manure.
Three composting mixtures
were prepared by the turnedpile system by mixing poultry
manure with different organic
wastes used as bulking agent
(biochar, coffee husk and
sawdust) in a proportion of 1:1
(fresh weight).
Despite the inert nature of
biochar, the composting
mixture prepared with biochar
underwent an organic matter
degradation of 70% of the initial
content.
The organic matter of the poultry manure-biochar mixture was
characterised by a high polymerisation degree of the humic-like
substances, with a relative high proportion of humic acids in relation to
fulvic acids.
At the end of the composting process, the humic acid fraction represented
more than 90% of the alkali extractable fraction, reflecting the intense
humification of this material.
Enrichment of poultry manure with biochar reduced the losses of nitrogen
in the mature composts, although the use of sawdust would be more
efficient in preserving the organic matter and nitrogen in the mature
compost.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/19796932 ….. Diunduh 28/4/2012
Bioresour Technol. 2009 Jan;100(2):521-6. Epub 2008 Aug 8.
Strategies to reduce short-chain organic acids and synchronously
establish high-rate composting in acidic household waste.
Bergersen O, Bøen AS, Sørheim R.
The aim of this study was to
document whether addition of lime
or increased amount of bulking
agent would ensure, efficiently, a
predictable composting process in
acidic SSOW applicable in full scale
plants.
The results show that both
lime addition and
increasing the amount of
bulking agent relative to
waste support the
development of high-rate
respiration in composting.
Both strategies are considered efficient in establishing desired
microbial composting processes of acid household waste.
Reduction in the content of different organic acids and loss on
ignition were higher when more bulking agent was used
compared with adding 5% lime to the acidic SSOW.
Respiration was completely repressed in samples with 10% lime,
where pH remained high. In addition fat and protein seem to
degrade faster with increasing amount of bulking agent.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/18692391 ….. Diunduh 28/4/2012