Effluent
Characteristics and
Analysis Method
CDB 4223Z
Industrial Effluents & Waste residue
January 2019
POLLUTANTS/ CONTAMINANTS
L2-1
What’s in Wastewater? Contaminants
What is “Contaminant”?
1. Anything discharged?
2. Something which causes change – colour, turbidity?
3. Something which smells?
4. Something which makes us sick?
5. Something which kills fish and other aquatic species?
6. Something which causes damage?
7. Something which has a measurable impact?
8. Something which has a long term impact on human life and activity?
9. Something which gives the DOE an excuse to impose penalty?
L2-2
Principal contaminants of concern
Contaminants
Impact
Suspended solids
Can lead to the development of sludge deposits, anaerobic
conditions and smell.
Biodegradable organics
If discharged to the environment, their biological stabilisation can
lead to the depletion of natural oxygen resources and development
of septic conditions.
Pathogens
Communicable diseases can be transmitted.
Nutrients
Discharged in large amount can lead the growth of undesirable
aquatic life and pollution of groundwater.
Priority pollutants
Organic & inorganic compounds selected on the basis of their
known or suspected carcinogenicity, mutagenicity, teratogenicity or
high acute toxicity.
Refractory organics
Organics that resist conventional methods of wastewater
treatment. E.g. surfactants, phenols & agriculture pesticides
Heavy metals
Toxic to human organs, some can cause cancer, metabolism
failure, neurological problems.
Dissolved inorganics
Calcium, sodium & sulfate must be removed if the water is to be
reused.
L2-3
Pollutant category
• Physical
• Chemical
 Temperature
 Inorganic
 Solid
 Organic
 Turbidity
• Biological
 Colour
 Odour & taste
 Conductivity
L2-4
Physical characteristics
 Temperature
 Solid
 Turbidity
 Colour
 Odour & taste
 Conductivity
L2-5
Temperature
•
oxygen is less soluble at high
temperature
DO (mg/L)
Temperature
Oxygen
demand
•
Temperature (C)
increase in biochemical reactions rate
at high temperature
Oxygen
replenishment
Dissolved
oxygen
KT/K20
Temperature (C)
L2-6
Temperature
•
Other effects
• change in fish species
• mortality of fishes (thermal shock)
• increase growth of water plants and wastewater fungus.
L2-7
Solids
•
Solids is one of the most common assessments of water quality.
•
Solids – 3 categories
• Dissolved
• Truly in solution and pass through a filter.
• Homogenous and of a single phase
• Colloidal
• Uniformly dispersed in solution
• But form a solid phase that is distinct from the water phase.
• Suspended
• Separate from the solution.
• Some are settleable.
•
Method of analysis is given in APHA Method 2540.
L2-8
Solids
•
Three types of solids measured:
• Suspended solids
• Dissolved solids
• Volatiles suspended solids
•
Filtration is used to separate suspended
and dissolved solids.
• Commonly used filter paper is
Whatman glass fiber filter (1.58 m,
47 mm).
L2-9
Settable solids
•
Suspended solids that settle out of suspension within a specified
period of time (1 hour).
•
Standard test is by using Imhoff cone.
•
The solids that accumulate in the bottom of the cone is after 60 min.
is reported as mL/L.
L2-10
Total solids (TS)
•
It is the residue after a wastewater sample has been evaporated and
dried at 103 - 105°C.
•
Can be divided into 2
• total volatile solids (TVS) (volatilised & burned off when TS are
ignited at 500 ± 5°C)
• total fixed solids (TFS) (the remains after TS are ignited at 500 ±
5°C)
L2-11
Total suspended solids (TSS)
• Wastewater is firstly filtered and the filter paper is
weighed after being dried at 105°C.
• The remaining weight on the dried filter paper is TSS.
• Commonly used filter paper is Whatman glass fiber filter,
of 1.58 m.
• Can further divided into 2:
• volatile suspended solids (VSS) (volatilised & burned
off when TSS are ignited at 500 ± 5°C)
• fixed suspended solids (FSS) (the remains after TSS
are ignited at 500 ± 5°C)
L2-12
Total dissolved solids (TDS)
•
The solids that passed through the filter, and are then evaporated
and dried at 105°C.
(TS - TSS)
•
TDS is comprised of colloidal and dissolved solids.
•
Can be further divided into 2:
• total volatile dissolved solids (VDS) (volatilised & burned off
when TDS are ignited at 500 ± 5°C)
• fixed dissolved solids (FDS) (the remains after TDS are ignited
at 500 ± 5°C)
L2-13
Solids
•
Volatile solid
(VS) is
assumed to be
organic.
•
Fixed solid (FS)
is assumed to
be inorganic.
•
Ratio of VS to
FS gives an
approximate
amount of
organic matter
present in
wastewater.
L2-14
Exercise
•
The following test result were obtained for a wastewater sample
taken at an industrial facility. The tests were performed using a
sample size of 100 ml. Determine the concentration of total solids
(TS), total volatile solids (TVS), total suspended solids (TSS) and
dissolved solids (TDS) in mg/l.
Item
Weight
Tare mass of evaporating dish
54.6422
Mass of evaporating dish plus residue after evaporation at
105C
54.7022
Mass of evaporating dish plus residue after ignition at 550C
54.6722
Tare mass of filter paper
1.5348
Mass of filter paper plus residue after drying at 105C
1.5553
Mass of filter paper plus residue after ignition at 550C
1.5453
L2-15
Turbidity
•
It is a measurement of the clarity of water.
•
Turbidity is an indirect measurement of the amount of suspended
matter in water.
•
It is a test used to indicate the quality of water discharge and natural
waters with respect to colloidal and residual suspended matter.
•
It is an important measurement for drinking water because
microorganisms usually attach themselves to suspended particles.
•
Turbidity in natural waters reduces light transmittance and affects
the species that may live in the water.
•
The unit used is nephelometric turbidity units (NTU).
L2-16
•
Material that causes water to be turbid include:
• clay
• silt
• finely divided organic and inorganic matter
• soluble colored organic compounds
• plankton
• microscopic organisms
•
Removal – sedimentation, coagulation and flocculation.
L2-17
Schematic adapted from
"Turbidty: A Water Quality
Measure", Water Action
Volunteers, Monitoring
Factsheet Series,
UW-Extension,
Environmental Resources
Center. It is a generic, uncalibrated impact
assessment model based on
Newcombe, C. P., and J. O.
T. Jensen. 1996. Channel
suspended sediment and
fisheries: a synthesis for
quantitative assessment of
risk and impact. North
American Journal of
Fisheries Management. 16:
693-727.
L2-18
Colour
•
The age of wastewater is usually determined qualitatively by its
colour.
•
Fresh wastewater are usually light brownish-gray.
•
As the water gets older and more anaerobic conditions develop, the
colour will change sequentially from gray to dark gray and ultimately
to black.
•
Black wastewater - septic.
•
Dark colour wastewater is due to formation of metallic sulfide, which
is formed under anaerobic conditions.
•
Removal - coagulation, oxidation and adsorption
L2-19
Odour & taste
• Odour is related to taste
• Associated with the presence of:
• decaying organic matter
• living algae
• iron, manganese & metallic product
• industrial waste
• chlorine
• Odour – aromatic, earthy, swampy, septic and chemical.
• Odour removal – aeration, oxidation and adsorption.
L2-20
Conductivity
•
Measuring electrical conductivity of a water gives a good idea of its
total ionic content.
•
Unit used is S/cm where 1S = 1-1
•
It is a simple and reliable method in determining the purity of water
used for boiler feed or pharmaceutical preparation.
•
It is an indication of the total dissolved solids (TDS) of water.
L2-21
• Typical conductivity levels are:
Sea water
Potable water
Distilled water
50,000 S/cm
1000 S/cm
50 S/cm
Deionised water
Ultrapure water
1 S/cm
0.06 S/cm
• Can also be used to check:
• salinity
• ionic strength
• Approximately 2S/cm = 1 ppm
L2-22
Chemical Constituents
Inorganic
pH
Nitrogen
Phosphorus
Trace metals
Gases
Organic
Oxygen demand
parameter
Oil and grease
Total organic carbon
(TOC)
Single organic
constituent
Alkalinity
Hardness
Aggregate organic
constituents
L2-23
pH
•
Toxicity of many compounds is affected by pH.
• H2S ~ toxicity to fish increases as pH is lowered.
•
Solubility of heavy metals
• Lower pH increases solubility of metals such as aluminium
• Metals leaches from soil and sediment into surface water
• Accumulate to fish gills or cause deformity ~ death
•
The pH of water determines the solubility (amount that can be
dissolved in the water) and biological availability (amount that can
be utilized by aquatic life) of chemical constituents such as nutrients
(phoshorus, nitrogen, and carbon) and heavy metals (lead, copper,
cadmium, etc.).
L2-24
pH
L2-25
Nitrogen and Phosphorus
•
From fertilizer, laundry detergent etc.
•
Excess nitrate in drinking water can
cause BLUE BABY SYNDROME.
•
Excess nitrogen and phosphorus can
cause EUTROPHICATION or ALGAE
BLOOM.
Eutrophication is
apparent as
increased turbidity
in the northern part
of the Caspian Sea,
imaged from orbit.
L2-26
Eutrophication
Note the bright green colour caused
by algae stimulated by the
experimental addition of nutrient for
the 26th consecutive year. The lake
in the background is unfertilized.
Source : www.bbc.co.uk
L2-27
Nitrogen and Phosphorus
•
The specific nitrogen tests conducted depends on the objective of
the study.
 Drinking water – nitrate (NO3-)
 Polluted stream – ammonium nitrogen (NH3 & NH4+)
•
In aqueous solution the usual forms are orthophophate (H2PO4-,
HPO42, PO43), polyphosphate (Na3(PO3)6) and organic phosphate.
L2-28
Trace metals
•
Affect flora and fauna through bioaccumulation
•
Affect human organs
• Arsenic – mutagen and carcinogen
• Cadmium – carcinogen, accumulates in liver and kidney
• Chromium – carcinogen, corrosive and skin sensitizer
• Lead – brain and kidney damage
• Mercury – highly toxic, damage to nervous system
• Selenium – weakness, depression and red staining
• Silver – grey colouration of skin
•
But minute amount of heavy metal is essential for human health
L2-29
Gases
•
Gases found in untreated wastewater include:
• nitrogen
• oxygen
• carbon dioxide
• hydrogen sulphide
• ammonia
• Methane
• VOC
L2-30
Dissolved oxygen
Factors that effect DO levels
•
Temperature
•
Photosynthetic activity
•
Decomposition activity
•
Mixing and turbulence
•
Salinity
L2-31
Alkalinity
• It is the capacity to neutralise acids (buffer).
• Most alkalinity is caused by carbonates & bicarbonate.
• Others:
• Carbonate
• Hydroxide
• Phosphate
• Borate and other ions.
• Lime in water softening and coagulants for turbidity
removal react with alkalinity, thus to ensure optimum
dosages of treatment chemical, alkalinity is monitored.
L2-32
Measurement of alkalinity
• M Alkalinity (boiler water)
• Also known as total alkalinity
• Measures carbonate, bicarbonate and hydroxide
• Measurement using methyl orange indicator (end
point is about 4.4)
• Unit ppm CaCO3
• p Alkalinity
• Measures carbonate and hydroxide
• Measurement using phenolphtalein indicator (end
point is about 8.2)
• Unit ppm CaCO3
L2-33
Hardness
•
Caused by multivalent metallic cations – calcium and magnesium.
•
Ca2+ and Mg2+ in hard water caused precipitation of soap, reduction
in its cleaning power and cause scale in water distribution systems
and hot-water heaters.
•
Soft (<50 mg/l); Moderately hard (<150 mg/l); Very hard (>300 mg/l)
•
Testing method – EDTA titrimetric method with Eriochrome Black T
as indicator.
•
Hardness is expressed in terms of milligrams CaCO3 per liter.
L2-34
Oxygen Demand Parameter
TOD
Not oxidisable
Chemically oxidizable
COD
Not biologically
degradable
Hard BOD
TOD: Total Oxygen Demand
COD: Chemical Oxygen Demand
Biologically
degradable
BOD
• Large molecules
• May take days/
hours to degrade
Soft BOD
• Small molecules
• Taken up directly
BOD: Biological Oxygen Demand
L2-35
TOD
•
Estimation of TOD can be done and the value is known as
Theoretical Oxygen Demand (ThOD).
•
Corresponds to the stoichiometric amount of oxygen required to
oxidise completely a given compound.
•
It can also be used to calculate the amount of oxygen required to
oxidise the ammonia present in the water of wastewater, which is
known as Nitrogenous Oxygen Demand (NOD).
L2-36
Exercise
A chemical plant produces the amino acid glycine
(C2H5O2N). Wastewater from the facility contains
approximately 30 mg/L of this acid. Calculate both the
carbonaceous and nitrogenous ThOD for the wastewater.
Assume:
• In the first step, the organic carbon and nitrogen are
converted to carbon dioxide (CO2), ammonia (NH3)
and water. This is for carbonaceous ThOD.
• In the second and third steps, the ammonia is
oxidised sequentially to nitrite (HNO2) and water; and
nitrate (HNO3). This is for nitrogenous ThOD.
L2-37
Additional info.
•
Reactions
1st step reaction:
C2H5O2N + 3/2O2  2CO2 + NH3 + H2O
2nd step reaction:
NH3 + 3/2O2  HNO2 + H2O
3rd step reaction:
HNO2 + ½O2  HNO3
•
MW:
C = 12, H = 1, O = 16, N = 14
L2-38
Chemical Oxygen Demand (COD)
•
•
•
Useful indicator of water quality
Indicate amount of organics in wastewater
Measured by determining the mass of oxygen consumed per liter of
wastewater (in mg/L or parts per million, ppm)
Note: For illustration purpose, detail method will be based on standards
Add oxidising reagent
(dichromate in acid
solution) – to convert
organics
Organics consumes oxygen
in reagent (2 hours)
Determine how much
oxidizing reagent left
Wastewater Sample
Wastewater Sample
Wastewater Sample
Organics
Organics react
with O2 in reagent
No more organics
Some reagent left
COD = oxygen in consumed reagent = oxygen in initial reagent – oxygen in reagent left
Interference
• Oxidisable inorganic material such as Chloride may give wrong(higher) reading
• Need to eliminate chloride first with mercuric sulfate
L2-39
COD
•
Usually COD > BOD.
•
COD analysis is relatively fast compared with BOD analysis.
•
Therefore, wastewater personnel often use COD analysis to obtain
information quickly for plant operation.
L2-40
Biological Oxygen Demand (BOD)
•
•
•
•
Another useful indicator of water quality
Also indicate amount of organics but only those consumed by
micro-organisms – may also be known as biodegradable organics
Also measured by determining the mass of oxygen consumed per
litre of wastewater (mg/L or parts per million, ppm)
Test is under aerobic conditions at a standardised temperature and
time of incubation.
Note: For illustration purpose, detail method will be based on standards
Measure dissolved
oxygen in wastewater
Micro-organisms in
wastewater consumes
organics (5 days)
Measure how much
dissolved oxygen left
Wastewater Sample
Wastewater Sample
Wastewater Sample
Biodegradable
Organics + microbes
Microbes eat organics
and use oxygen
Microbes eat less
organics
BOD5 = DO comsumed = DO initial – DO after 5 days
L2-41
Basis of BOD test
energy
Oxidation
Bacteria &
COHNS
O2
Endogenous
respiration
energy
O2
Ingestion
Synthesis
End
products
New cell
tissues
C5H7NO2
Stable
organic end
products
O2
L2-42
Basis of BOD test
• The standard condition for BOD analysis are at 20°C, in
the dark and an excess of nutrients for the
microorganisms.
• Due to variability of the test, analyses are performed in
duplicate.
• BOD5 is for 5 days analysis.
• BODu is for ultimate test of 20 or 30 days of analysis.
• The analysis can be carried out with or without seed.
• Seed - it is the microorganism that is contained in the
effluent from primary sedimentation.
• Wastewater with low concentration of organism require
seeding.
L2-43
BOD test - Unseeded
L2-44
BOD test calculation - unseeded
•
To get the value of BOD, the difference of dissolved oxygen is
measured.
•
Unseeded dilution water:
BOD, mg/L 
•
D1 - D2
P
(1)
where D1 = dissolved oxygen of diluted sample immediately after preparation, mg/L
D2 = dissolved oxygen of diluted sample after 5-day incubation at 20°C, mg/L
P = fraction of wastewater sample volume to total combined volume: Vs/300ml
L2-45
BOD test - Seeded
L2-46
BOD test calculation - seeded
•
Seeded dilution water:

D1  D2   B1  B2  f
BOD, mg/L 
(2)
P
Where
B1 = dissolved oxygen of seed control before incubation, mg/L
B2 = dissolved oxygen of seed control after incubation, mg/L
f = fraction of seeded dilution water volume sample to volume of seeded dilution
water in seed control
L2-47
L2-48
Exercise
The following information is available for a seeded 5-day
BOD test conducted on a wastewater sample. 15 mL of the
waste sample was added directly into a 300-mL BOD
incubation bottle. The initial DO of the diluted sample was
8.8 mg/L and the final DO after 5 days was 1.9 mg/L. The
corresponding initial and final DO of the seeded dilution
water was 9.1 and 7.9 respectively. What is the 5-day BOD
(BOD5) of the wastewater sample?
L2-49
Modeling of BOD reaction
• The
rate of BOD oxidation is governed on the
assumption that the amount of organic material
remaining at any time t is a first-order function.
dBOD r
 k1BOD r
dt
• Integrating between the limits of UBOD and BODt and t =
0 and t = t yields
BOD r  UBODe k1t 
(3)
BODr = amount of remaining BOD at time t, mg/L
k1 = first-order reaction rate, 1/d
UBOD = total or ultimate carbonaceous BOD, mg/L
t = time, d
L2-50
•
BOD exerted up to time t is
BOD t  UBOD - BOD r
 UBOD - UBODe k1t 
 UBOD1  e k1t 
•
(4)
The rate constant k1 is usually given for temperature of 20C. It is
possible to know the value for different temperature by the van’t
Hoff-Arrhenius relationship.
k1T  k120 T 20
•  = 1.056 at temperature of 20 to 30C
(5)
•  = 1.135 at temperature of 4 to 20C
51
L2-51
Exercise
A typical wastewater has a BOD5 20°C of approximately 220 mg/L. If
the k1 for it is 0.23 day-1 (base e):
1. What is the ultimate BOD?
2. What is the 3-day BOD?
What would have been the 5-day BOD if the test is conducted at
25C?( = 1.056)
L2-52
Analysis of BOD data
•
In order to obtain the value for UBOD from the BOD5, the value of k
is required.
•
This can be done in through various methods:
• Thomas method
• Least squares method
• Moments method
• Daily-difference method
• Rapid-ratio method
• Fujimoto method
53
L2-53
Thomas method
dBOD r
 k1BOD r
dt
• BODr = L ;
dL
 k1 L
dt
(6)
• where:
• L = the concentration of organic matter expressed as O2
• k1 = rate constant
BOD t  UBOD - BOD r
 UBOD - UBODe k1t 
 UBOD1  e
 k1t

x  La - L
Assumed to be
a first-order
kinetics
mechanism
 
 L 1  e   L 1  10 
 La - La e  k1t
 k1t
a
 k1' t
a
L2-54
•
In finding k and La, from x-t data, difficulty arises because of the
exponential term.
•
Thomas recognised that the (1-10kt) term is similar to the function
 2.3 
2.3kt1 
kt 
6 

•
3
(7)
x can be approximated by
 2.3 
x  2.3La kt1 
kt 
6 

3
(8)
L2-55
• Rearranging (8) into a linear equation by solving t/x,
t
1  2.3 

kt 
1 
x 2.3La k 
6 
3
(9)
• Taking the cube root and rearranging,
 2.3k    1 
t

t  
  
13

 x
 6 La   2.3La k 
13
y
• Slope, m = S;
13
23
=
m
x+
 2.3k 2 3 
S
13

6
L


a
(10)
c
(11)
13
• Intercept, c = I;
 1 

I  
 2.3kLa 
(12)
L2-56
• Solving these two equations, the unknowns are found to
be:
k
6S
S
 2.61 (k in base 10) (13)
2.3I
I
1
La 
2.3kI 3
(14)
• The procedure for the Thomas method is to:
• Construct a table with columns for ti, xi, ti/xi and (ti/xi)1/3
• Plot (t/x)1/3 versus t and draw the best fitting curve.
• Obtain S and I from the curve and use (13) and (14) to
solve for k and La.
L2-57
Single Organics – Priority Pollutants
L2-58
www.epa.gov/NE/npdes/permits/generic/prioritypollutants.pdf
Single Organics
•
Priority pollutants - based on their known or suspected
carcinogenicity, mutagenicity, tetratogenicity or high acute toxicity.
•
Volatile organic carbons (VOC) - some are listed as priority
pollutants. In total they cause a great concern because:
• in vapour state, they are much more mobile and more likely to be
released to the environment
• the presence of some VOC may pose significant public health
risk
• they contribute to a general increase in reactive hydrocarbons in
the atmosphere, which lead to the formation of photochemical
oxidants.
L2-59
Single Organics
•
Disinfection byproducts - some are known or suspected potential
human carcinogens such as trihalomethanes (THMs), haloactic
acids (HAAs), trichlorophenol and aldehydes.
•
Pesticides and Agricultural Chemicals - most are toxic to many
organisms.
•
Emerging Organic Compounds - veterinary and human antibiotics,
industrial and household wastewater products, human prescription
and non-prescription drugs and sex and steroidal hormones.
L2-60
Biological characteristics
•
Important because some of the organisms can cause serious illness
whereas some are important in wastewater treatment.
•
Organisms found in surface water and wastewater include bacteria,
fungi, algae, protozoa, helminths, plants and animals.
•
Disease transmitted through water: typhoid, cholera, dysentery and
jaundice.
L2-61
Removal
•
Coliforms and enterococci: oxidation and high pH.
•
Salmonella, shigella and vibrio: waste stabilisation, chlorination and
oxidation ponds.
•
Removing the above depends on: pH, temperature, retention time
and composition of wastewater.
•
Parasites: trickling filters and activated sludge.
•
Virus: activated sludge, oxidation ponds, chemical coagulation,
chlorination and ozone.
L2-62
Typical Pollutants by Industry Sector
Refining
Water as % product
Hydrocarbons
Other pollutants
Desalter
5–6%
50 – 150 mg/l
NaCl, phenols, sulphides
Catalytic Crackers
6 – 10 %
100 – 150 mg/l
Sulphides, mercaptans,
NH4+, phenols
Condensates
2 – 2.5 %
50 mg/l
NH4+, phenols
Vac Condensates
1 – 1.5 %
150 mg/l
NH4+, phenols
Desulpurization
NaOH, phenols, sulphides
Steam Cracking
Ethylene, propylene,
butadiene
Hydrocarbons
Other pollutants
Phenols, organic acids, other
hydrocarbons
Sulphides
Source: Degremont Water Treatment Handbook
L2-63
Typical Pollutants by Industry Sector
Reforming
Methanol, Ammonia, Urea
Hydrocarbons
Other pollutants
Methanol, heavy alcohols
Ammonia, Urea
Hydrocarbons
Other pollutants
Derivatives
MTBE
Ethylene Oxide
Methanol, isobutene
Ethylene Glycol, CO2, acetaldehyde,
hydrocarbons
Acetic Acid
Formic acid, acetates, acetone
Acidic water, iodides,
rhodium
Vinyl Chloride
Dichloroethane, hydrocarbons
HCl, NaCl
Polyethylene
PVC
Oil, TSS, catalysts
Methanol, acetates
Source: Degremont Water Treatment Handbook
Acidic water, TSS
L2-64
SAMPLING AND CHARACTERIZATION
L2-65
Sampling and Analytical Procedure
Sampling:
1. Representative
2. Reproducible
3. Defensible
4. Useful
Sampling Protocol in Quality Assurance Plan:
1. Sampling plan
2. Sample types and sizes
3. Sample labeling and chain of custody
4. Sampling methods
5. Sampling storage and preservation
6. Sample constituents
7. Analytical methods
L2-66
Parameter Testing
Physical analysis
•
•
Commonly monitored at site
near the sampling point due to
its chemical properties
For example:
Chemical analysis
•
Analysis is done in the lab
•
Samples require preservation
if transportation period
exceeds 8 – 24 hours
• Dissolved oxygen
• pH
• Temperature
• Ammonia
• Turbidity
• Free chlorine
L2-67
Sample Preservation
L2-68
Testing Platform
•
Portable system – for in-situ analysis
• Example: pH meter, DO meter etc
•
Laboratory system – for laboratory analysis
• Apparatus depends on
• Chemical to be tested
• Detection limit
• Cost
• Example: Spectrophotometer, UV-Vis, Atomic Absorption
Spectroscopy (AAS), Gas Chromatography, Liquid
Chromatography, ICP-MS etc
•
On-line system – for continuous monitoring
• COD, Ozone etc
L2-69
Testing Methodology
•
American Public Health Association (APHA) methodology ~
Standard Methods for Wastewater and Water Examination Book
•
USEPA
•
ISO Guide
L2-70
Characterization
•
Determine:
• flowrate
• contaminants
• concentration
• source of contaminants
•
Flowrate – use flow meter preferably closest to the source
•
Contaminants (parameters) – typical ones are temperature, pH,
suspended solids, COD, BOD and oil and grease, others such as
heavy metals, ammonia etc. depends on nature of plant
•
Concentration – must measure based on standards recognised by
DOE (APHA, ASTM)
CRITICAL to determine characteristics of wastewater to
• know what to treat
• know what to monitor
L2-71