CH. 13. Solid-Waste Management
13.1. Introduction
SOLID WASTE
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Definition
Categories
Examples
Municipal solid waste (MSW)
70 % of MSW (valuable material such as glass,
metal, and paper) could be recycled, however, only
one-third of it was recycled in 2010, the rest was
either incinerated or landfilled.
In 2010, Americans generated 250 million tons of
trash
Waste disposal increased
1,350-1,606 lb/person/year in 1980-2010
Amount of MSW generated by typical families (in one week) around the world
Japan, $317.25
Italy, $260.11
Chad, $1.23
Kuwait, $221.45
USA, $341.98
Mexico, $189.09
Ecuador, $31.55
USA, $159.18
If we are running out of space and contaminating our groundwater by burying our
trash, and contaminating the air by burning our waste, What can we do?
1) Recycle paper, glass, and metal (pizza boxes are not recyclable!)
2) Compost organic waste at home
3) Consume less, 30% of our waste is composed of packaging!
Compost
Solid waste management in Ukraine
A useful handbook for reducing solid waste.
http://www.epa.gov/epawaste/wycd/catbook/index.htm
The objective of an Integrated Solid Waste Management is to avoid the use of landfill
and incineration resources as much as possible as means of waste disposal. Thus, what it
proposes is to reduce the amount of trash we generate by consuming as less as possible
and reusing what we already own (or for instance visiting garage sales), and finding
alternative programs such as recycling and composting. The final desired resource would be
waste disposal such as incineration and landfill.
In the USA, the total amount of municipal solid waste generated increased from 88 million
of tons in 1960 (2.6 pounds/person/day) to 250 million of tons in 2010 (4.4
pounds/person/day), however you can observe in the chart above, that in 2005, the
generation of waste per capita, and thus the total amount of waste generated per year,
leveled off. This shows that we are doing well watching the amount of waste we generate,
but there still so much work to be done.
Inappropriate management of solid waste includes:
Solid waste disposed in rivers reaches the
ocean and finally concentrates along the
beaches in Mumbai, India.
Industrial waste (used engine oil) in a
ditch in Male’, Maldives contaminates the
groundwater.
Recycling
Increased
<10% in 1980
to 34% in 2010
Potential disease transmission in a local grocery
and meat market beside disposed waste in Haiti.
A bicycle that recycles metal!
http://www.fastcodesign.com/1671723
/a-safe-and-easy-way-to-mine-metalsfrom-e-waste
13.2.Solid waste characterization
Typical percentage that makes up municipal solid waste (MSW).
Source
Examples
Comments
Typical
percentage
of MSW
Residential
Detached homes, apartments
Food wastes, yard/garden wastes, paper, plastic,
glass, metal, household hazardous wastes
30-50%
Commercial
Stores, restaurants, office buildings, motels,
auto repair shops, small business
Same as above but more variable from source to
source. Small quantities of specific hazardous
wastes.
30-50%
Institutional
Schools, hospitals, prisons, military bases,
nursing homes
Same as above; variable composition between
sources.
2-5%
Construction/
demolition
Building construction or demolition sites, road
construction sites
Concrete, metal wood, asphalt, wallboard, and
dirt predominate. Some hazardous wastes
possible.
5-20%
Municipal
services
Cleaning of streets, parks, and beaches; water
and wastewater treatment grit and biosolids,
leaf collection, disposal of abandoned cars and
dead animals
Waste sources vary among municipalities.
1-10%
Industrial
Light and heavy manufacturing, large foodprocessing plants, power plants, chemical
plants
Can produce large quantities of relatively
homogeneous wastes. Can include ashes, sands,
paper mill sludge, fruit pits, tank sludge.
Not MSW
Agricultural
Cropping farms, dairies, feedlots, orchards
Spoiled food wastes, manures, unused plant
matter (e.g., straw), hazardous chemicals
Not MSW
Mining
Coal mining, uranium mining, metal mining,
oil/gas exploration
Can produce vast amounts of solid waste needing
specialized management
Not MSW
13.2.Solid waste characterization
Quantities of generated and recovered waste in 2010.
Material
Weight generated
(millions of tons)
Weight recovered
(millions of tons)
Recovery as percent of
generation (%)
Paper and paperboard
71.31
44.57
62.5
Glass
11.53
3.13
27.1
Steel
16.90
5.71
33.8
Aluminum
3.41
0.68
19.9
Other nonferrous metals
2.10
1.48
70.5
Total metals
22.41
7.87
35.1
Plastics
31.04
2.55
8.2
Rubber and leather
7.78
1.17
15.0
Textiles
13.12
1.97
15.0
Wood
18.88
2.30
14.5
Other materials
4.79
1.41
29.4
Total materials in products
177.86
64.97
36.5
Food, other
34.76
0.97
2.8
Yard trimmings
33.40
19.20
57.5
Miscellaneous inorganic wastes
3.84
negligible
negligible
Total other wastes
72.00
20.17
28.0
Total municipal solid waste
249.86
85.14
34.1
Metals
Other wastes
13.2.Solid waste characterization
Physico-chemical and biological characteristics.
• Density
• size distribution
• Moisture content
• Color,
• Odor,
• Shape,
• Optical properties
• Electric properties
• Magnetic properties
Waste type
Fungus
Protozoa
Bacteria
Insect
Rodent
Biomedical waste
X
X
X
X
X
Food waste
X
X
X
X
X
X
X
X
X
X
X
X
Hazardous waste
Municipal solid
waste
Radio active
waste
WEEE
13.2.Solid waste characterization
Physico-chemical and biological characteristics.
E. Coli contamination usually starts at
slaughterhouses.
Research conducted by Novotny et al. (2004)
shows species of bacteria present in fish that
are sources of human infections. These
organisms are generally found in fish
markets, floors, and fish boxes, specially
during the summer.
13.2.Solid waste characterization
13.2.Solid waste characterization
13.2.Solid waste characterization
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50% paints and paint products
20% used motor oil
20% solvents, pesticides and herbicides
10% batteries, unidentified materials and other miscellaneous items, such as
old chemistry sets, photographic materials, and fiberglass epoxy.
13.3.Components of the solid-waste system
Storage
Commercial
Residential
Construction
and
demolition
Institutional
Municipal
services
Collection
Transfer
station
Materials
recovery
facility
Incineration
Composting
Landfill
Compost
Recycled
materials
Compost
Storage
Storage is the immediate stage after generation, or before final disposal or
recycle/reuse. Storage duration depends on the collection process, which varies from
once to twice per week. There are many designs for storing waste. The table below
summarizes the most common containers for solid waste storage.
Different categories of storage containers:
Storage
Municipal solid waste storage containers
Rubbish skip is used
to transfer the waste
to special vehicles or
for door-to-door
collection.
Dumpsters are large
steel containers used
to transfer the waste
to large transportation
trucks.
Solid waste is stored
without safety
precautions in many
countries.
Storage
Storage of hazardous materials
There are various storage units such as containers, tanks, drip pads, waste piles, surface
impoundments, or containment buildings designed to house chemicals, flammables,
solvents, paint, explosives, and other hazardous materials. The storage of hazardous
materials need to comply the regulatory requirements specified by RCRA (Resource
Conservation and Recovery Act).
Storage of hazardous materials
in buildings.
Federal regulations allow small quantity hazardous
waste generators (100-1000kg) to store the waste
for up to 270 days without permit.
http://www.gpo.gov/fdsys/pkg/CFR-2012-title40-vol27/xml/CFR-2012-title40-vol27-part264.xml
Collection
Front-end loading vehicles are
commonly used for commercial
collection
Side- and rear-end loading
vehicles are commonly used
for residential collection
Collection
Collection of solid waste in developing countries is more inefficient. Most of the budget
is spent in collection and yet, they are not able to collect all the generated waste.
Collection varies from household level (called primary), where waste is collected from
individuals using bicycles, handcarts, private trucks, horses, etc. as medium of
transportation and then put into community collection containers. The secondary
collection system is then performed by the city council using small mechanical vehicles,
trucks, and tractors.
Solid waste management
in Africa.
Collection
Collection of solid waste in developing countries
Collection
Collection of solid waste in developing countries
http://www.swlf.ait.ac.th/Slide%20Show/Collection.pdf
Collection
Collection of solid waste in developing countries
Collection
Street sweeping in developing countries
Composting
Biodegradable plastic
containers are marketed as
compostable, but they don’t
completely degrade and may
in fact contaminate the
compost.
http://grist.org/food/is-your-cup-compostable-or-just-biodegrable-and-why-does-it-matter-again/
Composting
Composting
Composting systems perform best when the carbon-to-nitrogen ratio is in the range
of 20-40 (C:N 20:1 to 40:1), which means that carbon content is 20-40 times larger
than nitrogen. Table 13.11 in your textbook shows nutrient content of various
materials used in composting.
Material
Nitrogen (% dry mass)
C:N ratio (dry mass basis)
Potato tops
1.5
25
Wheat straw
0.3-0.5
130-150
Fresh leaves
0.5-1.0
41
Food wastes
3.2
16
Mixed paper
0.19
230
Yard wastes
2.0
23
Learn how to compost correctly:
http://greenliving.nationalgeographic.com/compost-correctly-2358.html
Recycling
Materials recovery facility.
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2.
3.
4.
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6.
7.
8.
9.
10.
11.
12.
13.
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21.
22.
Scale
Tipping floor
In-feed conveyor
Pre-sort
OCC screen
ONP screen
Glass breaker screen
Paper sorting
Commingle conveyor belt
Plastic sorting
Steel magnet
Optical sorter
Eddy current separator
Balers
Bale storage
Glass cleanup system
Glass bunker
Residue belt
Residue bunker
Outbound truck
Education center
Offices
http://www.recommunity.com/interactive-mrf/
Recycling
Recycling
Recycling
Recycling
Landfill
Landfill decomposition pathways:
1) Initial adjustment phase: Microorganisms adjust to the landfill conditions.
2) Transition phase: Transformation from aerobic to anaerobic environment.
3) Acid formation phase: Volatile organic acids are formed during biodegradation of
organic waste.
4) Fermentation phase: Generation of carbon dioxide, hydrogen sulfides, methane, and
ammonia due to microbial reactions of organic acids.
5) Maturation phase: Biodegradation stops or develops at lower rate. Leachate
production is lower as well.
Landfill
Typical anatomy of a landfill
Landfill
Landfill
Landfill
Incineration
Incineration, also called waste-to-energy, is one of the most widely used methods to
dispose combustible waste by using high temperatures (800-1050C) to convert
waste into flash, flue gas, and heat. The process can be optimized by using waste
with high energy content, low moisture, and low ash content.
Advantages:
Volume of waste is reduced (~80-85%) so landfills are avoided
Water content in waste can be used as steam to heat systems or generate electricity
Cost of transportation of municipal solid waste is reduced
Disadvantages:
High construction and operating costs.
Fly ash and generated particles need to be eliminated from the resultant emissions
before releasing to the air by air pollution control equipment
Toxins such as dioxins, furans, mercury, volatile metals, nitrous oxides are also
released during the combustion process and need to be eliminated before releasing
to the air.
Incineration
3. Steam formed
inside the incinerator
is recovered to fuel
turbines to produce
energy
2. Burning process.
Temperatures range
800-1050C. Initial
volume of the waste
is reduced 80-85%
1. Municipal solid
waste. Includes paper,
textiles, rubber,
leather, wood, etc.
6. Ashes are
recovered and
disposed in landfills
4. Toxic
compounds
and particles
are captured to
ensure good
quality of the
released air
5. The resultant gases
are clean and follow
federal air quality
regulations.
How many times can something be recycled?
http://earth911.com/news/2012/11/12/how-many-times-can-materials-berecycled/paper-bales-our-flickr/
How much energy does recycling save?
http://greenliving.nationalgeographic.com/much-energy-recycling-save-2363.html
Recycling facts
http://www.recyclingtown.com/
http://www.recycling-revolution.com/recycling-facts.html
How to identify hazardous waste
http://www.in.gov/idem/5043.htm#step3