CH. 13. Solid-Waste Management

13.1. Introduction

SOLID WASTE

• 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 home3) 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 landfilland 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 millionof 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.

Potential disease transmission in a local grocery and meat market beside disposed waste in Haiti.

RecyclingIncreased

<10% in 1980to 34% in 2010

A bicycle that recycles metal! http://www.fastcodesign.com/1671723/a-safe-and-easy-way-to-mine-metals-from-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 food-processing 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

Metals

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

Other wastes

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

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

Hazardous waste

Municipal solid waste

X X X X X

Radio active waste

WEEE X X

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

• 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 Collection Composting Landfill

Residential

Commercial

Construction and

demolition

Institutional

Municipal services

Transfer station

Materials recovery facility

Incineration

Recycled materials

Compost

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

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.

Municipal solid waste storage containers

Solid waste is stored without safety precautions in many countries.

Storage

Storage of hazardous materialsThere 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

Side- and rear-end loading vehicles are commonly used for residential collection

Front-end loading vehicles are commonly used for commercial 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

Street sweeping in developing countries

Collection

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.1. Scale2. Tipping floor3. In-feed conveyor4. Pre-sort5. OCC screen6. ONP screen7. Glass breaker screen8. Paper sorting9. Commingle conveyor belt10. Plastic sorting11. Steel magnet12. Optical sorter13. Eddy current separator14. Balers15. Bale storage16. Glass cleanup system17. Glass bunker18. Residue belt19. Residue bunker20. Outbound truck21. Education center22. 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 (800-1050C) 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 avoidedWater content in waste can be used as steam to heat systems or generate electricityCost 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 equipmentToxins 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

2. Burning process. Temperatures range 800-1050C. Initial

volume of the waste is reduced 80-85%

1. Municipal solid waste. Includes paper,

textiles, rubber, leather, wood, etc.

3. Steam formed inside the incinerator is recovered to fuel turbines to produce

energy

5. The resultant gases are clean and follow

federal air quality regulations.

4. Toxic compounds and particles

are captured to ensure good quality of the released air

6. Ashes are recovered and

disposed in landfills

How many times can something be recycled?http://earth911.com/news/2012/11/12/how-many-times-can-materials-be-recycled/paper-bales-our-flickr/

How much energy does recycling save?http://greenliving.nationalgeographic.com/much-energy-recycling-save-2363.html

Recycling factshttp://www.recyclingtown.com/http://www.recycling-revolution.com/recycling-facts.html

How to identify hazardous wastehttp://www.in.gov/idem/5043.htm#step3