1. Waste Generation and Waste Disposal
Chapter 16
Waste Generation and Waste Disposal

2. Municipal Solid Waste
Refuse collected by municipalities from households, small businesses, and institutions such as schools, prisons, municipal buildings and hospitals.

4. Composition of Municipal Solid Waste
31% - paper
33%- organic materials (yard waste, food scraps, wood)
12%- plastic
18%- durable goods (appliances, tires)

5. MSW 1.5% of total waste stream
33% of MSW is recycled or composted, 55% landfilled, 15% burned in incinerator
3M company reduced solid waste by 70%, saved 750 million

8. E-Waste
Electronic waste (E-waste) televisions, computers, cell phones that contain toxic metals.

9. Reduce, Reuse, Recycle Reduce- waste minimization or prevention
Reuse- reusing something like a disposable cup more than once
Recycle- materials are collected and converted into raw materials and then used to produce new objects

10. Ways to Reduce Reduce use Redsign manufacturing process
Trash taxes (Denmark)
Pay as you throw (trash bags)

11. Reuse
Denmark, Finland, and Prince Edward Island have banned beverage containers that can’t be reused
San Francisco has banned the use of plastic shopping bags. Residents are encouraged to use cloth.

12. Solid Waste Problems Plastic vs paper grocery bags
Less energy, less landfill space vs renewable resource, less danger if swallowed (cloth is best)
Disposable vs cloth diapers
Manufacuring, landfill vs cleaning effects
Tires (250 million discarded each year)
2.5 to 4 billion used tires are in US

13. Recycling MSW: 50% recycled in Switzerland and Japan, 33% in US
Primary (closed loop) vs secondary recycling (playground mulch from tires)
Paper can be downgraded (writing paper to newsprint to toilet paper)

14. Recycling paper High quality is available
2000, US recycled 49% of wastepaper
Chlorine used to bleach, hydrogen peroxide and ozone are replacing chlorine
Recycled from preconsumer vs post consumer waste

15. Recycling (cont) Germany: take back packaging
Netherlands: no pckg in landfill
Sell service instead of goods (Xerox)

16. Materials-Recovery Facilities (MRFs)
Large scale (480 in US)
Separate, recycle or burn (electricity)
Source separation (home or business) has advantages
Single stream recycling is done at Archmere
Ash to landfill
Aluminum is valuable

17. Plastics 4 % of US plastic is recycled
Difficult to recycle b/c many different, incompatible layers of polymers are used (PET [polyethylene terephthalate] in 2 liter bottles has one polymer, 20% is recycled)
Coca-Cola announced goal to recycle 100% of PET bottles

18. Composting
Compost- organic material that has decomposed under controlled conditions to produce an organic-rich material.

19. Composting
Turn periodically to raise temp, kill pathogens and weed seeds
Siting plants is difficult (NIMBY)

21. Figure 21.10
Backyard composter drum in which bacteria convert kitchen waste into rich compost. When the compost is ready, the device can be wheeled out to the garden or flowerbeds.
Fig , p. 570

22. Worm Composter
Uses worms to aerate organic material

23. Landfills
Sanitary landfills- engineered ground facilities designed to hold MSW with as little contamination of the surrounding environment as possible.
Leachate- the water that leaches through the solid waste and removes various chemical compounds with which it comes into contact.

25. When landfill is full, layers of soil and clay seal in trash
Topsoil
Sand
Electricity generator building
Clay
Leachate treatment system
Garbage
Methane storage and compressor building
Probes to detect methane leaks
Pipes collect explosive methane for use as fuel to generate electricity
Methane gas recovery well
Leachate storage tank
Compacted solid waste
Figure 21.15
Solutions: state-of-the-art sanitary landfill, which is designed to eliminate or minimize environmental problems that plague older landfills. Since 1997, only modern sanitary landfills are allowed in the United States. As a result, many small, older local landfills have been closed and replaced with larger regional landfills. Question: How do you think sanitary landfills could develop leaks of toxic liquids?
Leachate pipes
Groundwater monitoring well
Leachate pumped up to storage tank for safe disposal
Garbage
Sand
Synthetic liner
Leachate monitoring well
Sand
Groundwater
Clay and plastic lining to prevent leaks; pipes collect leachate from bottom of landfill
Clay
Subsoil

26. Sanitary Landfill 54% of waste in US is landfilled
Sand, clay layers around synthetic liner
Leachate is pumped from bottom, sent to water treatment plant
Except for Phila, NYC no shortage of space
Methane (anaerobic decomp) can be collected (Tullytown, PA)

29. Incineration
Incineration- the process of burning waste materials to reduce its volume and mass and sometimes to generate electricity and heat.

30. Incinerators Temperatures up to 3,600oF 16% of MSW is burned
170 incinerators in US

31. Wet scrubber Waste pit Bottom ash Dirty water
Electricity
Smokestack
Steam
Turbine
Crane
Generator
Wet scrubber
Furnace
Boiler
Electrostatic precipitator
Waste pit
Water added
Bottom ash
Dirty water
Conveyor
Figure 21.13
Solutions: a waste-to-energy incinerator with pollution controls. It burns mixed solid wastes and recovers some of the energy to produce steam used for heating or producing electricity. Question: Would you invest in such a project? Why or why not?
Fly ash
Ash for treatment, disposal in landfill, or use as landfill cover
Fig , p. 575

32. Hazardous Waste
Hazardous waste- liquid, solid, gaseous, or sludge waste material that is harmful to humans or ecosystems.
Collection sites for hazardous waste must be staffed with specially trained personnel.
Hazardous waste must be treated before disposal.

33. Laws
Resource Conservation and Recovery Act (RCRA)- designed to reduce or eliminate hazardous waste. Also know as “cradle-to-grave” tracking.
RCRA ensures that hazardous waste is tracked and properly disposed of.

34. RCRA Resource Conservation and Recovery Act, 1976, amended in 1984
Requires EPA to identify hazardous waste and set standards for management by states
Firms with more than 220 lbs need permit stating how waste is managed
Permit holders use “cradle to grave” system

35. Superfund
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)- also know as “Superfund”.
Puts a tax on the chemical and petroleum industries. This revenue is used to cleanup abandoned and nonoperating hazardous waste sites where a responsible party cannot be found.
Requires the federal government to respond directly to the release of substance that may pose a threat to human health or the environment

36. Superfund Act
Comprehensive Environmental Response, Compensation, and Liability Act, 1980
National Priorities List
Polluter pays principle
Joint and several liability
321 sites cleaned up, average $20 million per site

37. Figure 21.26
Leaking barrels of toxic waste at a Superfund site in the United States. This site has since been cleaned up.
Fig , p. 583

38. Brownfields
Contaminated industrial or commercial sites that may require environmental cleanup before they can be redeveloped or expanded.
Old factories, industrial areas and waterfronts, dry cleaners, gas stations, landfills, and rail yards are some examples.

39. Brownfields
Abandoned industrial and commercial sites, usually contaminated (factories, gas stations, etc)
450, ,000 in US, 40k redeveloped
Clean up efforts are hampered by fear of liability
Congress and many states have passed laws limiting liability of lenders and developers

40. Integrated Waste Management
A method that seeks to develop as many options as possible, to reduce environmental harm and cost.
Reduction, recycling, composting, landfills, and incineration are some ways IWM is utilized.

41. Integrated Management of Hazardous Waste
US National Academy of Sciences offers three priorities for dealing with haz mat
Produce less of it
Convert it to less hazardous substances
Put rest in long-term, safe storage
1/3 of hazardous waste produced in Europe is sold as raw materials to other industries
In US, only 10% is recycled

42. Exporting Hazardous Waste
Basel Convention on Hazardous Waste
1995 amended version, bans export of hazardous waste from developed to developing countries
Created due to Khian Sea waste disposal incident (Philadelphia incinerator ash)
US has signed but not ratified

43. Figure 21.18
Solutions: phytoremediation. Various types of plants can be used as pollution sponges to clean up soil and water and radioactive substances (left), organic compounds (center), and toxic metals (right). (Data from American Society of Plant Physiologists, U.S. Environmental Protection Agency, and Edenspace)
Fig , p. 579