Chapter 24 Solid and Hazardous Waste

Overview of Chapter 24 Solid Waste – Types of Solid Waste Waste Prevention – Reducing the Amount of Waste – Reusing Products – Recycling Materials Hazardous Waste – Types of Hazardous Waste – Management of Hazardous Waste Environmental Justice

Solid Waste US generates more solid waste per capita than any other country – 2.1kg per person per day Examples of publicized solid waste disposal issues – Break of Dawn – Khian Sea Waste generation – unavoidable consequence of prosperous, high-tech, industrial economies

Solid Waste Types of Solid Waste – Municipal solid waste Solid material discarded by homes, office buildings, retail stores, schools, hospitals, prisons, etc Relatively small portion of solid waste produced – Non-municipal solid waste Solid waste generated by industry, agriculture, and mining

Composition of Municipal Solid Waste

Disposal of Solid Waste Three methods – Sanitary Landfills – Incineration – Recycling

Sanitary Landfill o Compacting and burying waste under a shallow layer of soil o Most common method of disposal o No pollute surface and groundwater… o Image o Tipping fees and export o Ideal location factors

Sanitary Landfill Problems – Methane gas production by microorganisms – Contamination of surface water & ground water by leachate – Not a long-term remedy – capacity is almost reached – Few new facilities being opened Bigger though – Closing a full landfill is very expensive

Sanitary Landfill Special Problem of Plastic – Much of plastic is from packaging – Chemically stable and do not readily break down and decompose – How can you reduce plastic waste? Special Problem of Tires – Cannot be melted and reused for tires – Made from materials that cannot be recycled – Problem? Solution?

Incineration Volume of solid waste reduced by 90% Produces heat that can make steam to generate electricity – Produce less carbon emissions than fossil fuel power plants (right) Some materials separated out before incineration Best materials?

Incineration Types of Incinerators – Mass burn (next slide) – burns solid waste designed to recover energy from combustion – Modular – burns solid waste smaller, less expensive – Refuse-derived - only combustible portion of solid waste burned

Mass Burn Incinerator

Incinerator Problems Associated with Incineration – Yields air pollution, including… Pollution control devices, include: – Lime scrubbers – Electrostatic precipitators – Produce large amounts of ash – 2 kinds – Site selection often controversial

Composting Includes: – Food scraps – Sewage sludge – Agricultural manure – Yard waste Reduces yard waste in landfills Can be sold or distributed to community

Waste Prevention Three Goals – (1) Reduce the amount of waste – (2) Reuse products – (3) Recycle materials

Reducing Waste Source reduction – Products are designed and manufactured in ways that decrease the volume of solid waste in the waste stream – Accomplished by… Pollution Prevention Act (1990) Dematerialization – Progressive decrease in the size and weight of a product as a result of technological improvements

Reducing Waste Just something to think about…

Reusing Products Focus – refilling glass beverage bottles – In order for bottle to be reused, it must be thicker and heavier Heavier glass that costs more = higher cost of product Japan recycles almost all bottles – Reused 20 times Ecuador – bottles may remain in use for 10+ years

Recycling Materials Every ton of recycled paper saves: – 17 trees – 7000 gallons of water – 4100 kwatt-hrs of energy – 3 cubic yards of landfill space Recycle – Glass bottles, newspapers, steel cans, plastic bottles, cardboard, office paper

Recycling Recycling has environmental costs: – Uses energy – Generates air pollution Recycling programs increased dramatically during 90s but leveled off in early 2000s Materials recovery facility – hand sorted or separated using variety of technologies; then prepared for remanufacturing – US currently recycles ~32% of its municipal solid waste, including yard trimmings In some areas it is not economically feasible to recycle

Recycling Recycling Paper – US recycles 50% – Many developed countries are higher – why? Recycling Glass – US recycles 25% – Costs less than new glass – Cullet is… – Can be used to make glassphalt (right)

Recycling Recycling Aluminum – Making new can from recycled one costs less than making a brand new one and uses 1/20 energy Recycling Metals other than Aluminum – Lead, gold, iron, steel, silver and zinc – Metallic composition is often unknown Makes recycling difficult – Economy has influence on what is recycled and what is not – exception steel

Recycling Recycling Plastic – Less than 20% is recycled Why so little? – Polyethylene terphthalate (PET) – plastic used in soda bottles – Polystyrene – example of a plastic that has a great recycling potential but is currently not recycled – Many kinds of plastic present a challenge in recycling – Possible products from recycled plastic? “plastic lumber”

Recycling Recycling Tires – Few products are made from old tires Playground equipment Trashcans Garden hose Carpet Roofing materials – 36% of tires are currently recycled to make other products

Integrated Waste Management Integrated waste management – combination of the best waste management techniques into a consolidated, systems-based program to deal effectively with solid waste – Includes the 3 R’s of waste prevention – reduce, reuse, recycle

Hazardous Waste Any discarded chemical that threatens human health or the environment – Reactive, corrosive, explosive or toxic chemicals Lets talk about the Love Canal… Types of Hazardous Waste – Dioxins – PCBs – Radioactive waste

Dioxins Dioxins – group of 75 similar chemical compounds formed as unwanted by-products during combustion of chlorine compounds Known sources – mainly medical waste/municipal waste incinerators Are emitted as smoke – How does it get into human bodies? Effects of dioxins? – Known to cause several kinds of cancer in lab animals – data inconsistent if cause cancer in humans EPA opinion – Concerns of effects on human reproductive, immune and nervous systems

PCBs Polychlorinated biphenyls (PCB) – group of 209 industrial chemicals composed of carbon, hydrogen, and chlorine – Characteristics… Toxicology tests on animals – PCBs harm skin, eyes, reproductive organs, and gastrointestinal system – Endocrine disruptors – interfere with hormones released by the thyroid gland – Studies in children exposed to PCBs before birth – PCBs may be carcinogens according to some studies Chemically stable – resist chemical and biological degradation Human exposure from… Why are PCBs a problem now if use is banned in US? Effective ways to destroy PCBs – high temperature incineration – Also several bacteria can degrade PCBs

Case-In-Point Hanford Nuclear Reservation Tons of highly radioactive solid and liquid wastes were stored or dumped into trenches, pits, tanks, ponds, and underground cribs in a total of 1700 waste cites – Standard practices at the time Cleanup issues…

Management of Hazardous Waste Chemical accidents – National Response Center notified – Typically involves oil, gasoline or other petroleum spill – Chemical safety programs… Current Management Policies – Resource Conservation and Recovery Act (1976, 1984) – Comprehensive Environmental Response, Compensation, and Liability Act (1980)

Management of Hazardous Waste - CERCLA Cleaning up existing hazardous waste: superfund program – 400,000 waste sites – Leaking chemical storage tanks and drums (right) – Pesticides dumps – Piles of mining wastes Must be cleaned up

Management of Hazardous Waste Superfund National Priorities List – 2006: 1558 sites on the list – States with the greatest number of sites New Jersey (115) California (93) Pennsylvania (93) New York (86) Michigan (65) Shared responsibility for cleanup CERCLA is a deterrent to further polluting

Management of Hazardous Waste Biological Treatment of Hazardous Chemicals – Bioremediation – using bacteria Pros/cons? – Phytoremediation – using plants Pros/cons? Management the Waste we are Producing Now (be able to elaborate…) – (1) source reduction – (2) conversion to less hazardous materials – (3) long-term storage (image next slide)

Management of Hazardous Waste Hazardous Waste Landfill

Environmental Justice Studies of hazardous waste facilities near poor, minority neighborhoods – Problems… Environmental Justice and Ethical Issues – Right of every citizen, regardless of age, race, gender, social class, to adequate protection from environmental hazards – Fundamental human right – Grassroots campaign Mandating environmental Justice- Federal Level – Clinton – NRC

Environmental Justice International Waste Management – Developed countries sometimes send their waste to developing countries Less expensive than following laws within the country Controversial aspect of waste management – Basel Convention (1989) - allows countries to export hazardous waste only with the prior informed consent of importing country as well as any country that waste passes thru in transit 1995 – amended to ban export of ANY hazardous waste from industrialized to developing nations US ratified??