Chapter 23 Solid and Hazardous Waste
Overview of Chapter 23 Solid Waste Waste Prevention Hazardous 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
Humans generate waste that other organisms cannot use
Plastic lunch bags Throw-away napkins Disposable diapers replaced cloth in the 60s Disposable plates and forks Larger items made NOT to last Packaging!!!
Past: broken bookcase wooden stool wood for fire
Solid Waste US generates more solid waste per capita than any other country 2.1kg per person per day (4 ½ lbs) Types of Solid Waste Municipal solid waste Solid material discarded by homes, office buildings, retail stores, schools, hospitals, prisons, etc Non-municipal solid waste Solid waste generated by industry, agriculture, and mining
Composition of Municipal Solid Waste
e-waste Small by weight, but effects are large Contain valuable metals: lead, mercury, cadmium Cathode ray tubes (CRT) (“hazardous waste”) More expensive to recycle than to go to landfill Some recycled waste goes to China: no protective clothing/respiratory gear
PVC: polyvinyl chloride Wire insulator Pipes Leather-like material clothes Water beds Shower curtains Pool toys Inflatable structures Releases dioxins when burned Most environmentally harmful plastic; dioxins: cancer and endocrine disrupter Solution: phase out PVC use for other materials Difficult to recycle because of many additives “PVC” or “vinyl”
Reduce Reuse Recycle
REduce Individual: print double sided, email assignments (don’t print), don’t print emails, downloading music and not buying CDs, less paper towels Corporations: less packaging that protects product equally
HW: identify a product with wasteful packaging Reducing Waste Purchase products with less packaging HW: identify a product with wasteful packaging
REuse Ideally requires no more energy input Newspapers for animal beds, wrapping paper Reuse coffee mug instead of styrofoam/paper cup. eBay, Craigslist, Freecycle Bottling factory: wash, sterilized, refilled
REcycle Convert materials into raw materials for some other purpose Closed-loop: recycle into same product (aluminum cans) – cheaper to recycle than to make new Open-loop: plastic soda bottle into polar fleece jacket, tires into playground Avoids landfill, but still requires raw material (petroleum) for new bottles
Requires more energy than reducing or reusing: cleaning, transporting, sorting Sometimes difficult to find buyers for glass and plastic 1/3 MSW in US recycled
Recycling Materials Every ton of recycled paper saves: 17 trees 7000 gallons of water 4100 kw-hrs of energy 3 cubic yards of landfill space
Recycling Recycling Plastic Recycling Glass Less expensive to make from raw materials Recycling Glass Costs less than new glass Can be used to make glassphalt (right)
Recycling Recycling Aluminum Making new can from recycled one costs far less than making a brand new one
Recycling Recycling Tires Few products are made from old tires Playground equipment Trashcans Garden hose Carpet
composting Pros: Other info: Diverts organic materials (food and yard waste) from landfills Space is saved and methane gas (from anaerobic respiration) is avoided Produces humus to enrich soil Other info: Turn frequently to aerate Worms can be used
Disposal of Solid Waste Three methods Sanitary Landfills Recycling Incineration
Sanitary Landfill NIMBY Problems: They fill up Methane gas production by microorganisms (MSW compacted into “cells” to save space) Greenhouse gas and explosive Can be captured to generate heat or electricity Contamination of ground water by leachate
Sanitary Landfill Clay or plastic lining bottom Underneath pipes collect leachate Soil and clay cover (cap) when at capacity
Sanitary Landfill Ideally: No metals (aluminum, copper, etc) –valuable and leach No organic matter (food scraps, yard waste) – source of methane No toxic material (household cleaners, oil-based paints, electronics) Glass and plastic only if can’t recycle Special Problem of Tires Cannot be melted and reused for tires Can be incinerated or shredded Mosquito breeding
Approximately the size of TEXAS North Pacific Gyre – collects vortex of garbage Approximately the size of TEXAS
Other than landfills, how else do we dispose of garbage???????
Incineration Pros: Volume of solid waste reduced by 90% Produces heat that can make steam to generate electricity Called waste-to-energy Produce less carbon emissions than fossil fuel power plants (right)
Incineration
Incinerator Problems Associated with Incineration Yields air pollution (HCl, SO2, NOX) Produce large amounts of ash Sent to landfill if safe (e.g.lacking lead) or used elsewhere (e.g. cement blocks) Sent to hazardous waste landfill if toxic Site selection often controversial, expensive (and then requires lots of MSW to be profitable, may reduce municipal push to recycle)
Integrated Waste Management
Hazardous Waste Any discarded chemical that threatens human health or the environment Reactive, corrosive, explosive or toxic chemicals Types of Hazardous Waste Dioxins PCBs (insulator in transformers) Radioactive waste See chart (right)
Love Canal, New York (1978-80) A hazardous waste landfill school and housing Cancer-causing (carcinogen) waste (benzene) found in basement Instrumental in leading to the development of CERCLA (“superfund” – next slide)
Management of Hazardous Waste Resource Conservation and Recovery Act (RCRA) (1976, 1984) – identifies what constitutes hazardous waste and provides guidelines regarding transporting and waste disposal; “cradle to grave”; keeps a record of hazardous waste to reduce illegal dumping Comprehensive Environmental Response, Compensation, and Liability Act (1980) (CERCLA) aka “superfund” – pays for cleanup
Management of Hazardous Waste States with the greatest number of sites New Jersey (115) California (93) Pennsylvania (93) New York (86) Michigan (65) Management of Hazardous Waste Cleaning up existing hazardous waste: superfund program 400,000 waste sites Leaking chemical storage tanks and drums (right) Pesticides dumps Piles of mining wastes
Cleaning –up hazardous waste Bioremediation: using microorganisms (little longer but cheap) – excellent for petroleum Phytoremediation: use plants and then plants disposed of at hazardous waste landfill Dig up contaminated soil and burn it Dilute soil: contaminate water, water shortage Vapor extraction (inject air in soil remove volatile compounds)
Management of Hazardous Waste Treatment of: (1) conversion to less hazardous materials (e.g. neutralize a corrosive acid with a base) (2) Incinerate/burn : dispose ash at special landfill (3) Hazardous waste landfill: several clay layers/heavy plastic liner on bottom Contents placed in containers Careful monitoring of nearby groundwater Final cover must limit liquids through landfill Another solution: use less hazardous waste (substitute with less harmful product) in the first place.
Hazardous Waste Landfill
Environmental Justice International Waste Management Developed countries sometimes send their waste to developing countries Less expensive than following laws within the country Basel Convention (1989) Restricts international transport of hazardous waste
Persistent organic pollutants Persist, bioaccumulate in tissue, biomagnify in food chain Stockholm Treaty on Persistent Organic Pollutants Include: PCB DDT dioxins