Chapter 23 Solid and Hazardous Waste. Overview of Chapter 23 Solid Waste ▫Types of Solid Waste...
-
Upload
veronica-lyles -
Category
Documents
-
view
224 -
download
2
Transcript of Chapter 23 Solid and Hazardous Waste. Overview of Chapter 23 Solid Waste ▫Types of Solid Waste...
Chapter 23Solid and Hazardous Waste
Overview of Chapter 23
•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
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
Difficult to recycle
because of many
additives
Most environmental
ly harmful plastic; dioxins:
cancer and endocrine disrupter
Solution: phase out PVC use for other materials “PVC” or
“vinyl”
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
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
▫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:▫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
o Clay or Clay or plastic plastic lining lining bottombottom
o UnderneatUnderneath pipes h pipes collect collect leachateleachate
o Soil and Soil and clay cover clay cover (cap) when (cap) when at capacityat 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
o Special Problem of Tires• Cannot be melted and
reused for tires• Can be incinerated
or shredded• Mosquito breeding
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, NOHCl, SO2, NOXX)▫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 housingCancer-causing (carcinogen) waste (benzene)
found in basementInstrumental in leading to the development of
CERCLA (“superfund” – next slide)
Management of Hazardous Waste
1. 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
2. Comprehensive Environmental Response, Compensation, and Liability Act (1980) (CERCLA) aka “superfund” – pays for cleanup
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
States with the greatest number of sites
New Jersey (115)California (93)Pennsylvania (93)New York (86)Michigan (65)
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