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