Environmental Science Unit 6 – Waste (STE 7th ed. Chapter 13)
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Transcript of Environmental Science Unit 6 – Waste (STE 7th ed. Chapter 13)
Environmental Science
Unit 6 – Waste(STE 7th ed. Chapter 13)
"Solid wastes are only raw materials we're too stupid to use."
Arthur C. Clarke
Where are we going?
1. Waste in Modern Societysolid waste, hazardous waste
2. Dealing with Wasteoptions, reducing, reusing, recycling
3. Recyclingtypes, benefits, issues
4. Managing Wastedetoxifying, burning, burying, exporting
5. Hazardous Waste
6. Achieving a low waste society
Question
‘The Throw-Away Society’
One country with 5 % of the world’s population produces 33% of the world’s solid waste…
Movie
1. Waste in Modern Society
• solid waste: any unwanted or discarded material that is not a liquid or gas;
• U.S. 5% of world population, generates 33% of solid waste, 10 billion metric tons/year
• 99% is industrial
+ hazardous waste
Municipal Solid Waste
• in U.S., 680 (1,500 lbs) kg/person/yr
• 57% dumped in landfills
• 16% burned in incinerators & waste–to–energy plants
• 27% recycled (1996)
U.S. MSW Disposal 1995-96 (Source, EPA)
Landfill57%
Composting or Recycling
27%
Incineration16%
High Waste Society
• 1,900 lbs of garbage per person (2-3 x most other developed countries)
• Containing:– Enough Al to rebuild the entire commercial airline fleet every 3
months– Enough tires a year to encircle the planet 3 times– 18 billion diapers, when linked end-to-end would reach to the moon
and back – 2 billion disposable razors, – 10 million computers and – 8 million TV’s 2.5 million non-returnable plastic bottles every hour– 14 billion catalogs and – 38 billion pieces of junk mail
China E-WasteChina Computer Waste
ABC 2006
E-Waste, A Growing Problem
• E-waste consists of toxic and hazardous waste such as PVC, lead, mercury, and cadmium
• The U.S. produces almost half of the world's e-waste but only recycles about 10% of it
E-Waste, A Growing Problem
Recycle Stuff We Leave Behind
ABC 2007
Dealing With Waste
• waste management Bury, burn or ship of to another state or country.
• waste prevention low waste approaches:
– 1) reduce,– 2) reuse,– 3) recycle & compost,– 4) chemically & biologically
treat– 5) bury
Views waste as a resource, or as harmful substances that we should not be using.60-80% of the waste could be eliminated. The remaining 20-40%
burned or buried.
Dealing with Solid Waste
The outlined schemes are currently reversed in the U.S.A. The major reason is that the cost of producing and dealing with the wastes is not included in the prices of products
Question
What are the three R’s?
Reduce
• decrease consumption
• redesign manufacturing processes to produce less waste
• produce durable goods that can be repaired or maintained
• eliminate unnecessary packaging
• promote consumer choice of green products
• institute "trash taxes" by charging for unnecessary waste
Reuse
• extends resource supplies, prevent pollution.
– refillable containers
• developing countries shifting to non–refillable containers
• various developed countries returning to refillable containers (e.g., Denmark banned non–refillable containers, Finland 95% refillable, Germany73% refillable)
• various states in U.S. require deposits; legislation strongly opposed by the bottle industry ("Keep America Beautiful")
• tires: retreads, construction, artificial reefs
• reusable cloth or string bags: clear choice
• paper & plastic bags: not clear– plastic bags less energy, degrade slowly & use non–renewable
resources– Many countries charge shoppers for plastic bags
• disposable vs. cloth diapers: not clear– cleaning cloth diapers uses large amounts of energy, produces air &
water pollution
• Reusing can be hazardous in developing countries for poor who scavenge in open dumps– They can be exposed to toxins or infectious diseases.
Recycle
• various kinds of reuse of resources– composting organic materials are broken down by
microorganisms to produce a humus-like material used to condition soilsBiodegradable material makes up 35% of MSW, only ~5% is composted in U.S. Compared with 17% in France and 10% Switzerland
– primary (closed loop): reusing waste materials to produce materials of the same type (e.g., newspaper to make newspaper)Reduces the amount of virgin material in a product by 20-90%
– secondary (open loop): using waste materials to produce different products (e.g., glass bottles to produce aggregate for roads)Reduces virgin material in a product by 25%
3 + 2 = 5 R’s
• Refuse: to buy items that we really don’t need
• Reduce: consume less and live a simpler and less stressful life by practicing simplicity
• Reuse: rely more on items that can be used over and over
• Repurpose: use something for another purpose instead of throwing it away
• Recycle: paper, glass, cans, plastics…and buy items made from recycled materials
• Follow the five Rs of resource use: Refuse, Reduce, Reuse, Repurpose, and Recycle.
• Buy products in concentrated form whenever possible.
• Read newspapers and magazines online.
• Use e-mail in place of conventional paper mail.
• Refill and reuse a bottled water container with tap water.
• Do not use throwaway paper and plastic plates, cups and eating utensils, and other disposable items when reusable or refillable versions are available.
• Buy things that are reusable, recyclable, or compostable, and be sure to reuse, recycle, and compost them.
• Rent, borrow, or barter goods and services when you can.
• Ask yourself whether you really need a particular item.
What Can You Do?
Solid Waste
Recycle Garbage Growth
CNN 2003
RecyclingSource: EPA MSW Generation, Disposal and Recycling in the USA: Facts and Figures for 2006
Recycling
• Recycled labels may be misleading?
• All recycled materials must be mixed with virgin material for strength
• 1998: 30% of MSW recycled or composted 96% of car batteries 43% of paper 42% of Al cans 40% of yard waste 27% of glass containers
Centralized Recycling vs. Source Separation
• source separation better economically & environmentally
• aluminum & paper have good markets;
• other materials often do not have good markets (e.g., glass, plastic)
• many communities established recycling centers; expected to pay for themselves; in general, not economically feasible
Aluminum
• recycling produces 95% less air pollution, 97% less water, & 95% less energy than mining & processing ore
• many environmentalists view cans as undesirable
• refillable glass or plastic bottles more energy–efficient & less polluting
The empty aluminum can is worth about 1 cent
Tossing away an aluminum can wastes as much energy as pouring out half of that can's volume of gasoline
Aluminum recycling rates
Paper
• easy to recycle, good market, & significant consumer demand
• recycling postconsumer waste prevents disposal by incineration or land fills
• recycling preconsumer waste (scraps & cuttings from paper & printing plants) has always been done, & is therefore just a marketing ploy
Newspaper
• uses 30–64% less energy• reduces air pollution by pulp mills 74–95%• lowers water pollution by 35%• prevents groundwater contamination by toxic ink leaching
from landfills• conserves large amounts of water• saves landfill space (~40% of landfills)• creates five times more jobs• saves money
Plastics
• Chemically and economically difficult
• must be sorted by type (according to resin);
• current price of virgin plastic resins is about 40% lower than recycled resins
• PET, used for plastic beverage bottles, prices competitive
• often used in secondary recycling,– e.g., construction materials
& plastic bags made from beverage bottles
Recycle Trash Traders – Secondary Recycling
CNN 1998
Recycle Bottle Backlash
ABC 2007
Recycling
• Reuse and recycling are hindered by prices of goods that do not reflect their harmful environmental impacts, too few government subsidies and tax breaks, and price fluctuations.
Composting
• Composting biodegradable organic waste mimics nature by recycling plant nutrients to the soil.
Enriches soils - Reduce or eliminate the need for chemical fertilizers, promotes higher yields of agricultural crops.
Remediates contaminated soils – removes VOC’s and heavy metals
Prevents pollution – prevents formation of methane and leachate in landfills
Important part of economy
Source separation is inconvenient for some people
Reduces profits from landfills and incinerators
Reduces air and water pollution
Saves energy
Reduces mineral demand
Reduces greenhouse gas emissions
Reduces solid waste production and disposal
Helps protect biodiversity
Can save money for items such as paper, metals, and some plastics
Does not save landfill space in areas with ample land
May lose money for items such as glass and most plastic
DisadvantagesAdvantages
Trade-Offs
Recycling
4. Managing Waste
• detoxification• incineration - reduces quantity; causes air pollution;• land disposal - burial or impoundment
– sanitary land fill stores solid wastes in compacted layers that are covered daily with layers of clay or plastic foam
– most U.S. hazardous waste disposed by deep–well injections, surface impoundment, & state–of–the–art landfills
• exporting to other countries and ocean dumping
Incineration
‘Waste to energy’ incinerator
NIMBY
Can be reduced by prior removal plastics and metals
LandfillsGarbage Graveyard
• US 54%, UK 90 %, Canada 80 %, Japan 15 %, Switzerland 12 %
• Site is chosen based on geology• New layers are lined with clay and plastic• Liner at the base collects leachate
– Leachate = rainwater contaminated as it percolated through the site
– Pumped and treated– 85 % unlined
• Landfill gas = produced by biological activity on organic material (methane)
• 40% is paper!
Sand
When landfill is full,layers of soil and clayseal in trash
Methane storageand compressorbuilding
Leachatestoragetank
Leachatemonitoringwell
Groundwatermonitoringwell
Electricitygeneratorbuilding Leachate
treatment system
Methane gasrecovery well
Compactedsolid waste
Leachatepipes
Leachate pumpedup to storage tankfor safe disposal
GroundwaterClay and plastic liningto prevent leaks; pipescollect leachate frombottom of landfill
Topsoil
SandClaySubsoil
Probes todetectmethaneleaks
Garbage
Garbage
Syntheticliner
Sand
Clay
Pipes collect explosive methane as used as fuel to generate electricity
No open burning
Trade-Offs
Sanitary Landfills
Advantages Disadvantages
Eventually leaks and can contaminate groundwater
Discourages recycling, reuse, and waste reduction
Slow decompositionof wastes
Groundwater contamination
Releases greenhouse gases (methane and CO2)unless they are collected
Air pollution from toxic gases and volatile organiccompounds
Dust
Noise and traffic
No shortage of landfill space in many areas
Filled land can be used for other purposes
Can handle large amounts of waste
Can be built quickly
Low operating costs
Low groundwaterpollution if sited properly
Little odor
Exporting
• Export of hazardous waste banned under the 1992 Basel convention
• Does not include radioactive waste
• ‘garbage Imperialism – poorer neighbourhoods more likely to have dumps, incinerators and other locally unwanted land uses (LULU’s)
What Harmful Chemicals Are in Your Home?
• Glues and cements
• Dry-cell batteries (mercury and cadmium)
• Rust inhibitor and rust remover
• Brake and transmission fluid
General
Cleaning
• Battery acid
• Wood preservatives
• Stains, varnishes, and lacquers
Automotive
• Gasoline• Used motor oil
Paint
• Latex and oil-based paints• Paint thinners, solvents, and strippers
Gardening
• Pesticides• Weed killers• Ant and rodent
killers
• Antifreeze
• Flea powders
• Disinfectants
• Septic tank cleaners• Spot removers
• Drain, toilet, and window cleaners
• Artist paints and inks
• Solvents
5. Hazardous Waste
Definition in U.S.:
• fatal at low doses• toxic: contains one or more
of 39 toxic, carcinogenic, mutagenic, or teratogenic compounds that exceed established limits
• flammable: (gasoline, paints, solvents...)– or
• reactive/unstable: can explode or release toxic fumes
Definition contains both toxic and hazardous materials
• many important omissions:– radioactive wastes, hazardous & toxic wastes discarded by
households, mining wastes, oil & gas drilling wastes, liquid waste containing organic compounds, cement kiln dust, wastes from small businesses & industries
• US. produces 6 billion tons per year, or 75% of the world’s hazardous waste. Only 5% is legally defined as hazardous. 95% of the country’s hazardous output is unregulated by law.
• environmentalists call this "linguistic detoxification“
• The two largest classes of hazardous wastes are organic compounds (e.g. pesticides, PCBs, dioxins) and toxic heavy metals (e.g. lead, mercury, arsenic)
Lead
• acute lead poisoning causes severe neurological problems; children who survive acute lead poisoning can display decline in mental capabilities, palsy, paralysis, blindness, & mental retardation
• chronic lead poisoning results because of bioaccumulation; especially threat to children
• exposure in U.S. decreased due to regulation that phased out lead in gasoline & solder
• other sources include old paint, plumbing, & ceramic glazes
Chlorine, Dioxin and PCB’s
• chlorine used to produce plastics (PVC), solvents, bleach, paper & wood pulp, purify water, & produce household bleaching agents
• many chlorine containing compounds are persistent, accumulate in body fat, & cause serious health problems
• less harmful & affordable alternatives (e.g., ozone to purify water)
Case Study: Love Canal
• Between 1842-1953, Hooker Chemical sealed multiple chemical wastes into steel drums and dumped them into an old canal excavation (Love Canal)
• In 1953, the canal was filled and sold to Niagara Falls school board for $1
• The company inserted a disclaimer denying liability for the wastes
Case Study: Love Canal
• In 1957, Hooker Chemical warned the school not to disturb the site because of the toxic waste.– In 1959 an elementary school, playing
fields and homes were built disrupting the clay cap covering the wastes.
– In 1976, residents complained of chemical smells and chemical burns from the site.
Love Canal
President Jimmy Carter declared Love Canal a federal disaster area
The area was abandoned in 1980 (left)
Year
1942-53 Hooker Chemicals and Plastics dump steel drums containing ~200 chemicals into an old canal near Niagra Falls.
1953 Canal is sealed and covered with clay and a layer of soil. Sold to the local school board for $1. Deeds contained a disclaimer denying liability for injury.
1957 Hooker warns school board not to disturb the site due to danger from toxic waste.
1959 By this time a school, play area and ~1000 homes had been built around the site. New roads and sewers disturb the clay cap.
1960’s Expressway blocks groundwater from migrating to the river. Contaminated water builds up inside the site and eventually over-flows
1976 Residents complaints about ‘chemical smells’ and burns their children receive whilst playing are ignored by government officials.
1977 Chemicals begin to leak from corroded drums into sewers, gardens, basements and the school playground.
1978 School is closed after protests from residents. 239 homes closest to the dump were demolished.
1980 President Carter declares the area a federal disaster zone. Remaining families are relocated. Residents of all but 72 homes move out.New clay cap is added and a drainage system is
installed that pumps waste to a treatment plant.US Government identifies 248 chemicals in the dump site
1990 EPA declares the area safe. Renamed to ‘Black Creek Village’.
1994 OxyChem (new owner of Hooker) agrees to $98 million settlement to NY State
1999 OxyChem agrees to reimburse the federal government and NY State $7.1 million.
Health Effects
• Although it is always very difficult to prove that a hazardous waste dump is the only cause for health problems, Love Canal seemed to be ripe with mysterious illnesses,
• High rates of:-miscarriages, -birth defects, -cancer
• as well as certain diseases of the liver and kidneys, organs where chemicals are concentrated by the body to detoxify.
• Subsequent studies (termed epidemiological studies) showed that these health effects were also found in people whose homes were nearby.
Hazardous Regulations
Two major U.S. laws:• 1. Resource Conservation & Recovery Act (RCRA) (1976,
amended 1984)
EPA identifies hazardous wastes & sets standards
requires permits for more than 100 kilograms (220 pounds)
"cradle to grave" tracking
Superfund
2. Superfund Act (1980, amended 1986 & 1990) – established $16.3 billion Superfund to identify &
clean up abandoned hazardous waste dump sites such as Love Canal
– cleanup based on "polluter pays principle"– currently 1,360 sites on National Priority List– ‘right to know’ – Toxic Release Inventory
Disposal
• ‘recycling’– Asphalt or concrete for building highways– Mixing of haz waste with minerals to produce fertilizer
• Deep-well: 60% of US Haz Waste– Pump into dry rock beneath surface– Isolated from ground water– Cheap
• Surface impoundment– Ponds, pits or lagoons– 70% have no liners– Groundwater problems– VOC’s evaporate
• Land-fills: 5%– Sealed in drums and buried– Monitoring
• Underground storage
Liners leak
Transport accidents
Underground Storage
Remediaton
• Accumulation of chemicals by plants
6. Achieving a Low Waste Society
• reducing, reusing, & recycling ("the three R's") most effective means, in that order
• consumer choice of quality "green" products, that last a long time, have minimal environmental impacts during manufacture, & have parts that can be reused or recycled
• low–waste practices "built into the system" by redesigning manufacturing processes & refocusing research & development efforts
• grassroots efforts to support environmentally sound practices for incinerators, landfills, & treatment plants for hazardous & radioactive wastes