17 lecture presentation lecture will help you understand: • the types of waste we generate •...
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Chapter
17
Lecture Presentations prepared byReggie Cobb
Nash Community College© 2015 Pearson Education, Inc.
Managing Our Waste
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This lecture will help you understand:
• The types of waste we generate • Managing waste • The scale of the waste dilemma • Conventional waste disposal • Ways to reduce waste • Industrial solid waste
management • Managing hazardous
waste
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Central Case Study: A Mania for Recycling on Campus• In 2001, Ohio University and Miami University of
Ohio competed in a 10-week recycling event • The first Recyclemania
• In 2014, 461 colleges competed for many awards
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Central Case Study: A Mania for Recycling on Campus (cont’d)• Recyclemania is the biggest of a growing number of
campus competitions in the name of sustainability • The Campus Conservation Nationals is gaining
momentum • Students on campuses across the country compete to
see who can save the most water and energy • 109 colleges participated
• Campus sustainability is thriving • Students, faculty, staff, and administrators are doing the
right things • Competing in these competitions adds to the fun
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Approaches to waste management
• Waste • Any unwanted material or substance that results from a
human activity or process • Municipal solid waste
• Nonliquid waste from homes, institutions, and small businesses
• Industrial solid waste • From production of goods, mining, agriculture, petroleum
extraction and refining • Hazardous waste
• Solid or liquid waste that is toxic, chemically reactive, flammable, or corrosive
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We have several ways to manage waste
• Minimize the amount of waste generated (source reduction)
• The preferred approach • Recover waste materials
and recycle them • Dispose of waste safely
and effectively • Waste stream
• The flow of waste as it moves from its sources to its disposal destinations
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Municipal solid waste
• Most U.S. municipal solid waste (“trash” or “garbage”) consists of paper, yard debris, food scraps, and plastics
• Food scraps and plastics are the largest components • Most municipal solid waste comes from packaging
and nondurable goods (discarded after a short time of use)
• As we get more goods, we generate more waste • U.S. citizens generate 7.1 lb/person each day • Critics label the U.S. the “throwaway society” • U.S. waste decreased slightly from 2005 to 2012
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Developing nations are producing waste
• Consumption is greatly increasing in developing nations
• Rising standard of living, more packaging, poor-quality goods
• Wealthy consumers discard items that can still be used
Poor people support themselves by selling items they scavenge from dumps
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Disposal methods have improved
• Wealthier nations invest in waste collection and disposal
• Efforts minimize impacts on health and the environment • Recycling and composting are decreasing pressure on
landfills
In 2012 in the U.S., 35% of waste was recycled or composted
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Landfills provide our main method of disposal
• Sanitary landfills • Waste buried in the ground or piled in large mounds to
prevent contamination and health threats • U.S. landfills must meet the EPA’s national standards
under the Resource Conservation and Recovery Act (RCRA) of 1976
• Waste is partly decomposed by bacteria and compresses under its own weight to make more space
• Soil layers reduce odor, speed decomposition, reduce infestation by pests
• Closed landfills must be capped and maintained
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Landfills provide our main method of disposal (cont’d)• Leachate
• Liquid from trash dissolved by rainwater • It is collected and
treated in landfills • Collection systems
must be maintained for 30 years after a landfill is closed
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Frequently Asked Question
• How much does garbage decompose in a landfill?
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Landfills have drawbacks
• Despite improved technology, liners can be punctured
• Leachate collection systems won’t be kept up • It takes decades for waste to decay • The not-in-my-backyard (NIMBY) syndrome:
residents don’t want landfills in their areas • Wealthy, educated people have the political clout to
prevent landfills from being sited in their neighborhoods • Landfills are disproportionately sited in poor and minority
communities
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Landfills can be transformed after closure
• In 1988, the U.S. had 8000 landfills • Today there are fewer than 2000, but they are large
• Cities have converted closed landfills into public parks, stadiums, gardens, wetlands, and festival events
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Weighing the Issues
• Environmental Justice? • Do you know where your trash goes? • Where is your landfill or incinerator located? • Are people who live closest to the facility wealthy, poor, or
middle class? • What race or ethnicity are they? • Do you know whether the people of this neighborhood
protested against the introduction of the landfill or incinerator?
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Incinerating trash reduces pressure on landfills
• Incineration • A controlled process that burns garbage at very high
temperatures • Metals are removed, and the rest is burned in a furnace • The remaining ash is toxic and must be disposed of in a
hazardous waste landfill • Hazardous emissions are created and released
• Scrubbers • Chemically treat emissions to remove hazardous
chemicals and neutralize acidic gases • Fly ash – particulate matter that can be very toxic • Baghouse – huge filters that physically remove fly
ash
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We can gain energy from trash
• Incineration reduces the volume of waste and can generate electricity
• Waste-to-energy (WTE) facilities • Use the heat produced by waste combustion to create
electricity • Landfill gas
• Bacterial decomposition creates a mix of gases that consists of 50% methane
• Can be collected, processed, and used like natural gas
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Reducing waste is our best option
• Source reduction • Preventing waste in the first place • Avoids costs of disposal and recycling • Helps conserve resources and minimizes pollution • Can save consumers and businesses money
• Most waste consists of materials used to package goods
• To reduce waste, use minimal or recyclable packaging • Buy unwrapped fruit and vegetables • Reduce the size or weight of goods and materials • Choose products that motivate producers to create
longer-lasting goods
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Reducing waste is our best option (cont’d)
• Some local governments are trying to reduce plastic bags
• Grocery bags can take centuries to decompose • They choke and entangle wildlife and cause litter • 100 billion of them are discarded each year in the U.S.
• Many governments have banned nonbiodegradable bags
• Tax on bags gives financial incentives to use other bags
• Consumers bring their own bags
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Reuse is a main strategy to reduce waste
• Actions we all can take to reduce the waste we generate:
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Composting recovers organic waste
• Composting • The conversion of organic waste into mulch or humus
through natural decomposition • It can be used to enrich soil
• Home composting • Householders place waste into composting piles,
underground pits, or specially constructed containers • Heat from microbial action builds up and spurs
decomposition • Earthworms, bacteria, and other organisms convert waste
into high-quality compost
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Composting recovers organic waste (cont’d)
• College campus composting programs • Ball State University, Indiana
• Shreds surplus furniture and wood pallets to make mulch to nourish on campus plants
• Ithaca College, New York • Composts 44% of its food waste / saves $11,500 disposal fees • Plantings also grow better with the compost mix
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Composting recovers organic waste (cont’d)
• Municipal composting programs • These programs divert food and yard waste from the
waste stream to central composting facilities • People can use the mulch in gardens and landscaping
• Half of U.S. states now ban yard wastes from the municipal waste stream
• Accelerating the move to composting
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Recycling consists of three steps
• Step 1: collection and processing of recyclable materials through curbside recycling or designated locations
• Materials recovery facilities (MRFs): workers and machines sort, clean, shred, and prepare items
• Step 2: using recyclables to produce new goods • Glass, metal, paper, plastics use recycled materials
• Step 3: consumers buy goods made from recycled materials
• Incentives for further recycling • Facilities are built or expanded
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Recycling has grown rapidly
• 9000 recycling programs serve 50% of Americans • U.S. recycling rates vary
• Depending on the product and state • Businesses see that they can save money • Entrepreneurs can start
new businesses
The U.S. recycles 26% of its waste stream
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Recycling has grown rapidly (cont’d)
• Recycling rates vary greatly depending on the product or material
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Recycling has grown rapidly (cont’d)
• Many college students are getting involved in Recyclemania, “trash audits,” and “landfill on the lawn”
• Louisiana State University recycled 68 tons of refuse • University of North Carolina at Greensboro
performed a trash audit to show how many recyclable items are thrown away needlessly
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Recycling has grown for many reasons
• Municipalities want to reduce waste • The public takes satisfaction in recycling • Recycling may not be profitable, however
• To collect, sort, and process materials is expensive • The more material that is recycled, the lower the price • Transportation costs to recycling facilities may be high
• But market forces do not take into account the health and environmental effects of not recycling
• Recycling offers enormous savings in energy and materials
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The Science Behind the Story
• Tracking Trash • Researchers from the SENSEable City Lab at
Massachusetts Institute of Technology (MIT) placed tracking devices on various kinds of trash in New York City and Seattle
• Movements of the items were tracked
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The Science Behind the Story (cont’d)
• Tracking Trash • Hazardous waste items and electronic waste items
tended to travel farthest because they were sent to special facilities for handling
• This raises the question, of whether special handling is worthwhile, given the impacts of extra gasoline use and greenhouse gas emissions required
• These data will be used to improve the ways we handle waste
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Weighing the Issues
• Costs of Recycling and Not Recycling • Should governments subsidize recycling programs even if
they are run at an economic loss? • What types of external costs do you think would be
involved in not recycling aluminum cans? • Do you feel these costs justify sponsoring recycling
programs even when they are not financially self-supporting?
• Why or why not?
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We can recycle materials from landfills
• Businesses are weighing the benefits of salvaging materials in landfills that can be recycled
• Metals (steel, copper) • Organic waste for compost • Wastes can be incinerated in WTE facilities • Harvesting methane from open dumps (Asia, Africa)
• But costs and regulatory requirements have made investing in landfill mining risky
• Rising prices and better technologies will change this
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Financial incentives help address waste
• “Pay-as-you-throw” approach: residents are charged according to how much trash they put out
• The less waste, the less a person has to pay • Bottle bills
• Consumers receive a refund for returning used bottles and cans to stores
• These bills are effective and popular • Container litter is reduced 69–84% • Total litter is reduced by 30–64% • States are beginning or expanding their programs
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Industrial solid waste
• Industrial solid waste • Is not municipal or hazardous waste • Comes from factories, mining, agriculture, petroleum
extraction, etc. • U.S. industries generate 7.6 billion tons of waste per
year • 97% is wastewater
• The federal government regulates municipal solid waste
• States and local governments regulate industrial solid waste (with federal guidance)
• State and local rules are less strict than federal rules
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Regulation and economics each influence industrial waste generation• Most methods and strategies of waste disposal,
reduction, and recycling are similar to those for municipal solid waste
• Industries may not be required to have permits or install liners or leachate collection systems
• Or even to monitor groundwater for contamination • It may be cheaper to generate waste than to avoid it
• Industries are awarded for economic, not physical, efficiency
• Once government or the market makes it efficient, businesses gain incentives to reduce their waste
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Industrial ecology seeks to make industry more sustainable• Industrial ecology
• Involves redesigning industrial systems to reduce resource inputs while maximizing physical and economic efficiency
• Based on principle that industrial systems should function like ecological systems, with little waste
• Life-cycle analysis • Examines the life cycle of a product to make the process
more ecologically efficient • Industrial ecology examines how waste products can
be used as raw materials • Eliminates harmful products and materials • Creates durable, recyclable, or reusable products
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Businesses are adopting industrial ecology
• Businesses are saving money while reducing waste • Interface, a carpet tile company, asks customers to
return used tiles for recycling and reuse • Reduced waste and adapted its boilers to use landfill gas
for energy • Cut waste generation by 80%, fossil fuel use by 45%, and
water use by 70% • Saved $30 million/year, held prices steady, and raised
profits by 49%
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An example of industrial ecology
• Swiss Zero Emissions Research and Initiatives (ZERI) helps businesses—such as breweries—create goods and services without generating waste
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Hazardous waste
• Hazardous waste • A liquid, solid, or gas that is either:
• Ignitable • Easily catches fire (natural gas, alcohol)
• Corrosive • Corrodes metals in storage tanks or equipment
• Reactive • Chemically unstable and readily reacts with other
compounds • Often explosively or by producing noxious fumes
• Toxic • Harms human health when inhaled, ingested, or touched
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Hazardous wastes are diverse
• Industry produces the largest amount of hazardous waste
• But waste generation and disposal are highly regulated • Households: the largest source of unregulated
hazardous waste • Paint, batteries, solvents, cleaners, pesticides, etc.
• Many hazardous substances become less hazardous over time
• But others may be especially persistent (e.g., radioactive waste, organic compounds, heavy metals)
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Organic compounds can be hazardous
• Synthetic organic compounds resist bacterial, fungal, and insect activity
• Plastics, tires, pesticides, solvents, wood preservatives • Keep buildings from decaying, kill pests, and keep stored
goods intact • Their resistance to decay makes them persistent
pollutants • They are toxic because they are readily absorbed through
the skin • They can act as mutagens, carcinogens, teratogens, or
endocrine disruptors
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Heavy metals can be hazardous
• Lead, chromium, mercury, arsenic, cadmium, tin, and copper
• Used widely in industry for wiring, electronics, metal plating and fabrication, pigments, and dyes
• Enter the environment when they are disposed of improperly
• Heavy metals that are fat soluble and break down slowly can bioaccumulate and biomagnify
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E-waste is growing
• Electronic waste (e-waste) • Waste involving electronic devices • Computers, printers, cell phones,
TVs, MP3 players • Americans discard 300 million
devices per year • 3/4 still work
• They are put in landfills but should be treated as hazardous waste
• Valuable trace minerals can be recovered – the 2010 Olympic medals were made from e-waste!
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Several steps precede the disposal of hazardous waste• Communities designate sites, collection days, or
facilities to gather household hazardous waste • Waste is then transported for treatment and disposal
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Several steps precede the disposal of hazardous waste (cont’d)• Under the Resource Conservation and Recovery Act
(RCRA): the EPA sets standards, but the… • States manage hazardous waste
• Large generators of hazardous waste must obtain permits
• Materials must be tracked “from cradle to grave”
• Intended to prevent illegal dumping
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Several steps precede the disposal of hazardous waste (cont’d)• Hazardous waste disposal is costly
• Often results in illegal dumping • Illegal dumping creates health risks
• Along with financial headaches for dealing with it • Industrial nations illegally dump in developing
nations • The Basel Convention, an international treaty, should
prevent dumping, but it still happens • High costs also encourage companies to invest in
reducing their hazardous waste • Incineration, bacterial and plant decomposition, etc.
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We use three disposal methods for hazardous waste
• Landfills do not lessen the hazards of the substances
• But they help keep the substance isolated from people, wildlife, and ecosystems
• Hazardous waste landfills • Their design and construction standards are stricter than
those for ordinary sanitary landfills • Must have several impervious liners and leachate
removal systems • Must be located far from aquifers
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We use three disposal methods for hazardous waste (cont’d)• Surface impoundments
• Store liquid hazardous waste • Shallow depressions are lined with plastic and clay • The liquid or slurry evaporates • The residue of solid hazardous waste is transported
elsewhere for disposal • This storage method is only temporary
• The clay layer can crack and leak waste • Rainstorms cause overflow, contaminating nearby areas
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We use three disposal methods for hazardous waste (cont’d)• Deep-well injection
• A well is drilled deep beneath the water table • Waste is injected into it • A long-term disposal method • The well is isolated from
groundwater and humans • But the wells can corrode
and leak waste
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Contaminated sites are being cleaned up
• Thousands of former military and industrial sites are contaminated with hazardous waste
• Dealing with these messes is hard, time-consuming, and expensive
• Comprehensive Environmental Response Compensation and Liability Act (CERCLA) (1980)
• Superfund is administered by the EPA • Established a federal program to clean up U.S. sites
polluted with hazardous waste
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Contaminated sites are being cleaned up (cont’d)
• The EPA must also clean up brownfields • Lands whose reuse or development is complicated by the
presence of hazardous materials • Two events spurred creation of Superfund
legislation • In Love Canal, Niagara Falls, New York, in 1978–1980,
families were evacuated after buried chemicals rose to the surface
• Times Beach, Missouri, was evacuated after contamination with dioxin from oil sprayed on roads
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The Superfund process
• Once a Superfund site is identified, EPA scientists note:
• How close the site is to human habitation • Whether wastes are currently confined or likely to spread • Whether the site threatens drinking water supplies
• Harmful sites are placed on the National Priority List • Ranked by their level of risk to human health • Cleanup occurs as funds are available
• The EPA must hold public hearings to inform area residents of its findings and to receive feedback
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Who pays for cleanup?
• CERCLA operates under the polluter-pays principle: charge polluting parties for cleanup
• However, the responsible parties often can’t be found
• A trust fund was established by a federal tax on the petroleum and chemical industries
• The fund is bankrupt, and Congress has not restored it; taxpayers now pay all costs of cleanup
• Fewer cleanups are being completed • 1326 sites remain, and only 375 have been cleaned up • Each cleanup costs $25 million and takes 15 years
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Conclusion
• We have made great strides in addressing our waste problems
• Modern methods of waste management are far safer for people and gentler on the environment
• Recycling and composting are growing rapidly • But our prodigious consumption has created more
waste than ever before • The best solution to our waste problem is to reduce
generation of waste
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