2 This lecture will help you understand: Types of wasteMajor approaches to managing wasteThe scale of the waste dilemmaLandfills and incinerationWaste reduction solutionsIndustrial waste management and ecologyHazardous waste issues
3 Central Case: Transforming New York’s Fresh Kills Landfill The largest landfill in the world, Fresh Kills was New York City’s primary waste repository.It was closed in 2001, reopening temporarily to accept debris from the collapsed World Trade Center towers.New York City now exports its waste, and plans are underway for a park at the site of the former landfill.
4 Types of wasteWaste = any unwanted item or substance resulting from a human activity or processMunicipal solid waste = from homes, institutions, small businessesIndustrial solid waste = from production of consumer goods, mining, petroleum extraction, agricultureHazardous waste = toxic, chemically reactive, flammable, or corrosiveWastewater = water used in homes, businesses, etc., and drained or flushed, plus runoff from streets
5 Why manage waste?Waste degrades water, soil, and air quality; does environmental and ecological harm.Waste does harm to human health.Waste is a symptom of inefficiency; wastes money.Waste is unpleasant aesthetically.
6 Ways to manage waste Three components of waste management: Source reduction, or reducing the amount of waste entering the waste stream, is best.Recovery (recycling and composting) is next best.Disposal is the least desired option.
7 Municipal solid wastePaper is the biggest component of municipal solid waste in the United States.
8 Municipal solid waste generation Average waste per person:1. United States 2.0 kg/day2. Canada 1.73. The Netherlands 1.4Germany and Sweden = least among developed nations: 0.9 kg/dayU.S. = “the throwaway society”
9 Municipal solid waste generation The U.S. wastes 2.7 times what it did in 1960.Per capita waste has leveled off due to recycling and source reduction.
10 Municipal solid waste generation Plastic and paper products have been growing faster than other types of waste.
11 Waste generation in developing countries Per capita waste is increasing in developing nations.People used to scavenge from this dump in the Philippines,which was closed after an avalanche of trash killed people.
12 Municipal solid waste generation Recycling has grown in recent years, stalling the growth in disposal by landfilling.
13 Landfills• In modern sanitary landfills, waste is buried or piled up so as to avoid contamination of the environment.• The Resource Conservation and Recovery Act (RCRA) specifies guidelines for how waste should be added to a landfill.
15 Reclaiming landfill sites Old landfills, capped and abandoned, can be reclaimed for other uses, including parks. Shown is Cesar Chavez Park in Berkeley, California.
16 Drawbacks of landfills Leachate will likely escape even from well-lined landfills.Dry conditions to combat leachate slow bacterial decomposition: trade-offFinding sites is difficult: NIMBY opposition
17 Landfills“Garbologist” William Rathje does archaeology in landfills to document our consumption and waste patterns.He’s found:Trash rots VERY slowly in landfills.Paper products take up 40% of landfill space.Plastic packaging is overrated as a waste problem.
18 IncinerationA controlled process of burning mixed solid waste at extremely high temperaturesReduces volume by 90%Remaining ash disposed of at landfillBetter than open-air burning, but……can create new chemical compounds and emit toxic chemicals from the stacksPopular opposition to incinerators because of pollution
19 Waste to energyMany incinerators now generate electricity from waste combustion.Waste to energy (WTE) facilities use heat from furnaces to boil water. Steam turns turbines and generators.WTE is efficient and effective, but income from power is low and expense is high, so it takes many years to recoup the investment.
21 Energy from landfills Landfills can harness energy, too. Bacterial decomposition inside landfills produces methane, the main component of natural gas.By collecting “landfill gas”:Landfills can make extra moneyFuel is made availableGreenhouse gas methane is prevented from reaching atmosphere
22 Reduction is better than disposal Source reduction, or preventing waste in the first place, is a better option than disposal.Personal/consumer behavior:Use fewer itemsBuy less-packaged and longer-lived goodsReuse itemsManufacturer behavior:Make goods with less packagingMake longer-lived goodsAdopt more-efficient production methods
23 Reuse Reusing items is a powerful way to reduce one’s waste. There are simple ways to do this:Buy used clothing, and donate used clothingBring your own cloth bags to grocery storesBring your own coffee mug to coffee shops
24 CompostingThe conversion of organic waste into mulch or humus by encouraging natural processes of decompositionReduces a home’s waste streamProduces great soil for gardeningMany communities now have municipally run composting programs.
26 RecyclingCollecting materials that can be broken down and reprocessed in order to manufacture new itemsDiverts ~55 million tons of materials away from disposal each yearItems are taken to materials recovery facilities (MRFs), where workers prepare them for reprocessing.Once readied, these materials are used in manufacturing new goods.
27 RecyclingFor recycling to work, consumers must buy goods made from recycled materials:• Many paper products• Many glass and metal products• Some plastic products• “Glassphalt” for paving• City park benches, etc.• Pages of our textbook
28 Growth of recyclingRecycling has grown rapidly and can expand further.
31 Financial incentivesOver 4,000 U.S. communities have “pay-as-you-throw” trash collection; people who waste more pay more.Eleven U.S. states have “bottle bills,” laws that mandate that consumers get money back for returning bottles and cans to where they were purchased.
32 Forces driving recycling Businesses see opportunities to save money.Entrepreneurs see opportunities for new businesses.Municipalities desire to reduce waste.People feel satisfaction in recycling responsibly.In many cases the latter two are driving recycling, and many programs today are run at an economic loss.
33 Edmonton, Alberta—a model city In just a few years, Edmonton put together an impressive recycling and composting program.Today 50% of waste is composted, and only 30% goes to a landfill. 81% of the public participates in recycling.North America’s largest composting plant, in Edmonton
34 Edmonton, Alberta—a model city Edmonton also has an MRF (recycling plant), landfill gas collection and sale, leachate treatment plant, wetland mitigation, research and public education center, and five businesses that reprocess recycled materials.Inside the composting facility, the size of 8 football fields
35 Viewpoints: Recycling Frank AckermanJane S. Shaw“…it will never be possible to recycle everything. Along with continuing efforts to expand recycling, we must ensure that there are safe, clean opportunities for disposing of the remaining, nonrecyclable, wastes.”“Recycling will continue as long as it is profitable. If it becomes more profitable, we will see more of it…We should recycle when it makes sense, but we shouldn’t be afraid to use other means as well.”
36 Industrial solid waste Each year U.S. industries generate 7.6 billion tons of total waste.97% of this is wastewaterIndustrial solid waste = roughly equivalent to amount of municipal solid wasteRegulatory schemes are different:Federal government regulates municipalState or local government regulates industrial
37 Industrial solid waste Waste is generated at several points in the life cycle of products.At each stage there are opportunities for efficiency improvements, source reduction, and recycling.
38 Waste and efficiencyThe less waste produced per item manufactured, the more efficient the process is, from a physical standpoint.But it may not mean it is economically efficient.It may be cheaper to waste materials than not to waste them.This mismatch is why there is so much industrial waste.It is because market prices do not include external costs.
39 Industrial ecologyInvolves modifying techniques of processing and manufacturing, and finding new uses for materials previously considered wasteSeeks to redesign industrial systems to maximize:Physical efficiencyANDEconomic efficiencyTries to make sure all by-products produced are used, either in the same process or a different process
40 Industrial ecology approaches Life-cycle analysis: find weak spotsFind areas where waste products from one process can be used for another processEliminate and find replacements for products that are environmentally damagingGovernment regulation of industry may be good for society, but industrial ecology is good for society AND industry.
41 Hazardous waste Waste that poses a potential danger to human health Four criteria:• Ignitability: substances catch fire• Corrosivity: substances corrode metals• Reactivity: substances are chemically unstable and react with other chemicals in dangerous ways• Toxicity: substances are known to be harmful to human health
42 Hazardous waste There are many types of hazardous waste. Two are worst because they persist for a long time without breaking down:Heavy metals(mercury, lead, chromium, arsenic, cadmium, tin, copper — from industry, mining, consumer products)Organic compounds(synthetic pesticides, petroleum products, rubber, solvents, preservatives…)
43 Household hazardous waste We all have many hazardous substances in our homes and everyday lives.Many communities organize pickups or collection centers for this waste.
44 Illegal dumpingUnscrupulous individuals or businesses sometimes illegally dump hazardous waste to avoid disposal fees.
45 Hazardous waste: Disposal methods Landfills: Special landfills with stricter regulations are used for hazardous waste.Surface impoundments: Ponds lined with plastic and clay. Liquid hazardous waste evaporates, leaving residue.Deep-well injection: Hazardous waste is pumped deep underground into porous and stable rock formations, away from aquifers.
46 Hazardous waste: Surface impoundments Really only for temporary storage; not idealWaste may overflow, blow out, vaporize, or leak
47 Hazardous waste: Deep-well injection Seems a good idea, but is not without risk:Waste can leak out into groundwater.
48 Radioactive waste A special type of hazardous waste Especially dangerousMuch produced by military and hospitals; some by research institutionsIt’s extremely hard to find a place to dump it that is not opposed by local people:Yucca Mountain, NevadaWIPP, New Mexico
49 Superfund cleanupHazardous waste sites in the U.S. are gradually being cleaned up under the Superfund program.1980: Comprehensive Environmental Response Compensation and Liability Act (CERCLA) established Superfund, administered by EPABudget from Congress plus trust fund from tax on chemicalsTries to charge responsible parties for cleanup through polluter-pays principle
50 ConclusionModern waste management methods are far safer for people and the environment than past practices.Recycling and composting have grown fast in many countries.Despite these advances, our prodigious consumption habits have created more waste than ever before.Difficult dilemmas include Superfund cleanup, safe disposal of hazardous and radioactive waste, and local opposition to disposal sites.These dilemmas indicate that the best solution to our problem is to reduce our generation of waste.
51 QUESTION: ReviewWhich is the most effective approach to reducing waste?a. Recycling glass and plastic materialsb. Reducing the amount of material that needs to be disposed ofc. Composting yard wasted. Increasing consumptione. IncinerationAnswer: B
52 QUESTION: ReviewWhich of the following is NOT a problem with sanitary landfills?a. Leachate may escape.b. Decay is very slow.c. The NIMBY syndrome inhibits where they can be located.d. Parks may be situated on old landfills.Answer: D
53 QUESTION: Review What might an industrial ecologist do? a. Study the ecology of insects on the grounds of an industrial facilityb. Look for ways to use rubber left over from manufacturing tennis balls in the manufacture of racquetball ballsc. Look for ways to save a company money manufacturing dinner plates by decreasing the physical efficiency of the processAnswer: B
54 QUESTION: Review Which substance would be considered hazardous waste? a. A powder that corrodes steel drumsb. An oil that ignites easilyc. A liquid that causes headaches and vomiting if ingestedd. A powder that turns from blue to yellow and starts smoking when in the presence of the liquid in (c)e. All of the aboveAnswer: E
55 QUESTION: Weighing the Issues Computer screens, rich in heavy metals like lead and cadmium, are an ever bigger part of the waste stream. How should they be disposed of?a. Sanitary landfillsb. Incinerationc. Hazardous waste landfillsd. Deep-well injectionAnswer: ANY
56 QUESTION: Interpreting Graphs and Data What explains the graph’s pattern?a. Population has grown more slowly than waste generation.b. Waste generation has increased exponentially and per capita generation has not.c. Recycling and source reduction have increased.d. None of the aboveAnswer: B
57 QUESTION: Interpreting Graphs and Data As a percentage of total waste, combustion…?a. Was greater than recycling in 2000b. Was greater than landfilling in 1970c. Decreased, then increased, through timed. Grew steadily from 1960 to 2000Answer: B
58 QUESTION: ViewpointsDoes recycling deserve all the acclaim it’s gotten?a. Yes; the increase to 30% recycling and beyond in such a short time is a remarkable success story.b. It deserves some acclaim, but it would be better to spend resources on encouraging reduction and reuse.c. It deserves some acclaim, but the absolute amount of trash grew faster than the amount recycled, so it’s not such a success story.Answer: ANY