Presentation is loading. Please wait.

Presentation is loading. Please wait.

22 Waste Management Part A PowerPoint® Slides prepared by

Similar presentations

Presentation on theme: "22 Waste Management Part A PowerPoint® Slides prepared by"— Presentation transcript:

1 22 Waste Management Part A PowerPoint® Slides prepared by
Jay Withgott and Kristy Manning Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings

2 This lecture will help you understand:
Types of waste Major approaches to managing waste The scale of the waste dilemma Landfills and incineration Waste reduction solutions Industrial waste management and ecology Hazardous 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 waste Waste = any unwanted item or substance resulting from a human activity or process Municipal solid waste = from homes, institutions, small businesses Industrial solid waste = from production of consumer goods, mining, petroleum extraction, agriculture Hazardous waste = toxic, chemically reactive, flammable, or corrosive Wastewater = 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 waste Paper 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/day 2. Canada 1.7 3. The Netherlands 1.4 Germany and Sweden = least among developed nations: 0.9 kg/day U.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.

14 Sanitary 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-off Finding 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 Incineration A controlled process of burning mixed solid waste at extremely high temperatures Reduces volume by 90% Remaining ash disposed of at landfill Better than open-air burning, but… …can create new chemical compounds and emit toxic chemicals from the stacks Popular opposition to incinerators because of pollution

19 Waste to energy Many 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.

20 WTE incineration

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 money Fuel is made available Greenhouse 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 items Buy less-packaged and longer-lived goods Reuse items Manufacturer behavior: Make goods with less packaging Make longer-lived goods Adopt 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 clothing Bring your own cloth bags to grocery stores Bring your own coffee mug to coffee shops

24 Composting The conversion of organic waste into mulch or humus by encouraging natural processes of decomposition Reduces a home’s waste stream Produces great soil for gardening Many communities now have municipally run composting programs.

25 Recycling Consists of three steps:

26 Recycling Collecting materials that can be broken down and reprocessed in order to manufacture new items Diverts ~55 million tons of materials away from disposal each year Items are taken to materials recovery facilities (MRFs), where workers prepare them for reprocessing. Once readied, these materials are used in manufacturing new goods.

27 Recycling For 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 recycling Recycling has grown rapidly and can expand further.

29 Recycling rates

30 Recycling rates by state

31 Financial incentives Over 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 Ackerman Jane 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 wastewater Industrial solid waste = roughly equivalent to amount of municipal solid waste Regulatory schemes are different: Federal government regulates municipal State 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 efficiency The 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 ecology Involves modifying techniques of processing and manufacturing, and finding new uses for materials previously considered waste Seeks to redesign industrial systems to maximize: Physical efficiency AND Economic efficiency Tries 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 spots Find areas where waste products from one process can be used for another process Eliminate and find replacements for products that are environmentally damaging Government 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 dumping Unscrupulous 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 ideal Waste 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 dangerous Much produced by military and hospitals; some by research institutions It’s extremely hard to find a place to dump it that is not opposed by local people: Yucca Mountain, Nevada WIPP, New Mexico

49 Superfund cleanup Hazardous 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 EPA Budget from Congress plus trust fund from tax on chemicals Tries to charge responsible parties for cleanup through polluter-pays principle

50 Conclusion Modern 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: Review Which is the most effective approach to reducing waste? a. Recycling glass and plastic materials b. Reducing the amount of material that needs to be disposed of c. Composting yard waste d. Increasing consumption e. Incineration Answer: B

52 QUESTION: Review Which 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 facility b. Look for ways to use rubber left over from manufacturing tennis balls in the manufacture of racquetball balls c. Look for ways to save a company money manufacturing dinner plates by decreasing the physical efficiency of the process Answer: B

54 QUESTION: Review Which substance would be considered hazardous waste?
a. A powder that corrodes steel drums b. An oil that ignites easily c. A liquid that causes headaches and vomiting if ingested d. A powder that turns from blue to yellow and starts smoking when in the presence of the liquid in (c) e. All of the above Answer: 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 landfills b. Incineration c. Hazardous waste landfills d. Deep-well injection Answer: 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 above Answer: B

57 QUESTION: Interpreting Graphs and Data
As a percentage of total waste, combustion…? a. Was greater than recycling in 2000 b. Was greater than landfilling in 1970 c. Decreased, then increased, through time d. Grew steadily from 1960 to 2000 Answer: B

58 QUESTION: Viewpoints Does 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

Download ppt "22 Waste Management Part A PowerPoint® Slides prepared by"

Similar presentations

Ads by Google