1. Waste and Recycling Notes Waste Disposal

2. Electronic 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.
Figure 22-4

7. Chapter Overview Questions
What is solid waste and how much do we produce?
How can we produce less solid waste?
What are the advantages and disadvantages of reusing recycled materials?
What are the advantages and disadvantages of burning or burying solid waste?
What is hazardous waste and how can we deal with it?

8. Chapter Overview Questions (cont’d)
What can we do to reduce exposure to lead and mercury?
How can we make the transition to a more sustainable low-waste society?

9. Core Case Study: Love Canal — There Is No “Away”
Between , 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.

10. Core Case Study: Love Canal — There Is No “Away”
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.

11. Core Case Study: Love Canal — There Is No “Away”
President Jimmy Carter declared Love Canal a federal disaster area.
The area was abandoned in 1980 (left).
Figure 22-1

12. Core Case Study: Love Canal — There Is No “Away”
It still is a controversy as to how much the chemicals at Love Canal injured or caused disease to the residents.
Love Canal sparked creation of the Superfund law, which forced polluters to pay for cleaning up abandoned toxic waste dumps.

13. Early Concepts of Waste Disposal
Start of Industrial Revolution, the volume of waste produced in the US was relatively small.
Managed through the concept of “dilute and disperse.”
Factories located near water.
Easy transport of materials by boat
Sufficient water for processing and cooling
Easy disposal of waste into the river
Few factories and a sparse population
Method was sufficient to remove the waste from the immediate environment.

14. Early Concepts of Waste Disposal
As industrial and urban areas expanded, the concept became “concentrate and contain”
Containment not always achieved.
Containers leak or break and allow waste to escape.
People are facing a serious solid-waste disposal problem.
We are producing a great deal of waste and the acceptable space for permanent disposal is limited.
Difficult to site new landfills (NIMBY).

15. Modern Trends
Environmentally correct concept is to consider wastes as resources out of place.
Waste would be a resource to be used again.
Referred to as the “zero waste” movement.
Industrial ecology
Study of relationships among industrial systems and their links to natural systems.
Waste from one part of the system would be a resource for another part.

16. Modern Trends Countries have moved to cut waste by imposing taxes.
Taxation of waste in all its various forms, from emissions from smokestacks to solids delivered to landfills.
As taxes increase people produce less waste.
Landfills produce methane gas which can be burned as fuel.

17. Integrated Waste Management
A set of management alternatives that includes:
Reuse
Source reduction
Recycling
Composting
Landfill
Incineration

18. Reduce, Reuse, Recycle
Ultimate objective of the three R’s is to reduce.
Study of the waste stream in areas that utilize IWM technology suggests that the amount of refuse disposed of in landfills or incinerated can be reduced by at least 50%
Reduction facilitated by
Better design of packaging to reduce waste, an element of source reduction (10% reduction).
Large-scale composting programs (10% reduction).
Establishment of recycling programs (30% reduction).

19. Reduce, Reuse, Recycle
Recycling is a major player in the reduction of urban waste stream.
Estimated that as much as 80-90% of the US waste stream might be recovered through intense recycling.
Partial recycling can provide a significant reduction ~50%.
Simplified by single stream recycling.

21. Public Support for Recycling
Encouraging signs
An increase in the willingness of industry and business to support recycling on a variety of scales.
People are now more likely to purchase products that can be recycled or that come in containers that are more easily recycled or composted.

22. How does the public feel about recycling?

23. Markets for Recycled Products
In communities where recycling has been successfully implemented, it has resulted in glutted markets for the recycled products.
If recycling is to be successful,
markets and processing facilities will also have to be developed to ensure that recycling is a sound financial venture.

24. Recycling of Human Waste
The use of human waste or “night soil” on croplands is an ancient practice.
Early uses of human waste for agriculture occasionally spread infectious diseases.
One of the major problems of recycling human waste today is that thousands of chemicals and metals flow through our waste stream.
Because many toxic materials are likely to be present with the waste, we must be very skeptical of utilizing sewage sludge for land application.

25. Materials Management
Futuristic waste management has the goal of zero production of waste.
Consistent with the ideals of industrial ecology.
Goal will require more sustainable use of materials combined with resource conservation in what is being termed materials management.

26. Materials Management The goal could be pursued in the following ways:
Eliminate subsidies for extraction of virgin materials.
Establish “green building” incentives that encourage the use of recycled-content materials and products in new construction.
Assess financial penalties for production that uses negative materials management practices.

27. Materials Management
Provide financial incentives for industrial practices and products that benefit the environment by enhancing sustainability.
Increase the number of new jobs in the technology of reuse and recycling of resources.

28. Composition of Solid Waste
Paper is by far the most abundant content.
Excavations into modern landfills using archeological tools have cleared up some misconceptions concerning other items.
Fast-food packaging accounts for about 0.25% of the average landfill
Disposable diapers, approximately 0.8%
Polystyrene products, about 0.9%

29. Solid-Waste Management
Continues to be a problem in many parts of the world.
Many practices inadequate.
Open dumps, illegal roadside dumping
Social problem as much as a physical one, because many people are simply disposing of their waste as inexpensively and as quickly as possible.

31. On-Site Disposal
A common on-site disposal method in urban areas is the mechanical grinding of kitchen food waste.
Garbage-disposal devices are installed at the kitchen sink, and the garbage is ground and flushed into the sewer system.

32. Composting
Biochemical process in which organic materials decompose to a rich, soil-like material.
The process involves rapid partial decomposition of moist solid organic waste by aerobic organisms.
As a waste management option, large-scale composting is generally carried out in the controlled environment of mechanical digesters.

33. Incineration
Combustible waste is burned at temperatures high enough (900°–1,000°C, or 1,650°–1,830°F) to consume all combustible material.
Leaving only ash and non-combustibles to dispose of in a landfill.
Process of incineration can be used to supplement other fuels and generate electrical power.
In modern incineration facilities, smokestacks are fitted with special devices to trap pollutants.

34. Open Dumps
In the past, solid waste was often disposed of in open dumps, where the refuse was piled up without being covered or otherwise protected.
Located wherever land is available, without regard to safety, health hazards, or aesthetic degradation.
Common sites
Abandoned mines and quarries, natural low areas, such as swamps or floodplains; and hillside areas above or below towns.

36. Sanitary Landfills
Designed to concentrate and contain refuse w/o creating a nuisance or hazard to public health or safety.
Confined to the smallest practical area
Reduced to the smallest practical volume
Covered with a layer of compacted soil at the end of each day of operation.

37. Leachate
The most significant hazard from a sanitary landfill is pollution of groundwater or surface water.
If waste comes into contact with water, leachate is produced.
noxious, mineralized liquid capable of transporting bacterial pollutants

38. WASTING RESOURCES
Solid waste: any unwanted or discarded material we produce that is not a liquid or gas.
Municipal solid waste (MSW): produce directly from homes.
Industrial solid waste: produced indirectly by industries that supply people with goods and services.
Hazardous (toxic) waste: threatens human health or the environment because it is toxic, chemically active, corrosive or flammable.

39. WASTING RESOURCES
Solid wastes polluting a river in Jakarta, Indonesia. The man in the boat is looking for items to salvage or sell.
Figure 22-3

40. WASTING RESOURCES
The United States produces about a third of the world’s solid waste and buries more than half of it in landfills.
About 98.5% is industrial solid waste.
The remaining 1.5% is MSW.
About 55% of U.S. MSW is dumped into landfills, 30% is recycled or composted, and 15% is burned in incinerators.

41. Landfills
Definition
Solid waste is placed in a hole, compacted, and covered with soil.
Reduces the number of rats associated with solid waste, lessens the danger of fire, and decreases the odor.

42. Current Criteria Landfills cannot pollute surface or groundwater.
Compacted clay and plastic sheets are at the bottom (prevents liquid waste from seeping into groundwater)
A double liner system must be present (plastic, clay, plastic, clay), and a system to collect leachate (liquid that seeps through the solid waste)

43. Oil
Not allowed
Must go to an automotive or environmental company for recycling.

44. Tires
Are usually allowed if they are quartered or shredded.

45. Antifreeze Not allowed.
Must be sent to an automotive or environmental company for recycling.

46. Air Conditioner Coolants
Not allowed
Must be sent to an automotive or environmental company for recycling.

47. Lead Acid (Car Batteries)
Not allowed
Must be sent to an automotive or an environmental company for recycling.

48. Compost
Definition
A sweet-smelling, dark-brown, humus-like material that is rich in organic material and soil nutrients.

49. Benefits Aerates the soil.
Improves soil’s ability to retain water and nutrients.
Helps prevent erosion.
Prevents nutrients from being dumped in landfills.

50. Recycling
Definition
Conservation of resources by converting them into new product.

51. Organic Comprise over 1/2 of the solid waste
Includes yard debris, wood materials, bio-solids, food, manure and agricultural residues, land clearing debris, used paper, and mixed municipal organic waste.
Organic materials have been dumped in landfills or burned. Why not use them!

52. General Purpose
Recycling saves land, reduces the amount of solid waste, energy consumption and pollution.
Ex. recycling one aluminum can saves the energy of about 6 oz. of gasoline.

53. Examples
Gold, lead, nickel, steel, copper, silver, zinc, and aluminum are recyclable.

55. Problems Recycling does have environmental costs.
It uses energy and generates pollution.
Ex. the de-inking process in paper recycling requires energy, and produces a toxic sludge that contains heavy metals.

56. Benefits Conserves our natural resources
Has a positive effect on the economy by generating jobs and revenues.
For example, the Sunday edition of the New York Times consumes 62,000 trees.
Currently, only about 20% of all paper in North America is recycled.

57. Specific Recycled Items

58. Glass U.S. recycles about 36% of its glass containers.
It costs less to recycle glass than to make new glass.
Mixed color glass “cullet” is used for glassphalt, a glass/asphalt mixture.

59. Aluminum This is the most recycled material in the U.S. because of $.
Making a new can from an old one requires a fraction of the energy than to make a new can from raw materials.
Approximately 2/3 of cans are recycled each year, saving 19 million barrels of oil annually.

60. Paper U.S. currently recycles 40% of its paper and paperboard.
Denmark, recycles about 97% of its paper.
Many U.S. mills are not able to process waste paper.
Many countries like Mexico, import a large amount of wastepaper from the U.S.
We export about 19% of our recycled paper.

61. Recyclable Plastics

62. #1 - PET (Polyethylene terephthalate)
PET is used to make soft drink bottles, peanut butter jars, etc.
PET can be recycled into fiberfill for sleeping bags, carpet fibers, rope, and pillows.

63. #2 - HDPE (High-density polyethylene)
HDPE is found in milk jugs, butter tubs, detergent bottles, and motor oil bottles.
HDPE can be recycled into flowerpots, trashcans, traffic barrier cones, and detergent bottles.

64. #3 - PVC (Polyvinyl chloride)
PVC is used in shampoo and cooking oil bottles & fast-food service items.

65. #4 - LDPE (Low-density polyethylene)
LDPE is found in grocery bags, bread bags, shrink-wrap, and margarine tub tops.
LDPE can be recycled into new grocery bags.

66. #5 - PP (Polypropylene)
PP is used in yogurt containers, straws, pancake syrup bottles, and bottle caps.
PP can be recycled into plastic lumber, car battery cases, and manhole steps.

67. #6 - PS (Polystyrene)
PS is found in disposable hot cups, packaging materials (peanuts), & meat trays.
PS can be recycled into plastic lumber, cassette tape boxes, and flowerpots.

68. #7 - Other
A mixture of various plastics, like squeeze ketchup bottles & “microwaveable” dishes.

69. Nuclear Waste The safe disposal of radioactive wastes is the problem.
Radioactive wastes must be stored in an isolated area where they can’t contaminate the environment.
It must have geological stability and little or no water flowing nearby.

70. Texas Production of Waste
The TNRCC oversees the municipal waste in Texas.
In 1998, the solid waste disposal rate for Texans was 6.5 pounds per person per day.
This is based on every item that goes into a landfill.
The TNRCC estimates that 12,740,234 tons were diverted for recycling in 1998.
Texans disposal rate is comparable to the US disposal rate.

71. Packaging
Many packaging items are put into landfills, including boxes, packing peanuts, Styrofoam, shrink wrap, etc.
Try to buy things that are not as highly packaged.
Many companies use peanuts that are made from cellulose that can be washed down the drain and not put into landfills.
Reuse containers and buy smart!

72. Integrated Waste Management
Definition
The most effective way to deal with solid and hazardous waste and hazardous waste.
This includes the three R’s: reduce, reuse, and recycle.

73. INTEGRATED WASTE MANAGEMENT
We can manage the solid wastes we produce and reduce or prevent their production.

74. First Priority Second Priority Last Priority Primary Pollution
and Waste Prevention
Secondary Pollution
and Waste Prevention
Waste Management
• Treat waste to reduce
toxicity
• Change industrial
process to eliminate
use of harmful
chemicals
• Reuse products
• Repair products
• Incinerate waste
• Recycle
• Bury waste in
landfills
• Purchase different
products
• Compost
• Release waste into
environment for
dispersal or dilution
• Buy reusable
recyclable products
• Use less of a harmful
product
• Reduce packaging
and materials in
products
Figure 22.5
Integrated waste management: priorities suggested by prominent scientists for dealing with solid waste. To date, these waste-reduction priorities have not been followed in the United States and in most other countries. Instead, most efforts are devoted to waste management (bury it or burn it). QUESTION: Why do most countries not follow these priorities based on sound science? (Data from U.S. Environmental Protection Agency and U.S. National Academy of Sciences)
• Make products that
last longer and are
recyclable, reusable,
or easy to repair
Fig. 22-5, p. 523

75. Solutions: Reducing Solid Waste
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.

76. Reuse, Repurpose, and Recycle.
What Can You Do?
Solid Waste
• Follow the five Rs of resource use: Refuse, Reduce,
Reuse, Repurpose, and Recycle.
• Ask yourself whether you really need a particular item.
• Rent, borrow, or barter goods and services when you can.
• Buy things that are reusable, recyclable, or compostable, and be sure to reuse, recycle, and compost them.
• Do not use throwaway paper and plastic plates,
cups and eating utensils, and other disposable items when reusable or refillable versions are available.
Figure 22.6
Individuals matter: ways to save resources and reduce your output of solid waste and pollution. QUESTIONS: Which three of these actions do you think are the most important? Which ones do you do?
• Refill and reuse a bottled water container with tap water.
• Use in place of conventional paper mail.
• Read newspapers and magazines online.
• Buy products in concentrated form whenever possible.
Fig. 22-6, p. 524

77. REUSE
Reusing products is an important way to reduce resource use, waste, and pollution in developed countries.
Reusing can be hazardous in developing countries for poor who scavenge in open dumps.
They can be exposed to toxins or infectious diseases.

78. RECYCLING
Primary (closed loop) recycling: materials are turned into new products of the same type.
Secondary recycling: materials are converted into different products.
Used tires shredded and converted into rubberized road surface.
Newspapers transformed into cellulose insulation.

79. RECYCLING
Composting biodegradable organic waste mimics nature by recycling plant nutrients to the soil.
Recycling paper has a number of environmental (reduction in pollution and deforestation, less energy expenditure) and economic benefits and is easy to do.

80. RECYCLING
Recycling many plastics is chemically and economically difficult.
Many plastics are hard to isolate from other wastes.
Recovering individual plastic resins does not yield much material.
The cost of virgin plastic resins in low than recycled resins due to low fossil fuel costs.
There are new technologies that are making plastics biodegradable.

81. BURNING AND BURYING SOLID WASTE
Globally, MSW is burned in over 1,000 large waste-to-energy incinerators, which boil water to make steam for heating water, or space, or for production of electricity.
Japan and a few European countries incinerate most of their MSW.

82. Waste-to-Energy Incineration
1) the volume of waste is reduced by up to 90% and 2) the heat produced, produces steam, which can warm buildings or generate electricity.
In 1999, the U.S. had 110 w-to-e incinerators, which burned 16% of the nation’s solid waste & produces less CO2 emissions than power plants that run on fossil fuels. Giant piles of tires are also being burned to supply electricity.

83. Burning Solid Waste
Waste-to-energy incinerator with pollution controls that burns mixed solid waste.
Figure 22-10

84. Burying Solid Waste
Most of the world’s MSW is buried in landfills that eventually are expected to leak toxic liquids into the soil and underlying aquifers.
Open dumps: are fields or holes in the ground where garbage is deposited and sometimes covered with soil. Mostly used in developing countries.
Sanitary landfills: solid wastes are spread out in thin layers, compacted and covered daily with a fresh layer of clay or plastic foam.

85. Pipes collect explosive methane as used as fuel
When landfill is full,
layers of soil and clay
seal in trash
Topsoil
Electricity
generator
building
Sand
Clay
Methane storage
and compressor
building
Leachate
treatment system
Garbage
Probes to
detect
methane
leaks
Pipes collect explosive methane as used as fuel
to generate electricity
Methane gas
recovery well
Leachate
storage
tank
Compacted
solid waste
Figure 22.12
Solutions: state-of-the-art sanitary landfill, which is designed to eliminate or minimize environmental problems that plague older landfills. Even these landfills are expected to leak eventually, passing both the effects of contamination and cleanup costs on to future generations. Since 1997, only modern sanitary landfills are allowed in the United States. As a result, many older and small landfills have been closed and replaced with larger local and regional modern landfills.
Garbage
Groundwater
monitoring
well
Leachate
pipes
Leachate pumped
up to storage tank
for safe disposal
Sand
Synthetic
liner
Leachate
monitoring
well
Clay and plastic lining
to prevent leaks; pipes
collect leachate from
bottom of landfill
Sand
Clay
Groundwater
Subsoil
Fig , p. 532

86. Case Study: What Should We Do with Used Tires?
We face a dilemma in deciding what to so with hundreds of millions of discarded tires.
Figure 22-14

87. HAZARDOUS WASTE
Hazardous waste: is any discarded solid or liquid material that is toxic, ignitable, corrosive, or reactive enough to explode or release toxic fumes.
The two largest classes of hazardous wastes are organic compounds (e.g. pesticides, PCBs, dioxins) and toxic heavy metals (e.g. lead, mercury, arsenic).

88. Hazardous Waste Regulations in the United States
Two major federal laws regulate the management and disposal of hazardous waste in the U.S.:
Resource Conservation and Recovery Act (RCRA)
Cradle-to-the-grave system to keep track waste.
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)
Commonly known as Superfund program.
You must know these two laws!

89. Hazardous Waste Regulations in the United States
The Superfund law was designed to have polluters pay for cleaning up abandoned hazardous waste sites.
Only 70% of the cleanup costs have come from the polluters, the rest comes from a trust fund financed until 1995 by taxes on chemical raw materials and oil.

90. Conversion to Less Hazardous Substances
Physical Methods: using charcoal or resins to separate out harmful chemicals.
Chemical Methods: using chemical reactions that can convert hazardous chemicals to less harmful or harmless chemicals.

91. Conversion to Less Hazardous Substances
Biological Methods:
Bioremediation: bacteria or enzymes help destroy toxic and hazardous waste or convert them to more benign substances.
Phytoremediation: involves using natural or genetically engineered plants to absorb, filter and remove contaminants from polluted soil and water.

92. Radioactive contaminants Organic contaminants Inorganic
metal contaminants
Poplar tree
Brake fern
Sunflower
Willow tree
Indian mustard
Landfill
Polluted
groundwater in
Oil
spill
Figure 22.17
Solutions: phytoremediation. Various types of plants can be used as pollution sponges to clean up soil and water and radioactive substances (left), organic compounds (center), and toxic metals (right). (Data from American Society of Plant Physiologists, U.S. Environmental Protection Agency, and Edenspace)
Polluted
leachate
Decontaminated
water out
Soil
Soil
Groundwater
Groundwater
Phytodegradation
Plants such as poplars
can absorb toxic organic
chemicals and break them down into less harmful compounds which they store or
release slowly into the air.
Rhizofiltration
Roots of plants such as
sunflowers with dangling
roots on ponds or in green-
houses can absorb pollutants
such as radioactive strontium-90 and cesium-137 and various
organic chemicals.
Phytoextraction
Roots of plants such as Indian
mustard and brake ferns can
absorb toxic metals such as
lead, arsenic, and others and
store them in their leaves.
Plants can then be recycled
or harvested and incinerated.
Phytostabilization
Plants such as willow trees and poplars can absorb chemicals and keep them from reaching groundwater or nearby surface water.

93. Phytodegradation Rhizofiltration Phytostabilization Phytoextraction
Radioactive
contaminants
Organic
contaminants
Inorganic
metal contaminants
Poplar tree
Brake fern
Sunflower
Willow tree
Indian mustard
Landfill
Oil
spill
Polluted
groundwater in
Figure 22.17
Solutions: phytoremediation. Various types of plants can be used as pollution sponges to clean up soil and water and radioactive substances (left), organic compounds (center), and toxic metals (right). (Data from American Society of Plant Physiologists, U.S. Environmental Protection Agency, and Edenspace)
Polluted
leachate
Decontaminated
water out
Soil
Soil
Groundwater
Groundwater
Phytodegradation
Rhizofiltration
Phytostabilization
Phytoextraction

94. Radioactive
contaminants
Organic
contaminants
Inorganic
metal contaminants
Poplar tree
Brake fern
Sunflower
Willow tree
Indian mustard
Landfill
Polluted
groundwater in
Oil
spill
Figure 22.17
Solutions: phytoremediation. Various types of plants can be used as pollution sponges to clean up soil and water and radioactive substances (left), organic compounds (center), and toxic metals (right). (Data from American Society of Plant Physiologists, U.S. Environmental Protection Agency, and Edenspace)
Polluted
leachate
Decontaminated
water out
Soil
Soil
Groundwater
Groundwater
Rhizofiltration
Roots of plants such as sunflowers with dangling roots on ponds or in green-houses can absorb pollutants such as radioactive strontium-90 and cesium-137 and various organic chemicals.

95. Radioactive
contaminants
Organic
contaminants
Inorganic
metal contaminants
Poplar tree
Brake fern
Sunflower
Willow tree
Indian mustard
Landfill
Polluted
groundwater in
Oil
spill
Figure 22.17
Solutions: phytoremediation. Various types of plants can be used as pollution sponges to clean up soil and water and radioactive substances (left), organic compounds (center), and toxic metals (right). (Data from American Society of Plant Physiologists, U.S. Environmental Protection Agency, and Edenspace)
Polluted
leachate
Decontaminated
water out
Soil
Soil
Groundwater
Groundwater
Phytostabilization
Plants such as willow trees and poplars can absorb chemicals and keep them from reaching groundwater or nearby surface water.

96. Radioactive
contaminants
Organic
contaminants
Inorganic
metal contaminants
Poplar tree
Brake fern
Sunflower
Willow tree
Indian mustard
Landfill
Polluted
groundwater in
Oil
spill
Figure 22.17
Solutions: phytoremediation. Various types of plants can be used as pollution sponges to clean up soil and water and radioactive substances (left), organic compounds (center), and toxic metals (right). (Data from American Society of Plant Physiologists, U.S. Environmental Protection Agency, and Edenspace)
Polluted
leachate
Decontaminated
water out
Soil
Soil
Groundwater
Groundwater
Phytodegradation
Plants such as poplars can absorb toxic organic chemicals and break them down into less harmful compounds which they store or release slowly into the air.

97. Radioactive
contaminants
Organic
contaminants
Inorganic
metal contaminants
Poplar tree
Brake fern
Sunflower
Willow tree
Indian mustard
Landfill
Polluted
groundwater in
Oil
spill
Figure 22.17
Solutions: phytoremediation. Various types of plants can be used as pollution sponges to clean up soil and water and radioactive substances (left), organic compounds (center), and toxic metals (right). (Data from American Society of Plant Physiologists, U.S. Environmental Protection Agency, and Edenspace)
Polluted
leachate
Decontaminated
water out
Soil
Soil
Groundwater
Groundwater
Phytoextraction
Roots of plants such as Indian mustard and brake ferns can absorb toxic metals such as lead, arsenic, and others and store them in their leaves. Plants can then be recycled or harvested and incinerated.

98. Conversion to Less Hazardous Substances
Incineration: heating many types of hazardous waste to high temperatures – up to 2000 °C – in an incinerator can break them down and convert them to less harmful or harmless chemicals.

99. Conversion to Less Hazardous Substances
Plasma Torch: passing electrical current through gas to generate an electric arc and very high temperatures can create plasma.
The plasma process can be carried out in a torch which can decompose liquid or solid hazardous organic material.

100. Long-Term Storage of Hazardous Waste
Hazardous waste can be disposed of on or underneath the earth’s surface, but without proper design and care this can pollute the air and water.
Deep-well disposal: liquid hazardous wastes are pumped under pressure into dry porous rock far beneath aquifers.
Surface impoundments: excavated depressions such as ponds, pits, or lagoons into which liners are placed and liquid hazardous wastes are stored.

101. Long-Term Storage of Hazardous Waste
Long-Term Retrievable Storage: Some highly toxic materials cannot be detoxified or destroyed. Metal drums are used to stored them in areas that can be inspected and retrieved.
Secure Landfills: Sometimes hazardous waste are put into drums and buried in carefully designed and monitored sites.

102. Secure Hazardous Waste Landfill
In the U.S. there are only 23 commercial hazardous waste landfills.
Figure 22-22

103. ACHIEVING A LOW-WASTE SOCIETY
In the U.S., citizens have kept large numbers of incinerators, landfills, and hazardous waste treatment plants from being built in their local areas.
Environmental justice means that everyone is entitled to protection from environmental hazards without discrimination.

104. Global Outlook: International Action to Reduce Hazardous Waste
An international treaty calls for phasing out the use of harmful persistent organic pollutants (POPs).
POPs are insoluble in water and soluble in fat.
Nearly every person on earth has detectable levels of POPs in their blood.
The U.S has not ratified this treaty.

105. Making the Transition to a Low-Waste Society: A New Vision
Everything is connected.
There is no “away” for the wastes we produce.
Dilution is not always the solution to pollution.
The best and cheapest way to deal with wastes are reduction and pollution prevention.