1. Section 5 Section 6 Section 7 Section 8
Ch 22 Waste Management
Section 5 Section 6
Section 7 Section 8

2. 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.

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

4. Trade-Offs Incineration Advantages Disadvantages Expensive to build
Reduces trash volume
Expensive to build
Costs more than
short-distance
hauling to
landfills
Less need
for landfills
Low water pollution
Difficult to site because of citizen opposition
Concentrates hazardous substances
into ash for
burial or use
as landfill
cover
Some air pollution
Older or poorly managed facilities can release large amounts of air pollution
Figure 22.11
Trade-offs: advantages and disadvantages of waste-to-energy incineration of solid waste. These trade-offs also apply to the incineration of hazardous waste. QUESTION: Which single advantage and which single disadvantage do you think are the most important?
Output approach that encourages waste production
Sale of energy reduces cost
Modern controls reduce air pollution
Can compete with recycling for burnable materials such as newspaper
Some facilities recover and sell metals
Fig , p. 531

5. 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.

6. 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
Sand
Clay and plastic lining
to prevent leaks; pipes
collect leachate from
bottom of landfill
Groundwater
Clay
Subsoil
Fig , p. 532

7. Trade-Offs Sanitary Landfills Advantages Disadvantages
Noise and traffic
No open burning
Dust
Little odor
Air pollution from toxic gases and volatile organic
compounds
Low groundwater
pollution if sited properly
Releases greenhouse gases (methane and CO2)
unless they are collected
Can be built quickly
Low operating costs
Groundwater contamination
Figure 22.13
Trade-offs: advantages and disadvantages of using sanitary landfills to dispose of solid waste. QUESTION: Which single advantage and which single disadvantage do you think are the most important?
Can handle large amounts of waste
Slow decomposition
of wastes
Filled land can be used for other purposes
Discourages recycling, reuse, and waste reduction
No shortage of landfill space in many areas
Eventually leaks and can contaminate groundwater
Fig , p. 533

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

9. 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).

10. What Harmful Chemicals Are in Your Home?
Cleaning
Gardening
• Disinfectants
• Pesticides
• Drain, toilet, and
window cleaners
• Weed killers
• Ant and rodent killers
• Spot removers
• Septic tank cleaners
• Flea powders
Paint
• Latex and oil-based paints
• Paint thinners, solvents,
and strippers
Automotive
• Stains, varnishes,
and lacquers
Figure 22.15
Science: harmful chemicals found in many U.S. homes. The U.S. Congress has exempted disposal of these materials from government regulation. QUESTION: Which of these chemicals are in your home?
• Gasoline
• Wood preservatives
• Used motor oil
• Antifreeze
• Artist paints and inks
• Battery acid
General
• Solvents
• Dry-cell batteries
(mercury and cadmium)
• Brake and
transmission fluid
• Glues and cements
• Rust inhibitor and
rust remover
Fig , p. 534

11. 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.

12. 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.

13. How Would You Vote?
To conduct an instant in-class survey using a classroom response system, access “JoinIn Clicker Content” from the PowerLecture main menu for Living in the Environment.
Should the U.S. Congress reinstate the polluter-pays principle by using taxes from chemical, oil, mining, and smelting companies to reestablish a fund for cleaning up existing and new Superfund sites?
a. No. All taxpayers, not certain industries, should pay for cleaning up sites polluted in the past.
b. Yes. Funding for Superfund is needed and waste-generating industries rather than ordinary citizens should fund it.

14. DEALING WITH HAZARDOUS WASTE
We can produce less hazardous waste and recycle, reuse, detoxify, burn, and bury what we continue to produce.
Figure 22-16

15. Convert to Less Hazardous or Nonhazardous Substances
Produce Less Waste
Manipulate
processes
to eliminate
or reduce
production
Recycle
and
reuse
Convert to Less Hazardous or Nonhazardous Substances
Chemical,
physical, and
biological
treatment
Ocean and
atmospheric
assimilation
Land
treatment
Thermal
treatment
Incineration
Figure 22.16
Integrated hazardous waste management: priorities suggested by prominent scientists for dealing with hazardous waste. To date, these priorities have not been followed in the United States and in most other countries. (Data from U.S. National Academy of Sciences)
Put in Perpetual Storage
Arid region
unsaturated
zone
Waste
piles
Surface
impoundments
Salt
formations
Underground
injection
Landfill
Fig , p. 536

16. 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.

17. 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.

18. 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.
Phytostabilization
Plants such as willow trees and poplars can absorb chemicals and keep them from reaching groundwater or nearby surface water.
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.
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.

19. Can reduce material dumped into landfills
Trade-Offs
Phytoremediation
Advantages
Disadvantages
Easy to establish
Slow (can
take several
growing
seasons)
Inexpensive
Effective only
at depth plant
roots can
reach
Can reduce material dumped into landfills
Some toxic organic chemicals may evaporate from plant leaves
Figure 22.18
Trade-offs: advantages and disadvantages of using phytoremediation to remove or detoxify hazardous waste. QUESTION: Which single advantage and which single disadvantage do you think are the most important?
Produces little air pollution compared to incineration
Some plants
can become
toxic to
animals
Low energy use
Fig , p. 538

20. 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.

21. 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.

22. Mobile. Easy to move to different sites
Trade-Offs
Plasma Arc
Advantages
Disadvantages
Small
High cost
Produces CO2 and CO
Mobile. Easy to move to different sites
Can release particulates and chlorine gas
Figure 22.19
Trade-offs: advantages and disadvantages of using a plasma arc torch to detoxify hazardous wastes. QUESTION: Which single advantage and which single disadvantage do you think are the most important?
Can vaporize and release toxic metals and radioactive elements
Produces no
toxic ash
Fig , p. 538

23. 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.

24. Deep Underground Wells
Trade-Offs
Deep Underground Wells
Advantages
Disadvantages
Safe method if
sites are chosen
carefully
Leaks or spills at
surface
Leaks from
corrosion of well
casing
Wastes can be
retrieved if
problems
develop
Existing fractures
or earthquakes
can allow wastes
to escape into
groundwater
Figure 22.20
Trade-offs: advantages and disadvantages of injecting liquid hazardous wastes into deep underground wells. QUESTION: Which single advantage and which single disadvantage do you think are the most important?
Easy to do
Encourages
waste production
Low cost
Fig , p. 539

25. Low construction costs
Trade-Offs
Surface Impoundments
Advantages
Disadvantages
Groundwater
contamination
from leaking liners
(or no lining)
Low construction costs
Low operating costs
Air pollution from
volatile organic
compounds
Can be built quickly
Overflow from
flooding
Figure 22.21
Trade-offs: advantages and disadvantages of storing liquid hazardous wastes in surface impoundments. QUESTION: Which single advantage and which single disadvantage do you think are the most important?
Wastes can be retrieved if necessary
Disruption and
leakage from
earthquakes
Can store wastes indefinitely with secure double liners
Promotes waste
production
Fig , p. 539

26. 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.

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

28. Bulk waste Gas vent Topsoil Plastic cover Earth Impervious clay cap
Sand
Clay
cap
Impervious
clay
Water
table
Figure 22.22
Solutions: secure hazardous waste landfill.
Earth
Leak
detection
system
Groundwater
Plastic
double
liner
Double leachate
collection system
Reactive
wastes
in drums
Groundwater
monitoring
well
Fig , p. 540

29. • Use pesticides in the smallest amount possible.
What Can You Do?
Hazardous Waste
• Use pesticides in the smallest amount possible.
• Use less harmful substances instead of commercial chemicals for most household cleaners. For example use liquid ammonia to clean appliances and windows; vinegar to polish metals, clean surfaces, and remove stains and mildew; baking soda to clean household utensils, deodorize, and remove stains; borax to
remove stains and mildew.
Figure 22.23
Individuals matter: ways to reduce your input of hazardous waste into the environment. QUESTION: Which two things in this list do you do or plan to do?
• Do not dispose of pesticides, paints, solvents, oil, antifreeze, or other products containing hazardous chemicals by flushing them down the toilet, pouring them down the drain, burying them, throwing them into the garbage, or dumping them down storm drains.
Fig , p. 540

30. Case Study: Lead
Lead is especially harmful to children and is still used in leaded gasoline and household paints in about 100 countries.
Figure 22-24

31. Solutions Lead Poisoning Prevention Control
Phase out leaded gasoline worldwide
Sharply reduce lead emissions from old and new incinerators
Phase out waste incineration
Replace lead pipes and plumbing fixtures containing lead solder
Test blood for lead by age 1
Remove leaded paint and lead dust from older houses and apartments
Ban use of lead solder
Remove lead from TV sets and computer monitors before incineration or land disposal
Ban use of lead in computer and TV monitors
Figure 22.24
Solutions: ways to help protect children from lead poisoning. QUESTION: Which two of these solutions do you think are the most important?
Test for lead in existing ceramicware used to serve food
Ban lead glazing for ceramicware used to serve food
Test existing candles for lead
Ban candles with lead cores
Wash fresh fruits and vegetables
Fig , p. 541

32. Case Study: Mercury
Mercury is released into the environment mostly by burning coal and incinerating wastes and can build to high levels in some types of fish.
Figure 22-26

33. Solutions Mercury Pollution Prevention Control  
Phase out waste incineration
Sharply reduce mercury emissions from coal-burning plants and incinerators
Remove mercury from coal before it is burned
Convert coal to liquid or gaseous fuel
Tax each unit of mercury emitted by coal-burning plants and incinerators
Switch from coal to natural gas and renewable energy resources such as wind, solar cells, and hydrogen
Collect and recycle mercury-containing electric switches, relays, and dry-cell batteries
Figure 22.26
Solutions: ways to prevent or control inputs of mercury into the environment from human activities—mostly through coal-burning plants and incinerators. QUESTION: Which four of these solutions do you believe are the most important?
Phase out use of mercury in all products unless they are recycled
Require labels on all products containing mercury
Fig , p. 543

34. Fig. 22-25, p. 542 AIR WINDS PRECIPITATION WINDS PRECIPITATION
Hg and SO2
Hg2+ and acids
Hg2+ and acids
Photo-
chemical
Human sources
Elemental
mercury
vapor
(Hg)
Inorganic mercury
and acids
(Hg2+)
Inorganic mercury
and acids
(Hg2+)
Coal-
burning
plant
Incinerator
Deposition
Runoff of Hg2+ and acids
Deposition
WATER
Large fish
Vaporization
Deposition
Small fish
BIOMAGNIFICATION
IN FOOD CHAIN
Deposition
Figure 22.25
Science: cycling of mercury in aquatic environments, in which mercury is converted from one form to another. The most toxic form to humans is methylmercury (CH3Hg+), which can be biologically magnified in aquatic food chains. Some mercury is also released back into the atmosphere as mercury vapor. QUESTION: What is your most likely exposure to mercury?
Phytoplankton
Zooplankton
Bacteria
and acids
Oxidation
Elemental
mercury liquid
(Hg)
Inorganic
mercury
(Hg2+)
Organic
mercury
(CH3Hg+)
Bacteria
Settles
out
Settles
out
Settles
out
SEDIMENT
Fig , p. 542

35. 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.

36. 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.

37. 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.

38. Animation: Economic Types
PLAY
ANIMATION