3. Leaving a Mark on the World
• Have you ever seen very old photographs of
the town or city in which you now live?
• Has your area changed?
• Perhaps there are more buildings or roads
than there were many years ago. Maybe your
town or city has more trees and flowers now
than it had years ago. Humans, like all
organisms, have an effect on their
environment.
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4. Leaving a Mark on the World
• Earth is a kind of island
• Limited resources
• Nature must sustain the resources
• Human populations is growing
• The planet is not
5. Leaving a Mark on the World
• Demands on
– Air
– Water
– Land
– Living things
6. Leaving a Mark on the World
• We must protect these resources
• What human activities do you think have an
impact on the earth’s natural resources?
– Hunting and gathering
– Agriculture
– Industry
– Urban development
7. Leaving a Mark on the World
• Recent study concluded that human activity uses
as much energy as all of earth’s other
multicellular species combined
• Humans are the most influential in changing the
environments of the planet
8. WASTE
• regarded as useless and unwanted (at a certain
time and place)
INDUSTRIAL PRODUCTION
– changes the natural cycle of materials
– uses more and more materials
– produces an ever increasing amount of waste
9. PROBLEMS
• We throw away a lot of material and energy
present in waste
• We produce waste having a changed
composition and characteristics as the raw
materials used
• We pollute and poison the environment
10. PROBLEMS CAUSED BY
IMPROPER DISPOSAL OF WASTE
Threat to public health
- rodents, insects = vectors of diseases (transmit
pathogens)
typhoid, plague
- poisonous materials
- flammable materials
Irreversible environmental damage in ecosystems
- terrestrial and aquatic
- air pollution (incineration)
- water pollution (land burial)
Technical and environmental difficulties + administrative,
economic and social problems
11. PROBLEMS WITH LAND
DISPOSAL OF WASTE
too little space for disposal
costs
harm to the environment and public health
landfills are unreliable in long run
aesthetics
public opposition
14. Waste Management
- is the generation, prevention, characterization,
monitoring, treatment, handling, reuses and
residual disposition of solid wastes.
Solid Waste
- Is generally made up of objects or particles that
accumulate on the site where they are produced.
Various Types of Solid Waste
1. Municipal solid waste
2. Hazardous waste
3. Agricultural waste
4. Industrial solid waste
16. We have several aims in
managing waste
• Three main components of waste
management
– Minimizing the amount of waste we generate
(source reduction)
– Recovering waste materials and finding ways
to recycle them
– Disposing of waste safely and effectively
18-16
18. We have several aims in managing
waste
• Waste stream = flow of waste as it moves from its
sources toward disposal destinations
– More efficient use of materials, consume less, buy goods
with less packaging, reusing goods
• Recovery (recycling, composting) = next best
strategy in waste management
– Recycling = sends used goods to manufacture new
goods
– Composting = recovery of organic waste
18-18
21. Municipal Waste
• This type of waste comes from households,
commercial establishments, institutions, and some
industrial sources.
• Broken, spoiled, or have no further use materials.
18-21
24. Waste generation is rising in all nations
• Since 1960, waste generation has increased
in North America by 300%
– Plastic has accounted for greatest relative
increase
• Waste generation in Canada has kept pace
with population growth
• In many industrialized nations, per capita
waste generation rates have leveled off or
decreased in recent years
– Increase popularity of recycling
18-24
26. Hazardous/Mining Waste
• It is generated in 3 primary ways:
1. Separation of ore minerals from gangue minerals or
waste materials
2. Milling operation- the grinding and sorting of materials
produces solid waste called tailings.
3. Water is pumped from mine flows from piles of waste
water rock or tailings that contain hazardous
materials.
27. Organic compounds and heavy metals can be
hazardous
• Organic compounds
– are particularly hazardous because their toxicity persists
over time and synthetic organic compounds resist
decomposition
• Keep buildings from decaying, kill pests, and keep
stored goods intact
• Their resistance to decay causes them to be persistent
pollutants
• They are toxic because they are readily absorbed
through the skin
• They can act as mutagens, carcinogens, teratogens,
and endocrine disruptors
18-27
28. Organic compounds and heavy metals can be
hazardous (cont’d)
• Heavy metals
– Lead, chromium, mercury, arsenic, cadmium, tin, and
copper
– Used widely in industry for wiring, electronics, metal
plating, pigments, and dyes
– They enter the environment when they are disposed of
improperly
– Heavy metals that are fat soluble and break down slowly
are prone to bioaccumulation
18-28
29. “E-waste” is a new and growing
problem
• Electronic waste (e-waste) = waste involving
electronic devices
– Computers, printers, VCRs, fax machines, cell
phones
– Disposed of in landfills, but should be treated as
hazardous waste (6% of a typical computer is
composed of lead)
– Some people and businesses are trying to use
and reuse electronics to reduce waste
– Serious concerns about health risks to workers
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30. Several steps precede the disposal of
hazardous waste
• For many years, hazardous
waste was discarded without
special treatment
– Public did not know it was
harmful to human health
– Assumed the substances
would disappear or be diluted
in the environment
– Since the 1980s, cities
designate sites or special
collection days to gather
household hazardous waste
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32. Agricultural waste
• A common form of waste from the raising of
animals and the harvesting and processing of
crops and trees.
• Most agricultural waste is organic and is used for
soil-enhancement activities.
• When there is too much agricultural waste
produced in one area, runoff of ground water
contamination due to infiltration happens.
34. Industrial Solid Waste
• A waste coming from
sources other than mining.
• It includes a variety of
materials such as
demolition waste, scraps
from manufacturing
process, and from
combustion.
• If they are classified as
hazardous waste, the
disposal requires special
hazardous landfills.
36. Landfills
• Sanitary landfills = waste buried in the ground or piled in
large, engineered mounds
• Leachate = liquid that results when trash dissolves in water as
rainwater percolates downward
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37. Landfills can be transformed after
closure
• Many landfills lie abandoned
– Managers closed smaller landfills and made fewer
larger landfills
• Decommissioning = shutting down an industrial
site and getting it ready for cleanup and
repurposing
• Growing cities converted closed landfills into
public parks
– Rouge Park in Toronto
– Fresh Kills in New York
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38. Landfills have drawbacks
• Experts believe that leachate (toxic fluid) will eventually
escape
– The liner will become punctured
– Leachate collection systems eventually aren’t
maintained
• It is hard to find places suitable for landfills
– The Not-In-My-Backyard (NIMBY) syndrome
• The “garbage barge” case
– 1987: Islip, New York’s landfills were full, and a barge
traveled to empty the waste in North Carolina, which
rejected the load, as did Louisiana and Mexico
– It returned to Queens to incinerate the waste, after a
9,700 km journey 18-38
39. Landfills can produce gas for
energy
• Bacteria can decompose waste in an oxygen-
deficient environment
• Landfill gas = a mix of gases that consists of
roughly half methane
– Can be collected, processed, and used like natural gas
– When not used commercially, landfill gas is burned off in
flares to reduce odors and greenhouse emissions
• More than 40 operational projects in Canada collect
landfill gas and convert it into energy
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40. Surface impoundments
• Surface impoundments =
store liquid hazardous
waste
• Shallow depressions are
lined with plastic and clay
• Residue of solid hazardous
waste is transported
elsewhere
• The underlying clay layer
can crack and leak waste
• Rainstorms cause overflow,
contaminating nearby areas
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41. Deep-well injection
• Deep-well injection = a
well is drilled deep
beneath the water table
and waste is injected into
it
– Long-term disposal
– The well is intended to be
isolated from groundwater
and human contact
– Wells become corroded
and leak waste into soil
18-41
42. Incineration
• Incineration = a controlled process in which mixed
garbage is burned at very high temperatures; often
used in Europe to also generate energy; proposed
for Duke Point.
• Incineration in specially constructed faculties can be
an improvement over open-air burning of trash
– But, the remaining ash must be disposed of in a
hazardous waste landfill
– Hazardous chemicals are created and released
during burning
• Scrubbers = chemically treat the gases produced in
combustion to remove hazardous components and
neutralize acidic gases
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44. Many incinerators burn waste to create energy
• Waste-to-energy facilities (WTE) = use the
heat produced by waste combustion to create
electricity
– Waste generates about 35% of the energy
generated by burning coal
• Companies contract with communities to
guarantee a minimum amount of garbage
– Long-term commitments interfere with the
communities’ later efforts to reduce waste
18-44
45. Garbage justice?
• Do you know where your trash goes?
• Where is your landfill or incinerator located?
• Are the 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
neighbourhood protested against the introduction
of the landfill or incinerator?
weighing
the issues
18-45
46. Source Reduction
• Source reduction = preventing waste
generation in the first place
• Avoids costs of disposal and recycling
• Helps conserve resources
• Minimizes pollution
• Can save consumers and businesses money
• Strategies
– Reduce packaging
– Ban or per-bag charges for plastic grocery bags
– Increase the longevity of goods
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47. Reuse is one main strategy for waste reduction
• Donate used items to charity
• Reuse boxes, paper, plastic, wrapping paper, and
so on
• Buy groceries in bulk
• Decline bags at stores and bring cloth bags
shopping
• Bring your own cup to coffee shops
• Buy rechargeable batteries
• Select goods with less packaging
• Compost kitchen and yard wastes
• Rent or borrow items instead of buying them 18-47
48. Reducing Packaging: Is It A Wrap?
Reducing packaging cuts down on the waste stream,
but how, when, and how much should we reduce?
Packaging can serve very worthwhile purposes, such
as safeguarding consumer health and safety.
• Can you think of three products for which you would
not want to see less packaging?
•Can you name three products for which packaging
could easily be reduced without ill effects to the
consumer?
•Would you be any more or less likely to buy these
products if they had less packaging?
weighing
the issues
18-48
50. Recycling has grown rapidly and can expand
further
• 95% of Canadian households have access to
recycling programs
• Recycling rates vary from one product or material
type to another and from one location to antoher
• Increase has been driven by
– Economic forces
– Desire to reduce waste
18-50
51. Costs of Recycling and
Not Recycling
• Should recycling programs be subsidized by
governments even if they are run at an economic
loss?
• What types of external costs—costs not reflected
in market prices— do you think would be
involved in not recycling, say, aluminum cans?
• Do you feel these costs justify sponsoring
recycling programs even when they are not
financially self-supporting? Why or why not?
weighing
the issues
18-51
52. Financial incentives can help
address waste
• Pay-as-you-throw = uses financial incentives
to influence consumer behavior
– The less waste a house generates the less it is
charged for trash collection
• Return-for-refund = consumers pay a deposit,
and receive a refund for returning used bottles
– Greatly reduced beverage container litter
– All provinces and territories in Canada except for
Nunavut
18-52
53. Edmonton showcases reduction and recycling
• Edmonton, Alberta, has
created one of the
world’s most advanced
waste management
programs
– Waste: 35% sanitary
landfilled, 15% is recycled,
50% is composted
– 88% of the people
participate in curbside
recycling
18-53
54. Composting
• Composting = the conversion of organic waste
into mulch or humus through natural biological
processes of decomposition
• There are now more than 350 centralized
composting programs in Canada
• 28% of the Canadian solid waste stream is
made up of materials that can easily be
composted
• 57% of Canadian households do some form of
composting 18-54
55. Conclusion
• Modern methods of waste management are far
safer for people and gentler on the environment
• Recycling and composting are making rapid
progress
• Canada has changed from virtually no recycling
to diverting nearly 25% of all solid waste
• Our prodigious consumption habits have created
more waste than ever before
• Finding ways to reduce, reuse and efficiently
recycle the materials and goods that we use
stands as a key challenge for this century
18-55
