Chapter 22: Waste Management
Testing Your Comprehension:
1) There are five major methods of managing wastes. Minimizing waste at its
source, otherwise known, as source reduction is the preferred approach. The ways
to reduce the amount of waste that enters the waste stream are: manufacturers can
use materials more efficiently. Consumers can buy fewer goods, buy goods with
less packaging, and use those goods longer. Reusing goods that you own,
purchasing used items, and donating your used item for others also help reduce
the amount of material entering the waste stream. Recovery (recycling and
composting) is the next best strategy in waste management. Mostly the ways to
reduce waste are: make industrial practices more efficient, minimize packaging
for products, purchase “green” consumer products, reuse items, recycle items,
compost materials at home, municipal composting. The other ways to reduce
waste would be: dump waste in landfill or use put wastes in the incinerator. We
practice waste management as a means to minimize the impact on human health
and the environmental quality. Waste can degrade water quality, soil quality and
air quality, thereby degrading human health and the environment. Waste is also a
measure of inefficiency, so reducing waste can potentially save industry,
municipalities, and consumers both money and resources. Waste is also
unpleasant physically, so due to these and other reasons, waste management is
crucial.
2) Due to the relative wastefulness of the U.S. lifestyle, with its excess packaging
and reliance on nondurable goods, it has caused critics to label the U.S. as “the
throwaway society”. The amount of solid wastes that Americans generate is 246
million tons of municipal solid wastes, around 1 ton per person. Following the
U.S. in per capita solid wastes generation are Canada, with 1.7 kg per day and the
Netherlands with 1.4 kg. per day. Among the developed nations, Germany and
Sweden produce the least waste per capita, generating just under 0.9 kg. per day.
Differences among nations result in part from differences in the cost of waste
disposal, where disposal is expensive, people have incentive to waste less. In
developing nations, people consume less and generate considerably less waste.
However, wealthier nations also invest more in waste collection and disposal, so
they are often better able to manage their waste proliferation and minimize
impacts on human health and the environment.
3) The guidelines by which sanitary landfills are regulated are:
-The U.S. requires that landfills be located away from wetlands and earthquakeprone faults and be at least 6 meters above the water table.
-The bottoms and sides of sanitary landfills must be lined with heavy-duty plastic
and 60 to 120 cm of impermeable clay to help prevent contaminants from seeping
into aquifers. Sanitary landfills also have systems of pipes, collection ponds, and
treatment facilities to collect and treat leachate, liquid that results when substances
from the trash dissolve in water as rainwater percolates downward.
-Landfill managers are required to maintain leachate collection systems for 30
years after a landfill has closed.
-Area groundwater has to be monitored regularly for contamination.
-After a landfill is closed, it should be capped with an engineered cover that must
be maintained. This cap should consist of a hydraulic barrier of plastic that prevents
water from seeping down and gas from seeping up, a gravel layer above the hydraulic
barrier that drains water, lessening pressure on the hydraulic barrier; a soil barrier of
at least 60 cm. that stores water and protects the hydraulic layer from weather
extremes, and a topsoil layer of least 15 cm. that encourages plant growth, helping to
prevent erosion.
Three problems with landfills are:
-The leachate will eventually escape even from well-lined landfills. Liners can be
punctured and leachate collection systems eventually cease to be maintained.
-Landfills are kept dry to reduce leachate, but the bacteria that break down material
thrive in wet conditions. Dryness, therefore, slows waste decomposition.
-Being able to find suitable areas to locate landfills because most communities do not
want them. Most communities reject the idea of having landfills near their housing
areas, since landfills pose many problems with human health and sanitation.
4) The process of incineration/combustion is a controlled process in which mixed garbage
is burned at very high temperatures. At incineration facilities, waste is generally sorted
and metals removed. Metal-free waste is chopped into small pieces to aid combustion and
then is burned in a furnace. Incinerators reduce the volume of solid waste by burning it
but may emit toxic compounds into the air. Many incinerators are waste-to-energy
facilities that use the heat of combustion to generate electricity. In a waste-to-energy
facility, waste is (one), burned at extremely high temperatures, (two), heating water,
which turns to steam. The steam turns a turbine (three) which powers a generator to
create electricity. In an incinerator outfitted with pollution-control technology, toxic
gases produced by combustion are mitigated chemically by a scrubber, (four) and
airborne particulate matter is filtered physically in a baghouse, (five) before air is emitted
from the stack. (six) Ash remaining from the combustion process is disposed of (seven)
in a landfill.
The resulting ash is then thrown in a landfill. One drawback of incineration is that
revenues from power generation are usually not enough to offset the considerable
financial costs of building and running incinerators. It can take many years for a wasteto-energy facility to become profitable, since many companies that build and operate
these facilities require communities contracting with them to guarantee the facility a
minimum amount of garbage.
5) Composting is the conversion of organic waste into mulch or humus through natural
biological processes of decomposition. The compost can then be used to enrich soil.
Householders can place waste in compost piles, underground pits, or specially
constructed containers. As wastes are added, heat from microbial action builds in the
interior, and decomposition proceeds. Banana peels, coffee grounds, grass clipping,
autumn leaves, and countless other organic items can be converted into rich, high quality
compost through the actions of earthworms, bacteria, soil mites, sow bugs, and other
detritivores and decomposers. Home composting is a prime example of how we can live
more sustainably by mimicking natural cycles and incorporating into our daily lives.
Municipal composting programs divert food and yard waste from the waste stream to
central composting facilities, where they decompose into mulch that community residents
can use for gardens and landscaping. Composting reduces landfill wastes, enriches soil
and helps it resist erosion, encourages soil biodiversity, makes for healthier plants and
more pleasing gardens, and reduces the need for chemical fertilizers.
6) The three elements of a sustainable process of recycling are:
-Collection and processing of recyclable materials by municipalities and businesses.
-Use of recyclables by industry to manufacture new products.
-Consumer purchase of products made from recycled materials.
7) The goals of industrial ecology are: seeking to redesign industrial systems to
reduce resource inputs and to minimize physical inefficiency while maximizing
economic efficiency, reshape industry so that nearly everything produced in a
manufacturing process is used, either within that process or in a different one.
Industrial ecologists also want: industrial systems should function more like
ecological systems in which everything produced is used by some organism, with
very little being wasted. This principle brings industry closer to the ideal of
ecological economists, in which human economies attain sustainability by
functioning in a circular fashion rather than a linear one. They want to be able to
examine the entire life cycle of a given product and look for ways to make the
process more ecologically efficient. This strategy is called life-cycle analysis.
8) The four criteria used to define hazardous wastes are:
a. Ignitable: substances that easily catch fire (for example, natural gases or
alcohol)
b. Corrosive: substances that corrode metals in storage tanks or equipments.
c. Reactive: substances that are chemically unstable and readily react with
other compounds, often explosively or by producing noxious fumes.
d. Toxic: substances that harm human health when they are inhaled, are
ingested, or contact human skin.
Heavy metals and synthetic organic compounds are particularly hazardous
because they resist decomposition, which makes them persistent pollutants.
Many synthetic organic compounds are toxic because they can be readily
absorbed through the skin of humans and other animals and can act as
mutagens, carcinogens, teratogens, and endocrine disruptors. Heavy metals
are widely used in industries. Heavy metals enter the environment when
substances and things are disposed of improperly. Lead from fishing weights
are accumulating in rivers, lakes and streams. Heavy metals that are fatsoluble and break down slowly are prone to bioaccumulate.
9) The largest sources of hazardous wastes are produced by the industry. Households
are the largest source of unregulated hazardous wastes. Three ways to dispose
hazardous wastes are: landfills, surface impoundments, and injection wells.
Hazardous waste landfills must have several impervious liners and leachate
removal systems and must be located far from aquifers. Dumping of hazardous
wastes in ordinary landfills has long been a problem. Liquid hazardous wastes or
waste in dissolved form may be stored in ponds or surface impoundments shallow
depressions lined with plastic and an impervious material, such as clay. Water
containing dilute hazardous waste is placed in the pond and allowed to evaporate,
leaving a residue of solid hazardous waste on the bottom. This process is repeated
until the dry material is removed and transported elsewhere for permanent
disposal. Impoundments are not ideal. The underlying layer can crack and leak
waste. Some material may evaporate or blow into surrounding areas. Rainstorms
may cause waste to overflow and contaminate nearby areas. For these reasons,
surface impoundments are used only for temporary storage. Deep-well injection is
intended for long-term disposal. In this deep-well injection, a well is drilled deep
beneath the water table into porous rock and wastes are injected into it. The waste
is meant to remain deep underground isolated from groundwater and human
contact. This idea may seem good in principle, but in practice wells become
corroded and can leak wastes into soil, allowing them to enter aquifers.
10) The superfund program is a federal program that helps clean up U.S. sites
polluted with hazardous wastes from past activities. The EPA administers this
cleanup program, Superfund. Under EPA auspices, experts identify sites polluted
with hazardous chemicals, take action to protect groundwater near these sites and
clean up the pollution. Later, laws also charged the EPA with cleaning up
brownfields, lands whose reuse or development are complicated by the presence
of hazardous materials. Once a superfund site is identified, EPA scientists
evaluate how close the site is to human habitation, whether wastes are currently
confined or likely to spread and whether the site threatens drinking water
supplies. Sites that appear harmful are placed on the EPA’s National Priority List,
ranked according to the level of risk to human health that they pose. Cleanup
proceeds on a site-by-site basis as funds are available. Throughout the process, the
EPA is required to hold public hearings to inform area residents of its findings
and to receive feedback. The cleanup involves trying to isolate waste from human
contact, either by building trenches and clay or concrete barriers around a site or
by excavating contaminated material, placing it in industrial –strength containers,
and shipping it to a hazardous waste disposal facility.
Seeking Solutions:
1) In my family, we don’t generate a lot of waste, compared to the average American
family because I think we consume less, so there’s less to discard. On an average
day, we throw away about one whole shopping bag full of garbage. Most of the
garbage is 2/3 food related sources. The other part of the garbage is just 1/3 of
different trashes such as plastic, paper, and other things. The other wastes I may
have generated are: kitchen disposal wastes, human wastes, and water waste. The
wastes I could have avoided generating would be paper, plastic and reusable
wastes. The paper, plastics, and kitchen disposal could have been reused. I could
have taken the kitchen disposal waste and used that for as compost. Which would
be more “green” towards the environment.
3) The waste management that my community is using would be the landfill,
incinerator, recycling, and reusing management methods. They are not pursuing the
other waste managements such as composting. Composting generally isn’t such a
popular idea. I think, with the methods that my community is using now, I don’t have
any other suggestions to my community, except to start composting for the sake of
our environment. This will only benefit our environment and help the natural cycles
proceed. We can reduce a lot of the wastes that we throw away and even help the
natural cycles with composting food wastes.
4) No, manufacturers would not benefit from source reduction if consumers were to
buy fewer products. This is because, with consumers spending less on products
that these manufacturers make, the manufacturers would not make much profit.
They could even lose profit and it would cause economic chaos. Given what I
know about industrial ecology, I think that the future of sustainable manufacturing
may look very bright. I think industries will began using the methods of the
industrial ecologists and incorporate that into their own industry manufacturing
method. Industries will start using the life-cycle analysis as a way to improve the
manufacturing process with environmentally friendly products. Since there’s been
global warming, and all sorts of problems with the environment now, industries
are probably thinking like consumers, about the ways that they can efficiently
produce and make profits by also helping the environment reduce problems.
5) The steps that I would consider taking are:
-Managing the resources well, and improvising the management of the wastes
-I would discuss with my corporation and devise certain methods such as changing
the way our containers are made, so that there is less use of hazardous materials used
to make the containers and products that we sell.
-I would try to think of eco-friendly ways that we can make our products seem, and
advertise that to persuade consumers to purchase them, yet at the same time tell them
our products are less damaging to the environment.
-Make ways to decrease the supply, so there’s less to waste and be disposed of.
Interpreting Graphs and Data:
2) Income Category of Nations:
Pounds MSW Per Capita Per Day:
Low
Low-Middle
Upper-Middle
High
All economies
1.17
1.39
1.55
2.64
1.47
4) I think it may be possible for wealthier nations to reduce their per capita MSW
generation to the rates of poorer nations as long as they can find some way to sustain
smaller amounts of wastes that they generate. There is always a way for impossible
things to happen, as long as there are methods that allow the impossible actions to
become possible. Wealthier nations just need to think up of ways in which they can
reduce the amount of waste they generate. They can either start recycling more of the
materials that they most likely throw away or they can start composting the things that
they can throw into composts to help natural cycles.