1
Why is it said that waste is a “human invention”? What kind of solid waste do humans produce, and how does its production compare between countries of different developmental levels and income?
INFOGRAPHIC 7.1
All of the following are consistent with the law of conservation of matter except
there is no such thing as waste.
matter is neither created nor destroyed, but it can change form.
if we encounter dangerous matter that we don’t want around, we can destroy it.
one organism’s waste matter is taken up by another organism and reused.
C
Distinguish between degradable, biodegradable, and nondegradable waste. How well do plastics degrade?
These 3 categories differ in the degree or manner in which waste can be broken down to another form. Waste that is degradable can be broken down by physical or chemical means; biodegradable waste can be broken down by living organisms. Waste that is nondegradable resists being broken down at all and may persist in its original form. Plastics do not degrade easily — they are chemical stable and require exposure to UV light in an oxygen rich environment to start the process of breaking apart. Few, if any, microbes digest plastics so they are generally not considered to be biodegradable.
How does waste generation relate to developmental status of countries? Why do you suppose that the regions with the highest per capita waste generation produce so much more waste than other regions?
The more developed a country is, the more waste it produces per person. This probably reflects excess income that can be used to buy more products and to buy products that are more processed and packaged. In lower income areas discarded items are more likely to be reclaimed and reused or recycled as well.
2
What options do we have for dealing with solid waste, and what are the trade-offs for each option?
INFOGRAPHIC 7.2, INFOGRAPHIC 7.3 AND INFOGRAPHIC 7.6
True or False: Garbage decomposes more quickly in a sanitary landfill than it would in an open dump.
FALSE
Which of the following statements about incinerators is false?
Incinerators reduce the volume of material that needs to be landfilled.
Incinerators are expensive to build and operate.
The heat released during burning reduces the toxic and hazardous materials in the waste stream.
Burning solid waste in incinerators can produce energy.
C
Compare and contrast landfilling and composting. What are the trade-offs for each option?
In both, trash is allowed to decompose but the similarity ends there. Landfilled trash decomposed very slowly because water and air are excluded. This favors anaerobic bacterial breakdown which is very slow and produces methane as a byproduct. Composting puts the trash under conditions that favor aerobic bacteria and maximize decomposition rates. The result is a mulch-like soil that can be used to improve soil quality. Landfills do not produce a usable soil product but the methane can be harvested and used to produce electricity. A compost facility or area can be used indefinitely because of the fast rate of decomposition (assuming the resulting compost is removed and used). A landfill must be retired once full and may not be suitable for all land uses due to the potential presence of hazardous material buried in the landfill.
3
What are some of the negative consequences of solid waste pollution?
INFOGRAPHIC 7.4
Which of the following is a consequence of uncollected waste?
Air pollution
Water pollution
Flooding
A and B
A, B, and C
E
In what ways does the plastic trash in oceans harm ocean life?
Animals can get trapped by larger plastic debris; they may ingest smaller pieces that might cause choking, obstruction of their gut or poisoning. Plastic may also serve as attachment points for sea life, transporting species out of their natural ranges — this may be harmful for the sea life transported but more likely introduces new species to an area which may disrupt normal ecosystems.
From an economic point of view, why is solid waste considered a mismanagement of resources?
Resources that are buried or lying in open dumps or burned to ash may no longer be readily available to be re-used and recycled. This reduces the matter available both to organisms in ecosystems and manufacturers looking for raw materials for production.
4
What is hazardous waste, and what can the average person do to reduce his or her production of it?
INFOGRAPHIC 7.5
True or False: Hazardous waste is an industrial waste issue and is not a problem for MSW.
FALSE
What is e-waste, and why is it a concern?
E-waste is electronic waste — discarding any electronic device with a circuit board such as computers, printers, cell phones, video consoles, etc. These devices contain toxic heavy metals and if not disposed of and recycled properly can expose workers or people living near the disposal sites to dangerous levels of these hazardous materials.
Identify some hazardous substances in your home.
Answers will vary but could include cleaners, fluorescent light bulbs, lawn and garden chemicals, automotive chemicals, glues, and paints.
5
How can industry and individuals reduce the amount of waste they produce?
INFOGRAPHICS 7.6, 7.7, AND 7.8
True or False: Any vegetable based kitchen or yard scraps can be added to a compost pile but you should avoid adding meat and bones.
TRUE
The best solutions to managing waste include which one of the following?
Source reduction and application of natural decomposition processes
Supporting the siting of a landfill in your community to reduce waste transportation costs
Disposing of hazardous waste in oceans, as the water dilutes the waste
Shipping electronic waste to developing countries to provide jobs there in extracting precious metals from the electronic devices
A
An industrial ecologist’s goals would not include:
increasing resource-use efficiency by altering manufacturing processes.
designing products that are durable and can be demanufactured.
identifying points in the product life cycle at which waste products can be used in other processes.
identifying points in the product life cycle at which waste products can be landfilled.
D
Explain what is meant by the four Rs, in order of preference, and give an example of each.
The 4 Rs are steps that can be taken to reduce the overall MSW generated by an individual. In order of preference they are:
Refuse: don’t use a product if not needed (i.e. don’t buy bottled water if tap water is available).
Reduce: if you cannot refuse an item, then use the least amount possible (i.e. if you buy a bottle of water, refill it if possible rather than tossing it and buying another [but do so only a limited number of times to avoid exposure to chemicals in the plastic]).
Re-use: Use items again to extend their life (i.e. purchase a reusable bottle for water and use it again and again; reuse disposable bottles for craft projects or as storage containers).
Recycle: turn the item in for reprocessing (i.e. drop the bottle off at a recycling bin after its useful life is over).
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