2075347
Descrição
FlashCards por sabrinapar22, atualizado more than 1 year ago
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Criado por sabrinapar22
mais de 9 anos atrás
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| Questão | Responda |
| waste | -outputs not useful or consumed, non useful products generated within the system |
| What are examples of inputs in human systems? | raw materials, energy |
| What are examples of outputs in human systems? | -waste energy, material that can be recycled or disposed of |
| What caused consumption patterns in the United States to change? | -rapid population growth after WW II -increased industrialization -wealth -cultural changes |
| planned obsolescence | the design of a product so that it will need to be replaced within a few years |
| municipal solid waste MSW | refuse collected by municipalities from households, small businesses, institutions (schools, prisons), municipal buildings, and hospitals -60% MSW from residences -40% MSW from commercial and institutional facilities |
| What factors vary waste generation? | -season of the year -socioeconomic status of the individual -geographic location |
| waste stream | -flow of solid waste that is recycled, incinerated, placed in a solid landfill, or disposed of in another way |
| paper in solid waste stream | -newsprint, office paper, cardboard, boxboard -31% of waste stream -231 million metric tons (254 million US tons) -decreased from 40% |
| organic materials in the solid waste stream | -yard waste and food scraps 26% of MSW -wood 7% of MSW |
| plastic in solid waste stream | -12% MSW |
| compostable goods | -largely made up of organic material that can decompose under proper conditions |
| containers and packaging in solid waste stream | 31% of MSW -intended for one use |
| food and yard waste in the solid waste stream | -26% of MSW |
| non durable goods in the solid waste stream | 25% MSW -newspapers, white paper, printed products, plastic items |
| durable goods in the solid waste stream | -18% of MSW -appliances, tires, other manufactured products |
| E-waste in the waste stream | -2% -televisions, computers, cell phones |
| How is e-waste dangerous to the environment? | -contains heavy metals such as mercury, cadium -little infrastructure to recycle |
| reduce | -optimal way to reduce solid waste generation -waste minimization or prevention -reduced input = reduced output |
| source reduction | -reduction of wast by reducing the use of materials in the early stages of design and manufacture -increase energy efficiency -economic benefits -implemented on both individual or corporate levels |
| reuse | -allows a material to cycle within a system longer before becoming an output |
| recycling | -process by which are collected and converted into raw materials that are then used to produce new objects -rates increased in US since 1975 -US recycles 1/3 of MSW -requires more energy than reducing or reusing |
| closed loop recycling | -recycling of a product into the same product -eg aluminum cans made into new aluminum cans |
| open loop recycling | -one product is recycled into another product -eg plastic soda bottle is recycled into polar fleece jackets -does not reduce demand for raw material |
| What are the two problems of organic materials in landfills? | -take up space -absence of oxygen causes material to decompose anaerobically and produce methane gas |
| compost | organic matter that has decomposed under controlled conditions to produce an organic-rich material that enhances soil structure, cation exchange capacity, and fertility |
| What materials are compostable? | vegetables, vegetable by-products such as cornstalks, grass, animal manure, yard wastes, and paper fiber |
| What is the process of composting? | 1. detritivores break down dead tissues and waste products into smaller particles 2. decomposers complete the breakdown process by recycling nutrients from dead tissues and wastes back into the ecosystem 3. frequent turning for aerobic decomposition |
| What carbon to nitrogen ration best supports rapid decomposition? | 30:1 -layers of brown material and green material |
| How do large scale composting facilities operate? | 1. waste us dumped in a tipping area 2. compostable and noncompostable materials are separated 3. noncompostable material is removed to landfill 4. compostable material is aerated and turned one or more times for a period of 30 days to a year 5. composted material is allowed to cure 6. finished compost is transported for use |
| leachate | -water that leaches through the solid waste and removes various chemical compounds which it comes into contact |
| sanitary landfills | engineered ground facilities designed to hold MSW with as little contamination of the surrounding environment as possible |
| What are the layers of sanitary landfills? | -clay/plastic lining at bottom -pipes constructed below to collect leachate -cover of soil and clay (cap) at top when landfill reaches capacity |
| Why is rainfall and other water inputs minimized in sanitary landfills? | -cause greater rate of anaerobic decomposition and methane release -greater likelihood of leachate |
| What types of waste should not go in a landfill? | aluminum and other metals, toxic materials, organic materials -anything that contains substantial quantities of metals |
| Process of a landfill | 1. solid waste transported to the landfill 2. waste is compacted by a specialized machine 3. leachate collection system removes water and contaminants and carries them to a wastewater treatment plant 5. methane produced in closed cells is extracted and either burned off or collected for use as fuel |
| How are landfill construction fees recovered? | -tipping fees: fee charged for disposing of material in a landfill or incinerator |
| Where should a sanitary landfill be located? | -soil rich in clay -away from rivers, streams, and other water bodies -far from population centers, but not to far |
| What problems are caused by landfills? | -locating landfills near populations who do not have the resources to object -possibility of leachate contaminating water -anaerobic decomposition produces greenhouse gases and explosion hazards |
| incineration | process of burning waste materials to reduce the volume and mass and sometimes to generate electricity or heat -efficient incinerators may reduce the volume of solid waste by 90% and weight by 75% |
| Process of mass burn MSW incinerator | 1. MSW sorted, recyclables diverted 2. remaining material is tipped into refuse bunker and certain materials are removed 3. crane transfers waste from bunker to hopper 4. waste burned in incineration chamber and combustion releases water and CO2 5. ash is collected and removed from plant 6. baghouse filter cleans air before it is released through chimney 7. heat energy can be used to create steam and generate electricity |
| ash | residual nonorganic material that does not combust during incineration |
| bottom ash | residue collected underneath the furnace |
| fly ash | residue collected beyond the furnacr |
| waste to energy | -heat generated by incineration is used rather than released to the atmosphere |
| What are the problems with incineration? | -higher tipping fees ($70 per ton) -NIMBY and environmental justice issues -air pollutants -concentrated and toxic ash -large and expensive to build -require large daily MSW amounts to be efficient and profitable=less likely to encourage recycling -,ay not completely burn all waste |
| hazardous waste | -liquid, solid, gaseous, or sludge waste that is harmful to humans or ecosystems |
| What are some sources of hazardous waste? | industrial processes, dry cleaners, automobile service stations, small farms, households |
| Resource Conservation and Recovery Act RCRA | -1970s -protect human health and environment by reducing or eliminating generation of hazardous waste -EPA maintains lists of hazardous wastes and works with businesses and state/local authorities to minimize and track hazardous waste -modified in 1984 to Hazardous Solid Waste Amendments HSWA to encourage waste minimization and phase out disposal of hazardous wastes on land, increase punishment of violators |
| Comprehensive Environmental Response, Compensation, and Liability Act CERCLA (Superfund Act) | -passed 1980 amended 1986 -tax on chemical and petroleum industries -revenue from tax used to fund cleanup of abandoned and nonoperating hazardous waste sites -fed gov can respond directly to release or threat of release of toxic substances -National Priorities List NPL of contaminated sites eligible for funds |
| Brownfields Program | -assists state and local gov in cleaning up contaminated land that did not achieve conditions necessary to be in Superfund category -brownfields: contaminated industrial or commercial sites that may require environmental cleanup before they can be redeveloped or expanded -management varied from region to region since it is run by state and local govs |
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