In Europe, some plants combine electricity generation with a district heating system, using the excess steam to create heat used to heat homes. Waste is stored in large bunkers, then transported to a moving grate in a furnace where it is burned at over 850˚C for at least two seconds to ensure complete combustion. The heat from the furnace heats water in a boiler, creating steam that turns a turbine to drive a generator that makes electricity. Most of these plants are mass burn facilities. Europe has over 400 such plants, and another 300 are found in other parts of the world. In the U.S., there are currently 77 waste-to-energy facilities in 22 states, processing 95,023 tons of waste each day, capable of generating 20,800 gigawatt hours of electricity a year. In 2007, EPA compared waste-to-energy emissions between 19 it found decreases of 24 percent in nitrogen oxide, 88 percent in sulfur dioxide, 99 percent in dioxins and 96 percent in mercury. Environmental Protection Agency established the Maximum Achievable Control Technology regulations, which required waste-to-energy facilities to install air pollution controls. After the Clean Air Act came into effect, it became clear that the plants were producing dangerous mercury and dioxin emissions standards were established that banned uncontrolled burning of waste and limited emissions of particulate matter. Plants that burn waste to produce electricity were first constructed in the 1970s. Burning the waste in waste-to-energy plants not only reduces its volume by 87 percent, but can also harness its embedded energy and put it to good use. Landfilling solid waste brings with it the problems described above, and also means that all the energy inherent in the waste is squandered. Moreover, landfills are unsightly and odorous.Ī landfill in Danbury, Conn. Landfill gases can also move underground, potentially causing fires and explosions, and the liquid or leachate that accumulates in landfills can contaminate groundwater. In the U.S., they are the third largest contributor of methane emissions, whose global warming potential is 25 times more potent than carbon dioxide’s over 100 years. Landfills can emit carbon dioxide, methane, volatile organic compounds and other hazardous pollutants into the air. landfills has decreased over the years, but the average size of existing landfills has increased. This is followed by combusting the post-recycled waste for energy and then finally, landfilling. The next best option is to recycle composting organic waste comes next. The first priority is to avoid producing waste by reducing consumption and packaging. A key principle of sustainable waste management is to try to deal with waste as high up on the waste hierarchy as possible. No single approach can handle all types of waste, so a “hierarchy of waste management” is used to rank the strategies of dealing with waste according to their environmental impacts. Municipal solid waste consists of paper, cardboard, food, grass clippings, leaves, wood, leather, plastics, metals and petroleum-based synthetic materials. About 87 million tons of this was either composted or recycled, 32.7 million tons were burned for energy and 134.3 million tons went to landfills. produced 254 million tons of garbage, or municipal solid waste. And according to the World Resources Institute “one half to three quarters of annual resource inputs to industrial economies is returned to the environment as wastes within just one year.” Over the last four decades, we human beings have tripled our consumption of the earth’s natural resources, said a recent report from the United Nations Environment Programme.
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