Waste is a concept. Whenever a system creates an output with no use, that output is waste. There are ways to classify waste such as solid (typically a solid, but possibly a liquid), municipal (from households, schools, businesses) or hazardous (acutely toxic and dangerous, requiring stronger management techniques: heavy metals, radioactive waste, dioxins and PCB’s,etc.) waste. However, air pollution is a form of waste, as is energy wasted when you exercise, which is one possible convergence that human systems have with “natural systems” where “waste”, or solid waste, is hard to impossible to find. Our scale of solid waste is enormous in the United States: over 10 billion tons/year. About 2%, or over 220 million tons/year comes from municipal sources, which equals out to more than 4 lbs/person/day. But again, the US emits more than 6 billion tons of carbon dioxide gas/year. Our powerplants, homes and vehicles routinely perform at levels of 30% efficiency or less. That is to say many traditional systems waste 70% or more of inputted energy. Another way to look at our waste levels is to imagine that for every truck load of lasting materials we produce, 32 truckloads of waste are produced.
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- Waste Incineration
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- Wheelabrator Turbine
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- Wheelabrator Pit
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- Waste Water
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- Paper Recyclers
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- Composting
Municipal waste is primarily managed through Landfills, recycling, or incineration. Each present benefits and drawbacks. In landfills pollutants can leach through soil to contaminate groundwater or release methane due to anaerobic breakdown of organic matter. The methane can be recaptured and burned to drive steam-powered turbine electricity generation. While lining and capping a landfill with sand, clay, and plastic can prevent leachate pollution. Incineration takes “waste” and turns it into a fuel to be burned for powering a turbine as well, while reducing the need for landfill space and long-range transportation solid waste. Further, plants are able to recycle metals from the ash. The drawbacks are the range and volume of pollutants from dioxins to mercury, and from NOx to PM. Filtration steps are taken such as using urea for the NOx, fabric filters or electrostatic precipitators for PM, and carbon injection to absorb mercury. Other issues include managing the fly and bottom ash, formed by combustion, that contain high concentrations of heavy metals and other toxins, and that require landfilling.
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Recycling turns items into non-waste inputs for production of glass bottles, cardboard, decking/fencing, clothes, construction metals, etc. Many items such as aluminum or copper are easily recycled and save 85% or more energy than would be used to extract ore from the ground. However, recycled paper and plastics, though they save energy, do not maintain their quality after numerous rounds of recycling.
Cities like San Francisco have led the way with municipal recycling programs, achieving rates up to 75%. Residents have to pay for pick up of “trash” bags but not for compost or recyclables. The city of Worcester pushes up towards 50% through a similar resident collection system, the difference being compost is not picked up, but residents can purchase a compost bin for $25 (www.ci.worcester.ma.us : go to city dpts/public works/misc) So the recycling rate may be harder to quantify.
Electronic or “e”-waste has become one of the most destructive waste systems known to man due to the toxins involved in construction and function of electronics (cadmium, lead, mercury, etc.), the rate of product turnover (the US. throws away 130,000 computers each DAY), and the waste managment which is often mis-managed in developing countries where parts, for instance, are burned down emitting one of the most toxic class of pollutants, dioxins, or allowed to leach out heavy metals into soil and water.
For more information watch the following video at : 60 Minutes Investigates E-Waste Recycling Catastrophe
Architect William McDonough is often credited with the concept of “cradle to cradle” whereby all systems are view in a way where inputs and output are inter-changeable and connected, non toxic, efficient, and sustainable. Waste no longer exists. Go to www.mbdc.com for more information
May 17, 2008 at 8:31 pm
Every year, the United States emits about ten billion tons of waste. Approximately, fifty-seven percent of the waste goes into landfills, (a permanent waste-disposal facility where wastes are put in the ground and covered each day with a layer of soil or plastic), twenty-eight percent of the waste is recycled, and fifteen percent is incinerated. There are different kinds of waste, for example, solid waste and municipal solid waste. Solid waste is defined as any discarded solid material. The top rankings of solid waste include materials like paper products. Paper products are the number one form of solid waste. Yard waste comes in second. Third is food waste. Finally, plastic products are fourth. The main reason for all of this waste is that all products that are produced are made of either two materials, biodegradable materials, or nonbiodegradable materials. Biodegradable materials can be broken down naturally by the environment, where nonbiodegradable materials cannot. For example, many plastic materials are made of petroleum or natural gas. Both of these materials consist of hydrogen and carbon. However when combined, they form chains that are not found in nature. This is why most plastics end up in landfills and are unable to be broken down. Plastics are an example of municipal solid waste, which is waste that is produced by homes and businesses.
In an ideal world, landfills would be eliminated because there would be no need for them anymore. If we could produce materials that were biodegradable, or at the very least recycle what was nonbiodegradable, we could eliminate problems like leachate. Leachate is a liquid that has passed through compact solid waste in a landfill. It comes from decomposing garbage. The severe problem with leachate is that it contains many chemicals. This can flow into groundwater and cause sickness. Another reason to produce more biodegradable materials is so that we can get rid of air pollution from the gasses emitted from the incinerators. Although incinerators are helpful in the sense that they are not taking up space on our planet, they can also emit dangerous chemicals into the air. If we could get rid of this then there would be clean air to breathe and fresher water to drink.
May 18, 2008 at 1:23 am
waste is any output with no use. the US produces 20 tons of carbon dioxide/person/year, or 6 million tons of carbon dioxide/year. we also produce more than 10 billion tons of solid waste every year. 85% of our waste ends up in landfills and only 15% is recycled.
the top three municipal waste categories are paper, food waste, and plastic. paper can easily be recycled into other paper products. composting is a common and efficient way of recycling food waste. compost piles turn food scraps, waste, and dirt into fertile soil that can be used instead of fertilizers with harmful chemicals. plastic can be recycled into clothing, flooring, benches, and other plastic products.