Agenda - Council - 08/14/1984 - Laserfiche WebLink

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I I I I I I I I I I I I I I I I I Page Six Mechanical separation methods capable of separating solid waste into valuable components have been developed based upon techniques in the mining industry. Although still somewhat experimental there are two basic approaches to mechanical separatiom wet processing and dry processing. Both approaches utilize a series of processes that begin with volume reduction using a shredder followed by air-classification of the waste stream into light and heavy components and final processing to recover marketable materials using magnetic separators and other equipment. Mechanical separation may preceed incineration in waste to energy facilities. Magnetic aluminum separators are currently being used at large scale recycling centers and scrap metals processors. In general, only ferrous and aluminum metal recovery is, at the current time, technically and economically feasible using mechanical separation technol~ (See Appendix II! for costs). Shredding is a solid'waste volume reduction technique that consists of milling the waste to reduce waste constituents to smaller more uniformly sized particles thus reducing the amount of void space between waste particles. Shredding operations normal ly consist of a shredding unit, a transport network, and a shredfiil (a landfill accepting shredded wastes). The shredding process can result in up to 30% volume reduction at the landfill site. Doily cover may not be required since litter, fire, and other nuisance problems are reduced or eliminated because of the more homogeneous and homogenized nature of the waste. Decreased settlement and improved operation during cold or wet weather have also been noticed at shredfills. Shredded waste will facilitate landfill stabilization and reduce the time period required for monitoring (See Appendix II! for costs). Baling is a solid waste abatement technique that consists of compacting the raw solid waste into high density (approximal~ely 1,800 lbs. per cubic yard) rectangular bales. A baling operation normally will consist of a baling unit, transport network, and balefiil (landfill accepting baled waste). The basic advantages of baling are reduction in required landfill volume (approximately ~ - 60% reduction), ease of transportation, ease of placements litter reduction, decreased settlement, and reduced requirements for cover material. Because of the density of the bale, the decomposition process is greatly retarded thus potentially extending the period of time during which the landfill will continue to generate gas and leachate. This will necessitate an extended period of environmental monitoring to ensure that adverse effects do not develop.