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Solid Waste. are useless, unwanted or hazardous materials resulting from human activities Rubbish that may decompose e.g. food materials Non-decomposable waste e.g. metal, glass. Solid Waste. solids from sewage treatment Ashes Large debris from construction works
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Solid Waste are useless, unwanted or hazardous materials resulting from human activities • Rubbish that may decompose e.g. food materials • Non-decomposable waste e.g. metal, glass
Solid Waste • solids from sewage treatment • Ashes • Large debris from construction works • Industrial waste e.g. chemicals • Farm waste e.g. manure, crop remains.
Ways of disposing solid waste • Composting • Decomposition of organic waste by micro-organisms • Process takes 3 weeks before the materials can be reused as fertilizers.
Ways of disposing solid waste • Recycling • Householders are asked to separate the waste • They are collected separately for recycling. • This reduces the volume of waste at incinerators / landfills
Ways of disposing solid waste • Landfill • Are used to bury waste. • At the landfill site the waste is spread in thin layers & bulldozed to compact the waste between each layer.
Ways of disposing solid waste • The site uses concrete linings to reduce pollution to ground water. • Once full, topsoil is added & the area is often landscaped for recreational use.
Ways of disposing solid waste • This is the most economic solution provided there are suitable sites available + they are close to the source of the waste • High cost involved in transporting waste to landfills
Ways of disposing solid waste • Incineration • The burning of waste materials • During combustion, carbon dioxide, sulphur oxides, nitrogen oxides, dioxins and ash are produced.
Ways of disposing solid waste • Modern installations use electrostatic precipitators, bag filters to remove any fine particles • Heat from the incineration process has been used for domestic heating
Ways of disposing solid waste • In recent years, fears of global warming and the release of harmful substances, dioxins, has made the siting of incinerators difficult.
Ways of disposing solid waste • New generation of ‘energy from waste’ (EfW) facilities are developed • They are cleaner than the old incinerators • They meet UK & EU environmental standards
Ways of disposing solid waste • Energy from waste facilities are an important source of renewable energy. This reduces the burden on burning fossil fuels.
Ways of disposing solid waste • The ash by-product can be recycled for use in the construction industry. Some will be placed in landfills. However it will reduce the landfill capacity needed.
Ways of disposing solid waste • Objections of EfW plant • Incineration is the source of serious toxic pollutants e.g. dioxins • Dioxins even at low level harm the environment & human health
Ways of disposing solid waste • Incineration always produce a toxic ash. This has to be disposed in landfills which is more likely to pollute water