Solid Waste Management and Disposal固体废物管理和处置.ppt

Solid Waste Management and Disposal Outline Waste Disposal Methods Landfills, Incineration, Composting Source Reduction 源头削减 Recycling Problems and Concerns Regulating hazardous materials Hazardous vs. Toxic Setting Regulations Associated Health Risks EPA’s Management Strategy Municipal Solid Waste In modern society, many products are discarded when they are broken or worn out, while others only have a temporary use. Those that have only temporary uses make up the majority of solid waste. Lack of dumping 堆放 space has become a problem for many large metropolitan 大都市 areas. Why? Population increase Convenience lifestyle Communities are increasingly concerned about waste disposal costs, and groundwater (landfill) and air quality hazards (burning). Disposable Decades In the mid 1950’s a disposable 用后即弃 lifestyle was marketed as the wave of the future, and as a way to reduce household duties. Consumerism began in earnest following WWII. Convenience was sold to prosperous post-war consumers. “Convenience” was quickly changed to necessity. Nature of the Problem Garbage = Municipal Solid Waste US produces 220 million metric tons of municipal waste per year, 2kg/p.d. US volume has doubled since 1960. Municipal Solid Waste Generation Rates CHN produces 108 million metric tons in 1996, 0.3kg/p.d, 0.8-2.0kg/p.d in cities. CHN volume increased 8-10% per year recently, will double in 7 years. MDCs have a higher standard of living, and thus produce more waste. Waste Generation and Lifestyle Waste Disposal Methods Traditional Methods (dumping and burning) are no longer accepted. Essentially, four techniques are used: Landfills Incineration Composting Recycling Fig. 18.7 Methods of Waste Disposal Landfills Landfilling has traditionally been the primary method of waste disposal - cheap and convenient. Traditional - A simple hole in the ground to dump garbage Groundwater contamination Modern landfills have complex impermeable bottom layers to trap contaminants, and daily deposit