Analysis of advantages and disadvantages of several sludge treatment methods
① sanitary landfill of sludge
This disposal method is simple, easy to operate, low cost, sludge does not need high dehydration, strong adaptability. But there are also some problems in sludge landfill, especially the formation of landfill leachate and gas. Leachate is a kind of seriously polluted liquid. If the landfill site is located or operated improperly, it will pollute the groundwater environment. The gas produced in landfill is mainly methane, which will cause explosion and combustion if proper measures are not taken.
② direct land use of silt
Because of the advantages of less investment, low energy consumption, low operating cost, and organic parts can be converted into soil improver components, sludge land direct use is considered to be the most potential disposal method. Scientific and reasonable land use can reduce the negative effects of sludge. The utilization of forest land and municipal greening is an effective way to utilize silt land because it is not easy to cause food chain pollution. Sludge is used for the restoration and reconstruction of seriously disturbed land (such as mine land, forest cutting field, landfill, surface seriously damaged area, etc.) to reduce the potential threat of sludge to human life, which not only disposes the sludge but also restores the ecological environment.
③ incineration of sludge
Direct incineration after drying of wet sludge is widely used. Direct incineration of sludge without drying is not only very difficult, but also uneconomical in energy consumption. The sludge treatment method with incineration as the core is the most thorough sludge treatment method, which can carbonize all organic matters, kill pathogens, and minimize sludge volume; however, its disadvantages lie in large investment in treatment facilities and high treatment costs.