The Research For Sludge Harmless Treatment Technologies Integration In The Cold-dry Area

The sludge of sewage treatment plant production increased rapidly withpopularizing and running in cold-dry area sewage treatment plant. How to solve theproblem of sludge treatment has become a major environmental problem to besolved in this area. This article takes the harmless sludge treatment technologies ofcold-dry area for the research object, takes the whole cold-dry area and the sludge ofsewage treatment plant for the clue, mainly focusing on the key technical and the costof sludge drying, sludge earthworm composting, high temperature sludgecomposting, renewable fuels, forming the four suitable sets technology unit forurban sludge treatment in this area, and forming system integration by optimization,integration. And then provide technical support for the sludge treatment and itsindustrialization development.The two main contents of this article are as follows:1. Combing the abroad historical process and progress status of sludge harmlesstreatment and taking the time as a clue from a macro view point. While analyzed thecold-dry area sludge treatment from natural environment and the economicbackground in this area.2. Analyzing and summarizing sludge treatment technology through theformation and characteristics of sludge from a microscopic view point:（1）Sludge drying is a relatively expensive sludge treatment technology，because the larger the cost of investment, and relatively high operation cost. If usingsludge natural drying technology, Not only can take full advantage of local climaticresources but also can save energy, reduce operating costs, and in fact is the first stepof the sludge subsequent treatment and resource utilization.（2）The cold-dry area can take the sludge for sludge earthworm compostingafter sludge natural drying technology. This technology not only has the advantagesof simple process, low cost, and also can effectively decompose the organic matters inthe sludge conversion, removal of pathogenic microorganisms, enrichment of theheavy metals, laying a further foundation for the high temperature sludge compost.（3）As the earthworm composting is good for removal of heavy metals, and theheavy metals is one of the limited factors of products agricultural effect for the hightemperature sludge composting. Therefore, earthworm composting sludge compostingcan reach the final sludge agricultural purposes if used the high-temperature sludgecomposting as the preprocessing. When cold-dry area using high temperature sludge composting needs to be considered the technical points of the influence ofwinter indoor and outdoor temperature effects on the temperature and oxygen of theheap. And it has the utility of improving soil, increasing land fertilizer, promotingplant growth and increasing production after the high temperature sludge composting,it also be good for sustainable development of agriculture.（4）Renewable fuels as the last step of this integration system, is forthefinalstage of sludge resource utilization, The Sludge calorific value is equivalentto the25%~50%of the bituminous coal after drying treatment and is also suitable forincineration. Renewable fuels can not only eliminate the sludge on the environmentpollution, but also save a lot of coal resources, and greatly reduce the emissions ofatmospheric pollutants.This article studies the four harmless sludge treatment technologies through theunderstanding of the cold-dry area and the sludge. Deepening and summarizing theoptimization and integration of the technology system after the further analysis oftechnology. Provide a reference to management and decision-making of sludgetreatment and sewage treatment plant sludge treatment departments in cold-dry areas.