Method for treating low-heating value excess sludge

Abstract

The invention provides a method for treating low-heating value excess sludge, which comprises the following steps of: storing calcined lime in a calcined lime storage bin, and conveying different amounts of calcined lime in an amount which is 20 to 50 percent of the mass of the excess sludge into a mixed reactor by using a reactant metering device according to requirements; conveying excess sludge to be treated with the moisture content of between 80 and 90 percent and the calcined lime into the mixed reactor, and mixing uniformly for reaction to prepare half-dried sludge; and feeding the half-dried sludge into a sludge granulating device, crushing to form sludge granules, guiding the granules into a solar drying room, drying for 24 to 48 hours to obtain dried sludge with the moisture content of between 5 and 10 percent, and introducing generated stench into a waste gas treatment device. The method has the advantages that: the aims of the innocuity and minimization of the excess sludge are fulfilled by lower energy consumption without generation of secondary pollution; and compared with that of a mode of treating the excess sludge by using the calcined lime merely, the using amount of the calcined lime can be reduced by the method.

Description

technical field [0001] The invention relates to the field of excess sludge treatment and disposal, in particular to the disposal method of excess sludge with lower calorific value. Background technique [0002] Residual sludge is the solid sediment produced in the process of sewage treatment, which contains a large amount of water, inorganic ash and organic volatiles. With the development of social economy and urbanization in our country, the generation and quantity of urban sewage are constantly increasing. At present, there are more than 500 urban sewage treatment plants in operation across the country, with an annual treatment capacity of 11.36 billion m 3 . According to relevant predictions, the amount of urban sewage in my country will increase significantly in the next two decades, and the amount of sewage discharged by the end of 2010 will reach 440×10 8 m 3 / d; In 2020, the sewage discharge will reach 536×10 8 m 3 / d. The improvement of sewage treatment effi...

AI Technical Summary

Problems solved by technology

If the remaining sludge is not properly treated and disposed of, it will not only occupy a large amount of land, but also cause secondary pollution to the environment and become a major public hazard affecting urban environmental sanitation.

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