Back mixing method for pretreatment of sludge

Abstract

A back mixing method in the biological pretreatment of sludge comprises the steps: a) the dry sludge plastotype with the water ratio being 35 percent to 37 percent is processed into cylindrical granular dry sludge A and striping dry sludge B, which are dried until the water ratio reduces to 20-25 percent; b) the dry sludge A and B prepared in step a are mixed as per the mass ratio of 8-10:1 to bemade into back mixing dry sludge; c) the back mixing dry sludge is mixed with wet sludge and accounts for 25-35 percent of the mass of the total materials, and the turn and throw are carried out for 3-7 times per week, with ventilation and oxygen supply, the temperature is maintained between 45-60 DEG C, when the water ratio reaches 35 percent to 37 percent, fertilizer manufacture and incineration and other subsequent disposals are conducted. Through the back mixing of the dry sludge A and B of different shapes, the invention can reach the aims of improving the space structure of sludge and shortening the pretreatment period; and the final pretreatment product dry sludge is of granular structure, which is more beneficial to the execution of further disposals such as fertilizer manufactureand incineration.

Description

technical field [0001] The invention relates to the field of environmental protection and belongs to the category of sludge treatment, in particular to a back-mixing method in sludge biological pretreatment technology. Background technique [0002] Since the establishment of the first sewage treatment plant in London, England in 1857, the world's sewage treatment industry has developed rapidly, and the rate of urban sewage treatment has increased year by year, and the amount of sludge produced has become larger and larger. The problem of its treatment and disposal has become a global city. It is a major problem faced by municipal management, if it is not properly handled, it will bring about great environmental pollution problems. [0003] The principles of sludge treatment and disposal are reduction, harmlessness, stabilization, and recycling. At present, more mature processes generally use landfill, incineration, and agricultural use. However, no matter what method is used...

AI Technical Summary

Problems solved by technology

At present, most of the additives used in actual production are sawdust, straw, etc. The amount of such additives is large, the cost is high, the source is limited by region and season, and the main components are mostly lignin and cellulose, which will prolong the processing cycle and directly add Large processing costs, bring a lot of inconvenience to production

Images