Method for effective sterilization and efficient hydration of primary sludge

Abstract

The invention discloses a method for effective sterilization and efficient hydration of primary sludge, which comprises the following steps of: (1) primary sludge acidifying treatment for preparing slurry; (2) microwave heating sterilization: heating the slurry to between 30 and 90 DEG C; (3) mechanical filtration: performing solid-liquid separation on the microwave heated slurry, and washing the solid by using water to obtain dry sludge residue and new slurry; and (4) adjusting pH value of the new slurry to be between 6.0 and 8.5 by using lime, wherein the new slurry can be used as circulating water for sludge acidification for preparing the slurry and separation and washing of the mechanical filtration, and the rest recycled partial new slurry can be returned to a sewage treatment system of a sewage treatment plant. The method realizes direct effective sterilization and efficient hydration of the primary sludge generated by the sewage treatment plant without the processes of secondary deposition, concentration, digestion and the like, and can save a large amount of operating cost.

Description

technical field [0001] The invention relates to a method for dehydrating and effectively sterilizing primary sludge in a sewage treatment plant, in particular to a method for effectively sterilizing and efficiently dehydrating primary sludge. Background technique [0002] At present, while my country's sewage treatment capacity continues to grow, so does the sludge generated from urban sewage treatment. Most of the original sludge has not been properly disposed of, and the phenomenon of random discarding and dumping is still common. The secondary pollution caused by this cannot be ignored. To a certain extent, it even offsets the achievements of pollution reduction. In some areas Also due to improper disposal of sludge, caused environmental pollution incidents. [0003] Sludge is a solid-liquid mixture produced in each unit of the sewage treatment system. It is an accessory product of the sewage treatment process. Its basic characteristics are as follows: [0004] 1) In ad...

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Problems solved by technology

[0005] 2) The moisture content of the sludge is high, the moisture content of the primary sludge reaches 97-99.5%, and after the concentration treatment, the water content still reaches 80-85%. potential pollution

[0006] 3) The compounds contained in the sludge itself produce gas to form a peculiar smell, and under the action of microorganisms, a large amount of stench is produced, which is difficult to remove

However, through practical application, it has been found that these processes require large investment, occupy a large area, consume large amounts of energy, and have high operating costs. They need to add a large number of flocculation (coagulant) agents and bring difficulties to subsequent processes, and there is still a great difficulty in dehydration.

Under the current technical conditions, sterilization is generally carried out in the activated sludge generated during the digestion process, and sterilization is not carried out in the initial stage (primary sludge)

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