Method for aerobic composting with urban sewage and sludge

Abstract

The invention provides a method for aerobic composting with urban sewage and sludge, which belongs to the technical field of solid waste treatment. The method comprises the following steps: mixing dewatered sludge and a backmixed compost product according to a weight ratio of 3:1 to 5:1, extruding the mixture to make sludge strips and parallelly placing a plurality of sludge strips on a light supporting plate to form a sludge layer; overlapping a plurality of layers of sludge and keeping interlayer spacing to form a sludge pile body and placing the pile body in a fermentation room; keeping ventilation for fermentation; and after fermentation, drawing the support plates out of the room to scrape the compost product from the supporting plates by baffle plates and collecting the compost product. The diameter of the cross section of the sludge strips is 1 to 1.5 centimeters and the spacing between the sludge strips is 0.5 centimeter. The interlayer spacing is 2 centimeters. The method avoids secondary fermentation and has high treatment efficiency and good weight reduction effect. Without any other residual dispersant, the compost product is good in processability and convenient to further produce a compound fertilizer, and can be burnt or used to make building materials. After being built, the pile can complete fermentation with proper ventilation rather than turning.

Description

Technical field [0001] The invention relates to an aerobic composting method of a de-cemented cake in an urban sewage treatment plant, and belongs to the technical field of solid waste treatment. Background technique [0002] Most of the urban domestic sewage in my country is treated by the activated sludge method, and a large amount of excess sludge is produced every year. With the increase in the discharge of urban domestic sewage and the increase in the treatment rate, the amount of sludge produced is increasing rapidly. A large amount of accumulated sludge not only occupies the land, but also contains a large number of organic nutrients and refractory organic matter, trace elements, pathogenic microorganisms and parasite eggs, heavy metals and other components in the sludge, which may pollute the ecological environment through different channels. Therefore, the sludge needs to be properly treated and disposed of. The main treatment and disposal methods of sludge include landf...

AI Technical Summary

Problems solved by technology

Dispersants generally use organic dispersants such as sawdust and straw, and the volume ratio of the added amount to the sludge is generally 1:1 to 2:1, so the volume of the pile is large and the sludge reduction effect is not good; on the other hand, due to These dispersants containing a large amount of lignin, cellulose and other refractory organic matter cannot be degraded in the first fermentation process. In order to ensure product performance, a second fermentation is required, making the entire treatment time as long as 1 to 3 months

[0004] Aiming at the problem of aerobic composting of sludge caused by the addition of dispersants, some researchers have proposed the method of adding recyclable dispersants, but they will still increase the volume of the pile, and after the composting is completed, it must be screened out to increase composting costs and processing steps

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