A two-stage deep dehydration method of municipal sludge chemical conditioning enhanced primary mechanical dehydration combined with electroosmosis

Abstract

The invention relates to a compound conditioner and a dehydration method for deep dewatering of municipal sludge. By adding a compound conditioner accounting for 3 to 30% of the dry weight of sludge, the water content of domestic sewage treatment plants is about 97%. Thickened sludge is conditioned and modified to improve the initial mechanical dehydration and subsequent electroosmotic dehydration capacity of the sludge; the moisture content of the conditioned modified sludge is reduced to 70-85% after preliminary dehydration; the preliminary dewatered sludge directly enters the electroosmotic dehydration The equipment performs deep dehydration, and the moisture content of the sludge is reduced to 40-60%. After dehydration, the sludge can be directly processed, disposed and resourced for landfill disposal, thermal conversion, and building material utilization. The method can realize the continuous operation of sludge dewatering, and has high treatment efficiency; can effectively reduce the bound water content in the sludge, has good dehydration effect, and has low moisture content of deeply dewatered cakes. It is not only suitable for newly-built sewage treatment plants, but also suitable for the reconstruction and expansion of sludge dehydration treatment in existing sewage treatment plants and the design requirements of emergency plans.

Description

technical field [0001] The invention relates to a new method of municipal sludge chemical conditioning strengthening preliminary mechanical dehydration-electric osmosis two-stage deep dehydration, which belongs to the technical field of urban sewage discharge sludge treatment and disposal, and is a new method for the treatment and disposal of excess sludge in urban sewage treatment plants. The process meets the requirements of sludge reduction, stabilization and harmlessness. Background technique [0002] The technology of my country's urban sewage treatment facilities is still dominated by biological methods, and a large amount of excess sludge will be produced in the process of wastewater treatment. According to relevant statistics of the "China Urban Drainage and Sewage Treatment Bulletin 2006-2010" issued by the Ministry of Housing and Urban-Rural Development, the total output of dewatered sludge (with a moisture content of 80%) in China in 2010 was close to 22 million t...

AI Technical Summary

Problems solved by technology

Although this process can meet the requirement that the moisture content of mechanically dewatered sludge is less than 80% in the "Pollutant Discharge Standards for Urban Sewage Treatment Plants" (GB18918-2002), it cannot meet the requirements of "Mixed Landfill Sludge for Urban Sewage Treatment Plant Sludge Disposal" (CJ / T249-2007) requires that the sludge mixed landfill moisture content is ≤60%

It also cannot meet the requirements of the document No. [2010] No. 157 of the General Office of the Ministry of Environmental Protection, "Where the sewage treatment plant transports the sludge to the factory for the purpose of storage (ie, no treatment and disposal), the sludge must be dehydrated to a moisture content of 50% the following"

[0007] The Chinese patent document "An Inorganic Composite Sludge Dehydration Conditioner and Its Application" (publication number CN101851053A) discloses a sludge dehydration conditioner and a conditioning method, specifically adding sludge accounting for 10-100% of the dry weight of the sludge Conditioning agent (sodium dodecylbenzene sulfonate and sodium hydroxide) conditions the sludge, and uses a plate and frame filter press to dehydrate the conditioned sludge, but only dewatered sludge with a moisture content of 70-75% can be obtained

At present, the dewatered sludge of the sewage treatment plant with a water content of 80% is mainly used as the research and experimental object for electroosmotic dehydration. Since the dewatered sludge of the sewage treatment plant is only added with a polymer flocculant to condition the sludge, there is no electroosmotic treatment. The dehydration process modifies the sludge, so the effect of electroosmotic deep dehydration directly on the dewatered sludge is not ideal

At the same time, in the relevant patented technology of sludge dewatering, there is basically no introduction of a new process that combines the electro-osmosis deep dewatering process with the original preliminary mechanical dewatering technology of the sewage plant, and there is no introduction to improve the initial mechanical dehydration of sludge and the follow-up Introduction of patents on electro-osmotic dehydration capacity sludge composite conditioning method and deep dehydration process

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