Method for treating residual active sludge by combined process of bipolar membrane electrodialysis for acid and alkali production, thermal hydrolysis and anaerobic digestion

Abstract

The invention discloses a method for treating residual active sludge by a combined process of bipolar membrane electrodialysis for acid and alkali production, thermal hydrolysis and anaerobic digestion. The method comprises the following steps: S1, with salt as a raw material, producing acid and alkali with an equal molar concentration by utilizing a bipolar membrane electrodialysis device; S2, pouring the alkali obtained in the step S1 into remaining active sludge, carrying out uniform mixing, carrying out alkali pretreatment, and jointly carrying out thermal pretreatment, wherein the temperature of thermal pretreatment is 100 to 190 DEG C, and the time of thermal pretreatment is 20 to 100 min; and S3, uniformly mixing a product obtained in the step S2 with the acid obtained in the step S1, and carrying out anaerobic digestion treatment. According to the invention, through the process of pretreatment, the release and hydrolysis process of organic matters in the process of anaerobic fermentation can be promoted, and high-efficiency pretreatment to the remaining active sludge can be realized, so the digestion efficiency of the remaining active sludge is improved, and the removal rate of carbon is increased; meanwhile, the treatment method provided by the invention has low acid and alkali production cost, simple operation, no increase of the pretreatment operation difficulty of the remaining active sludge, strong applicability and easy popularization and application.

Description

technical field [0001] The invention relates to the technical field of anaerobic treatment of sludge, and more specifically relates to a method for treating excess activated sludge through the combined process of bipolar membrane electrodialysis acid-base generation-thermal hydrolysis-anaerobic digestion. Background technique [0002] In the research of sewage treatment, the treatment and disposal of excess activated sludge is a big problem. It is predicted that the surplus sludge output in my country will reach 83.82 million tons in 2020. The remaining activated sludge contains a large amount of organic matter and rich nutrients such as nitrogen and phosphorus. It also contains factors that are likely to endanger human health such as pathogenic bacteria and parasite eggs. If it is not stabilized and discharged arbitrarily, it will cause serious environmental pollution. question. Therefore, the remaining activated sludge must be treated and disposed of to achieve the purpo...

AI Technical Summary

Problems solved by technology

However, in this process, due to the protection and encapsulation of protoplasts by the extracellular polymers on the surface of sludge flocs and microbial cell membranes and cell walls, it is difficult for the hydrolytic enzymes secreted by microorganisms to effectively enter the cytoplasm to complete the hydrolysis process, thus limiting The effect of sludge anaerobic digestion

As a result, the digestion efficiency of the remaining sludge is low, and the carbon removal rate needs to be improved

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