Method for improving acid production quality and acetic acid proportion in anaerobic fermentation of residue active sludge

Abstract

The invention relates to a method for improving acid production quality and acetic acid proportion in anaerobic fermentation of residue active sludge. The method comprises the following steps of firstly, adding calcium peroxide into concentrated residual sludge in a wastewater treatment plant, wherein adding amount of the calcium peroxide is 5%-20% of the weight of the volatile suspended solid in the residual active sludge; then, sealing at 30-40 DEG C, carrying out anaerobic digestion in an anaerobic digestion tank with stirring speed of 100-200rpm, wherein the anaerobic digestion time is 5-10 days. The result indicates that calcium peroxide can promote dissolution of particulate organic substances, can improve acidification degree of deliquescent organic substances and can inhibit a methane production process, so that accumulation of volatile short-chain fatty acid is facilitated and transformation of other acids to acetic acid is promoted; meanwhile, a plurality of harmful organic substances in the sludge are effectively removed, so that the acid production quality in anaerobic fermentation of the residue active sludge is improved. The method disclosed by the invention is simple to operate and gentle in reaction condition, is used for recycling and carrying out harmless disposal on the concentrated residual sludge of the sewage treatment plant, and has very good economic and social benefits.

Description

technical field [0001] The invention relates to a method for improving the quality of acid produced by anaerobic fermentation of excess activated sludge and the ratio of acetic acid. The invention belongs to the technical field of sludge treatment and resource utilization. Background technique [0002] At present, the most widely used activated sludge treatment technology in the world produces a large amount of sludge (including primary sludge and residual activated sludge). The high cost of treatment and disposal of excess activated sludge is one of the major challenges for wastewater treatment plants. The content of organic matter in excess activated sludge is high. If some of the usable substances can be recovered, it will save costs and achieve the purpose of sludge reduction and resource utilization. At present, the most widely used residual activated sludge treatment method is anaerobic fermentation. The intermediate products of the anaerobic fermentation process ar...

AI Technical Summary

Problems solved by technology

The above patented technologies only focus on the acid production by anaerobic fermentation of sludge and ignore the refractory harmful organic substances in the sludge fermentation liquid. Many studies have shown that in the process of sewage treatment, sludge will absorb a large number of organic pollutants, such as: surface activity agents, personal care products, drugs, estrogen, etc., but simple anaerobic fermentation or alkaline, thermal fermentation, etc. are difficult to remove refractory organic pollutants on the surface of sludge solid particles and in the fermentation liquid, so the fermentation liquid is used as a carbon source recovery It still contains a large amount of organic pollutants when utilized, which reduces the quality of the fermentation broth

In addition, the above patented technologies only focus on the total acid production in the sludge anaerobic fermentation broth, and do not pay attention to the components of the acid, especially the content of acetic acid

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