A device and method for strong alkali pretreatment to strengthen the production of acetic acid by alkaline fermentation of excess sludge

Abstract

The invention relates to an apparatus and a method for producing acetic acid through alkaline fermentation of residual sludge which is reinforced by pretreatment of strong base, which belongs to the technical field of acid production through anaerobic fermentation of sludge. The apparatus comprises a residual sludge case, a SBR apparatus, a sludge pump, a sludge inlet pump, an agent pump, a pH determinator, a sludge discharge case, a stirrer, a feeding case, and a heating rod. The method comprises the following steps: under temperature between 25+ / -1 DEG C, performing pretreatment on residual sludge after elutriation in a strong base (pH is 12) SBR apparatus, pumping into a semi-continuous flow fermentation SBR apparatus for alkalescence (pH is 12) anaerobic fermentation, controlling SRT of the semi-continuous flow fermentation SBR apparatus for 10 days, and increasing acetic acid content in the semi-continuous flow fermentation SBR apparatus.

Description

Technical field: [0001] The invention relates to a device and method for strong alkali pretreatment to strengthen residual sludge alkaline fermentation to produce acetic acid, belonging to the technical field of sludge anaerobic fermentation acid production. The remaining sludge is pretreated with strong alkali (pH=12) and then subjected to alkaline (pH=10) fermentation to increase the production of acetic acid. Background technique: [0002] At present, there are generally problems of insufficient carbon sources and low C / N in urban domestic sewage in our country. In order to improve the effluent quality of sewage treatment plants, it is necessary to add a large amount of external carbon sources (such as methanol, sodium acetate, etc.) to the sewage. Strengthen the ability of microorganisms to remove nitrogen and phosphorus, but the addition of external carbon sources will greatly increase the treatment cost of sewage treatment plants. At present, urban sewage treatment pl...

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Problems solved by technology

[0005] Aiming at the problem that the amount of acetic acid produced by fermentation of excess sludge under alkaline conditions is low, the present invention proposes a device and method for strong alkali pretreatment to strengthen the production of acetic acid by alkaline fermentation of excess sludge

With the help of two sequenced batch activated sludge reactor (SBR) devices, this method changes the traditional method of adding alkali to control a single pH value (pH=10) to increase the acid production of sludge fermentation, but first treats the remaining sludge Alkaline fermentation (pH=10) is carried out after strong alkali (pH=12) pretreatment, which solves the problems of low acetic acid production in alkaline fermentation of excess sludge and the treatment and disposal of excess sludge

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