Method for producing hydrogen from residual sludge by anaerobic fermentation and microbial electrolysis cell coupling

Abstract

The invention discloses a method for producing hydrogen from residual sludge by anaerobic fermentation and microbial electrolysis cell coupling. The method comprises the following steps: S1, enriching anode electricity production bacteria by taking the residual sludge as an inoculums and using a double-chamber microbial fuel cell at the temperature of 20 to 25 DEG C, wherein when an external resistance voltage value of the microbial fuel cell tends to be stable and at least three cycles recur, enrichment of anode microorganisms is completed; S2, performing anaerobic fermentation on the residual sludge at the temperature of 35 DEG C under an oscillation condition for 7 days, to obtain residual sludge pretreated by medium-temperature anaerobic fermentation; S3, operating a single-chamber microbial electrolysis cell by taking the pretreated residual sludge as a substrate at the temperature of 20 to 25 DEG C under external voltage of 0.5 to 0.9 V, to produce hydrogen from the residual sludge. According to the method, products, such as volatile fatty acid, a carbohydrate and proteins, obtained by anaerobic fermentation of the residual sludge and a microbial electrolysis technology are used to produce hydrogen from small-molecule organic matters in fermentation supernate, so that reutilization of fermentation final products is realized.

Description

technical field [0001] The invention specifically relates to a method for coupling anaerobic fermentation and a microbial electrolytic cell to realize hydrogen production from surplus sludge. Background technique [0002] With the continuous development of my country's water environment protection work, the amount of sewage treatment is increasing day by day. The sewage treatment process based on biochemical technology will inevitably produce a large amount of excess sludge. The moisture content of these excess sludge is about 99%, including mud, sand, fibers, colloids, organic matter, microorganisms and metal elements. Harmful substances such as pathogens, organic pollutants and heavy metals pose a threat to the environment. It is estimated that by 2020, my country's sludge output will exceed 60 million tons, and the treatment and disposal of excess sludge has become a difficult problem for environmental protection. [0003] At present, my country's sludge treatment mainl...

AI Technical Summary

Problems solved by technology

However, traditional anaerobic digestion has "fermentation barriers", that is, organic matter is not completely fermented to produce gas

For example, the hydrogen production of glucose fermentation is 2-3mol / mol, which is far from the theoretical value of 12mol / mol. The reason is that the products of glucose fermentation, such as acetic acid, butyric acid and other small molecule volatile acids, cannot be used by fermentation bacteria.

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