A method for pre-fermentation and enhanced anaerobic digestion of excess sludge to produce methane

A technology of excess sludge and anaerobic digestion, applied in the field of environmental engineering, can solve the problems of slow acidification rate and low methane production efficiency, and achieve the effects of simple method, shortened digestion residence time and low investment cost.

Active Publication Date: 2020-12-18
SHANGHAI JIAO TONG UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Aiming at the technical problems of slow anaerobic digestion, hydrolysis and acidification rate of excess sludge and low methane production efficiency, the present invention provides a method of using glycine chelated nickel to pre-fermentation acid production to strengthen sludge anaerobic digestion to produce methane

Method used

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  • A method for pre-fermentation and enhanced anaerobic digestion of excess sludge to produce methane
  • A method for pre-fermentation and enhanced anaerobic digestion of excess sludge to produce methane

Examples

Experimental program
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Effect test

Embodiment 1

[0039] Concentrate the remaining sludge from the sewage plant to adjust the solid content to 20g / L, mix it with the digested sludge in the anaerobic digestion tank with a solid content of 50g / L at a volume ratio of 1:8, adjust the initial pH of the fermentation mixture to 5, and adjust the fermentation mixture per Kg 10mg of glycine chelated nickel was mixed, mixed evenly, and then fermented in a hydrolysis fermentation tank for 5 days. During the process, the pH was controlled at about 5, and the temperature was set at 33°C; after the pre-fermentation, the fermentation mixture was introduced into the adjustment tank, and the pH was adjusted to 7 and then introduced into the methanation tank, the final cumulative methane production was 264mL / g·VS.

Embodiment 2

[0041] Concentrate the remaining sludge from the sewage plant and adjust the solid content to 30g / L, mix it with the digested sludge in the anaerobic digestion tank with a solid content of 50g / L at a volume ratio of 1:8, adjust the initial pH of the fermentation mixture to 6, and adjust the fermentation mixture per Kg 20mg of glycine chelated nickel was mixed in proportion, mixed evenly and then fermented in a hydrolysis fermenter for 1 day. During the process, the pH was controlled at about 6, and the temperature was set at 35°C; 7 and then introduced into the methane tank, the final cumulative methane production was 245mL / g·VS.

Embodiment 3

[0043] Concentrate the remaining sludge from the sewage plant to adjust the solid content to 40g / L, mix it with the digested sludge in the anaerobic digestion tank with a solid content of 50g / L at a volume ratio of 1:8, adjust the initial pH of the fermentation mixture to 5.5, and adjust the fermentation mixture per Kg 30mg of glycine chelated nickel was mixed, mixed evenly, and then fermented in a hydrolysis fermentation tank for 3 days. During the process, the pH was controlled at about 5.5, and the temperature was set at 37°C; after the pre-fermentation, the fermentation mixture was introduced into the adjustment tank, and the pH was adjusted to 7 and then introduced into the methanation tank, the final cumulative methane production was 293mL / g·VS.

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Abstract

The invention provides a method for producing methane through pre-fermenting and strengthening surplus sludge anaerobic digestion. The method comprises the following steps of S1, precipitating and concentrating a sludge to obtain a sludge to be treated; S2, mixing an inoculating mud and the sludge to be treated obtained in the step S1 according to the proportion so as to obtain a fermented mixture, and adjusting pH of the fermented mixture to be acid; S3, mixing the fermented mixture obtained in the step S2 and chelate nickel glycinate according to the proportion, and carrying out hydrolysis fermentation. By using the chelate nickel glycinate under a weak acid condition, the relative abundance of acidogenic fermentation bacterium Clostridia can be improved, the sludge hydrolytic acidification speed is accelerated, and an acidogenic fermentation type is optimized for providing a beneficial substrate for methanogens; meanwhile, through a nickel element dissolved in the sludge, the relative abundance of the methanogens Methanosaeta can be also improved, and the performance for producing the methane through sludge anaerobic digestion is effectively improved.

Description

technical field [0001] The invention belongs to the technical field of environmental engineering, and relates to a method for pre-fermenting and strengthening anaerobic digestion of excess sludge to produce methane, and more specifically, to a method for using glycine chelated nickel to pre-ferment and produce acid to strengthen sludge anaerobic digestion for producing methane method. Background technique [0002] In recent years, the scale of urban sewage treatment in my country has continued to expand, manifested in the increase of new sewage treatment facilities and the renovation and expansion of existing sewage treatment facilities; as of September 2016, a total of 3,976 urban sewage treatment plants have been built nationwide, with a treatment capacity of 170 million cubic meters per day, and according to the overall evaluation report of China's sewage treatment market, the scale of urban sewage treatment will still have a large increase in the next ten years. The incr...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C02F11/04
CPCC02F11/04
Inventor 朱南文于豹袁海平楼紫阳沈雁文尹常凯
Owner SHANGHAI JIAO TONG UNIV
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