Method for promoting residual sludge to carry out anaerobic fermentation to produce acid

A technology for anaerobic fermentation of sludge and excess sludge, applied in fermentation and other directions, can solve the problems of high equipment requirements and large energy consumption of ultrasonic pretreatment methods, so as to save operating costs, shorten sludge fermentation time, and promote dissolution. Effect

Inactive Publication Date: 2015-03-11
NANJING UNIV OF SCI & TECH
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the ultrasonic pretreatment method consumes a lot of

Method used

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  • Method for promoting residual sludge to carry out anaerobic fermentation to produce acid
  • Method for promoting residual sludge to carry out anaerobic fermentation to produce acid

Examples

Experimental program
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Effect test

Embodiment 1

[0027] Take 250mL of excess sludge (water content 97%, pH=6.87) and put it into an anaerobic reactor for fermentation to produce acid. The dosage of nitrite in the pretreatment guarantees NO 2 - =0.05g / g DS, pretreatment time is 24h, pH is 5.0. Nitrogen and deoxygenation were performed for 10 minutes during the alkaline digestion process, the pH value was adjusted to 9.0, the reaction temperature was 30±1°C, the residence time in the reactor was 3 days, and the short-chain fatty acid produced was 873 mg per liter.

Embodiment 2

[0029] Take 250mL of excess sludge (water content 97%, pH=6.87) and put it into an anaerobic reactor for fermentation to produce acid. The dosage of nitrite in the pretreatment guarantees NO 2 - =0.1g / g DS, pretreatment time is 24h, pH is 5.0. Nitrogen and deoxygenation were carried out for 10 minutes during the alkaline digestion process, the pH value was adjusted to 9.0, the reaction temperature was 30±1°C, the residence time in the reactor was 3 days, and the short-chain fatty acid produced was 1045 mg per liter.

Embodiment 3

[0031] Take 250mL of excess sludge (water content 97%, pH=6.87) and put it into an anaerobic reactor for fermentation to produce acid. The dosage of nitrite in the pretreatment guarantees NO 2 - =0.2g / g DS, pretreatment time is 24h, pH is 5.0. Nitrogen and deoxygenation were carried out for 10 minutes during the alkaline digestion process, the pH value was adjusted to 9.0, the reaction temperature was 30±1°C, the residence time in the reactor was 3 days, and the short-chain fatty acid produced was 781 mg per liter.

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Abstract

The invention discloses a method for promoting residual sludge to carry out anaerobic fermentation to produce acid, and belongs to the technical field of solid waste processing and recycling. The provided method aims to solve the problems of low hydrolysis speed and insufficient short-chain aliphatic acid accumulation during the sludge anaerobic digestion process. The sludge is subjected to a nitrite pretreatment to increase the dissolution of organic matters, then the pH value is adjusted to an alkaline area to further promote the organic matter hydrolysis and short-chain aliphatic acid accumulation during the sludge anaerobic fermentation process, and at the same time the activity of microorganisms, which can produce methane, is prohibited, so the yield of short-chain aliphatic acid is increased. The provided method can effectively shorten the retention time of sludge anaerobic fermentation, increase the acid producing efficiency, and achieve the goals of sludge reduction and recycling.

Description

technical field [0001] The invention belongs to the technical field of environmental protection and solid waste recycling, and in particular relates to a method for using nitrite pretreatment coupled with alkaline digestion to promote anaerobic fermentation of sludge to produce short-chain fatty acids. Background technique [0002] As the activated sludge method is widely used in urban and industrial wastewater treatment processes, more and more scholars have paid more and more attention to the treatment and disposal of the excess sludge generated, and how to reduce and recycle the excess sludge has become a research hotspot. Sludge is mainly composed of microbial groups and a large amount of organic matter attached to it, accounting for about 60%, and more than 40% of biodegradable organic components, which are rich sources of nutrients for microorganisms. Effective use of its potential carbon source has become the key to the study of excess sludge pollution control and re...

Claims

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Application Information

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IPC IPC(8): C12P7/40
CPCC12P7/6409
Inventor 孙秀云黄诚王连军刘聪聪沈锦优李健生刘晓东韩卫清孙颖璐李瑞
Owner NANJING UNIV OF SCI & TECH
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