Method for promoting anaerobic fermentation of municipal excess sludge to produce volatile fatty acids

A technology of volatile fatty acids and excess sludge, which is applied in the field of solid waste recycling, can solve the problems of increased sludge treatment costs and high costs, and achieve the effects of resource utilization, consumption reduction, and volume reduction

Pending Publication Date: 2020-09-25
MOUTAI INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The traditional alkali treatment mainly uses high-cost soda ash, such as sodium hydroxide, calcium hydroxide, etc. During the large-scale anaerobic fermentation of sludge, the addition of soda ash increases the cost of sludge treatment

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] Use a 250ml serum bottle as a fermentation bottle, add urban surplus sludge and inoculation sludge at a ratio of VSS 1:1, do not add any amount of carbide slag, first fill the fermentation bottle with nitrogen for 5 minutes, and place the fermentation bottle in an air bath at constant temperature Oscillator, the temperature is controlled at 35±1°C, the stirring speed is 120r / min, and the VFAs content is measured by regular sampling. The number of fermentation days is 10 days. The content of VFAs in the liquid. The results showed that the production of VFAs in the sludge fermentation process could reach 39.33mg COD / g VSS at most.

Embodiment 2

[0022] Use a 250ml serum bottle as a fermentation bottle, add urban surplus sludge and inoculation sludge at a ratio of VSS 1:1, add a certain amount of carbide slag to make the pH of the fermentation system 8, first fill the fermentation bottle with nitrogen for 5 minutes, and ferment The bottle is placed in an air bath constant temperature oscillator, the temperature is controlled at 35±1°C, the stirring speed is 120r / min, and the VFAs content is measured by regular sampling. The number of fermentation days is 10d. After centrifugal filtration, the content of VFAs in the supernatant was determined. The results show that the output of VFAs can reach 66.07mg COD / g VSS at most, which is 1.68 times higher than the highest VFAs output in Example 1.

Embodiment 3

[0024]Use a 250ml serum bottle as a fermentation bottle, add urban surplus sludge and inoculation sludge at a ratio of VSS 1:1, add a certain amount of carbide slag to make the pH of the fermentation system 9, first fill the fermentation bottle with nitrogen for 5 minutes, and ferment The bottle is placed in an air bath constant temperature oscillator, the temperature is controlled at 35±1°C, the stirring speed is 120r / min, and the VFAs content is measured by regular sampling. The number of fermentation days is 10d. After centrifugal filtration, the content of VFAs in the supernatant was determined. The results show that the output of VFAs can reach 186.49mg COD / g VSS at most, which is 4.74 times higher than the highest VFAs output in Example 1.

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PUM

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Abstract

The invention discloses a method for promoting anaerobic fermentation of municipal excess sludge to produce volatile fatty acids. The method comprises the following steps: (1) concentrating municipalexcess sludge taken back from a sewage plant, then mixing inoculated sludge with the municipal excess sludge, putting a mixture into six fermentation bottles, and respectively adding different amountsof carbide slag into the fermentation bottles so as to adjust the alkaline condition of a fermentation system; (2) introducing nitrogen into the fermentation bottles to keep the fermentation bottlesin an anaerobic environment, sealing the fermentation bottles, adding the carbide slag every 24 hours to adjust the pH value of the fermentation bottles to a required alkaline condition, and carryingout alkaline fermentation; and (3) mixing fermented liquids in the step (2) by adopting a high-speed centrifuge, and performing centrifuging at a centrifugal speed of 10,000 r / min and a centrifugal temperature of 4 DEG C to obtain supernatant, namely municipal excess fermentation liquor containing the VFAs. With the method, the sludge fermentation cost can be reduced, the produced volatile fatty acids have a wide application prospect, and the purpose of treating waste with waste is achieved.

Description

technical field [0001] The invention relates to a method for promoting anaerobic fermentation of surplus urban sludge to produce volatile fatty acids, and belongs to the technical field of solid waste recycling. Background technique [0002] Urban surplus sludge is the main by-product of sewage treatment plants, among which the management and disposal costs of sludge account for more than 1 / 3 of the total infrastructure costs and operating costs of sewage plants. With the improvement of human society and people's living standards, sewage treatment The amount of sludge produced by the plant is increasing. Traditional sludge disposal technologies mainly include incineration and landfill. Sludge contains a large amount of organic matter (mainly including protein and polysaccharides, etc.). Due to the demand for sustainable development, the treatment of sludge has begun to change to resource utilization, and the production of bioenergy and high-value chemical products through ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C12P7/52C12P7/54
CPCC12P7/52C12P7/54
Inventor 陶雪熊小燕
Owner MOUTAI INST
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