Combined pre-treatment method for improving sludge disintegration effect and strengthening subsequent anaerobic digestion

An anaerobic digestion and pretreatment technology, applied in chemical instruments and methods, sludge treatment, biological sludge treatment, etc., can solve problems such as poor hydrolysis of solid debris

Inactive Publication Date: 2009-10-28
TONGJI UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Through comparative research, it is found that ultrasonic cracking technology has the advantages of no pollution, high energy density, fast decomposition speed, etc., and has the adv

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] The properties of the residual sludge of Quyang sewage treatment plant in a certain place after gravity settlement are shown in the table below.

[0019]

[0020] Use 20kHz, 2.0w / ml ultrasonic treatment for 20 minutes, and the dosage of NaOH is 0.03g / gTS. Put it in a shaker at 25±2°C for 24 hours, then take 200ml of combined pretreatment sludge and send it to an anaerobic digestion reactor, and put it in a shaker at 35±2°C for mesophilic anaerobic digestion. The soluble COD in the treated sludge increased to 6963.250mg / L, which was about 44 times higher than that of the untreated sludge. After 14 days of anaerobic digestion of sludge pretreated by ultrasonic and NaOH, the amount of methane produced was basically the same as that of untreated sludge after 22 days of anaerobic digestion. However, when the two sludges were digested for 22 days, the amount of methane produced was 298.7ml compared with the untreated sludge, which was an increase of 38.93% compared...

Embodiment 2

[0022] The properties of the remaining sludge in a sewage treatment plant after gravity settlement are shown in the table below.

[0023]

[0024] Use 22kHz, 0.2w / ml ultrasonic treatment for 3 minutes, and the dosage of NaOH is 0.02g / gTS. Put it in a shaker at 25±2°C for 24 hours, then take 200ml of combined pretreatment sludge and send it to an anaerobic digestion reactor, and put it in a shaker at 35±2°C for mesophilic anaerobic digestion. The soluble COD in the treated sludge increased to 990.329mg / L, about 14 times higher than that of the untreated sludge. After 14 days of anaerobic digestion of sludge pretreated by ultrasonic and NaOH, the amount of methane produced was basically the same as that of untreated sludge after 22 days of anaerobic digestion. However, under the conditions of 22 days of digestion of the two kinds of sludge, the amount of methane produced was 302.2ml, which was 40.5% higher than that of the untreated sludge.

Embodiment 3

[0026] The properties of the remaining sludge in a sewage treatment plant after gravity settlement are shown in the table below.

[0027]

[0028] Use 21kHz, 2.0w / ml ultrasonic treatment for 3 minutes, and the dosage of NaOH is 0.08g / gTS. Put it in a shaker at 25±2°C for 24 hours, then take 200ml of combined pretreatment sludge and send it to an anaerobic digestion reactor, and put it in a shaker at 35±2°C for mesophilic anaerobic digestion. The soluble COD in the treated sludge increased to 7800.00mg / L, about 52 times higher than that of the untreated sludge. After 13 days of anaerobic digestion of sludge pretreated by ultrasonic and NaOH, the amount of methane produced was basically the same as that of untreated sludge after 22 days of anaerobic digestion. However, under the conditions of 22 days of digestion of the two kinds of sludge, the amount of methane produced was 302.24ml, which was 40.6% higher than that of the untreated sludge.

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Abstract

The invention belongs to the technical field of solid waste treatment, in particular relates to a combined pre-treatment method for improving sludge disintegration effect and strengthening subsequent anaerobic digestion, comprising the following concrete steps of: gravity settling and thickening residual sludge generated in a secondary settling tank of a municipal sewage treatment plant, sending the thickened sludge into an ultrasonic reactor for ultrasonic irradiation and adding NaOH; sending the sludge into a sludge anaerobic digestion reactor for subsequent medium temperature anaerobic digestion after the combined action of ultrasonic and NaOH; and collecting methane generated by digestion and measuring the yield of the methane with a gas collection device. The method firstly uses ultrasonic and NaOH jointly for sludge treatment, the soluble COD concentration in sludge liquid phase after treatment is improved by about 52 times, the methane yield is improved by 40.6 percent, and the problem of limited application of ultrasonic due to high energy consumption is largely overcome; and the method is applicable to the treatment of residual sludge in sewage treatment plants, and can be achieved by making corresponding modification on the current treatment facilities of sewage treatment plants for different-scale sewage treatment plants, thus having wide application prospect.

Description

technical field [0001] The invention belongs to the technical field of solid waste treatment, and in particular relates to a method for combined pretreatment to improve sludge cracking effect and strengthen subsequent anaerobic digestion. Background technique [0002] A large amount of sludge is produced in the process of sewage treatment, and its quantity accounts for about 0.3%-0.5% of the treated water (based on a water content of 97%). With the popularization of sewage treatment facilities, the increase of treatment capacity, the improvement of treatment standards and the expansion of treatment functions, the generation of sludge will still increase significantly. It is estimated that the output of sludge in 2010 will be 5 times that of 2001. The investment and operation cost of sludge treatment is very huge, and the cost of sludge treatment accounts for 20%-50% of the operation cost of sewage treatment plant, even as high as 60%, which brings a heavy burden to sewage t...

Claims

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Application Information

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IPC IPC(8): C02F11/00C02F11/04C02F11/12C12M1/107
CPCY02E50/343Y02E50/30
Inventor 周琪胡亚冰张超杰张辰王国华谭学军
Owner TONGJI UNIV
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