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Chemical cleaning method of ultrafiltration membrane for metallurgical sewage pretreatment

A technology of sewage pretreatment and chemical cleaning, applied in metallurgical wastewater treatment, chemical instruments and methods, osmosis/dialysis water/sewage treatment, etc., can solve the problems of ultrafiltration membrane blockage and restore ultrafiltration system processing capacity

Inactive Publication Date: 2010-12-15
QINHUANGDAO SHOUQIN METAL MATERIAL +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a method for chemical cleaning of ultrafiltration membranes for metallurgical sewage pretreatment, which can perform online chemical cleaning of ultrafiltration membranes, solve the problem of ultrafiltration membrane clogging, and restore the processing capacity of ultrafiltration systems

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0007] Example 1: Wash with 0.25% sodium hydroxide for 10 hours, and wash with 3% citric acid for 5 hours. After chemical cleaning, the maximum water inlet pressure drops from 0.014Mpa to 0.007Mpa, and the transmembrane pressure drop drops from 0.0085Mpa to 0.002Mpa. The cleaning effect is very obvious.

Embodiment 2

[0008] Example 2: washing with 0.5% sodium hydroxide for 10 hours, and washing with 4% citric acid for 5 hours. After chemical cleaning, the maximum water inlet pressure is reduced from 0.011Mpa to 0.007Mpa, and the transmembrane pressure difference is reduced from 0.008Mpa to 0.002Mpa. many.

Embodiment 3

[0009] Example 3: 0.2% sodium hydroxide cleaning for 10 hours, 3% citric acid cleaning for 5 hours. After chemical cleaning, the maximum water inlet pressure dropped from 0.013Mpa to 0.008Mpa, and the transmembrane pressure dropped from 0.0082Mpa to 0.004Mpa, and the cleaning effect was poor.

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PUM

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Abstract

The invention discloses a chemical cleaning method of an ultrafiltration membrane for metallurgical sewage pretreatment and belongs to the technical field of metallurgical sewage treatment. The method comprises the following steps of: cleaning the ultrafiltration membrane with sodium hydroxide at the concentration of 0.25 to 0.3 weight percent for 8 to 12 hours; and then cleaning the ultrafiltration membrane with citric acid at the concentration of 2.5 to 3.5 weight percent for 4 to 7 hours, wherein after the cleaning, the maximal feed water pressure of ultrafiltration facilities is reduced from 0.012-0.014MPa to 0.006-0.0075MPa; and the transmembrane differential pressure is reduced from 0.0085-0.0085MPa to 0.002-0.003MPa. The chemical cleaning method has the advantages of prolonging the running period from 15 days to 40 days after the cleaning, reducing the frequency of chemical cleaning and saving chemical agents. The ultrafiltration membrane system realizes long-time continuous stable running and is favorable for ensuring the continuous stable running of desalting facilities.

Description

technical field [0001] The invention belongs to the technical field of metallurgical sewage treatment, and in particular provides a chemical cleaning method for ultrafiltration membranes for pretreatment of metallurgical sewage. Background technique [0002] Japan Asahi Kasei ultrafiltration membrane, according to the cleaning method instructions provided by the manufacturer, was cleaned with 2000-5000ppm sodium hypochlorite + 1% sodium hydroxide solution, and then washed with 2-5% acid for 2 hours. For the above-mentioned cleaning method, from theoretical analysis, sodium hypochlorite disinfection should be able to exert the greatest effect in an environment with a low pH, but this cleaning method is under alkaline conditions, which is not easy to exert the best disinfection effect; in addition, When the ultrafiltration system is running, backwashing is performed every half an hour, and sodium hypochlorite is added for disinfection during backwashing. It is not necessary to...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01D65/06B01D61/14C02F1/44C02F103/16
Inventor 张强张立伟高天力王亮
Owner QINHUANGDAO SHOUQIN METAL MATERIAL