Chemical cleaning method of hollow fiber membrane and device thereof

Abstract

The invention discloses a chemical cleaning method of a hollow fiber membrane, comprising the following steps of: (1) preparing a composite chemical cleaning agent with the active chlorine concentration of 10-13%; and (2) back washing the hollow fiber membrane on line by adopting the compounded composite chemical cleaning agent. The invention also discloses a chemical cleaning device of the hollow fiber membrane, which is provided with a composite chemical cleaning agent storage tank and a back washing system comprising a back washing pump; and the upper part of the storage tank is provided with a filling pipe, an electromagnetic valve and an air release valve. The invention can effectively keep the membrane flux of a membrane bioreactor and is matched with the running characteristic of a membrane bioreactor process. The invention solves the problems of large impact on microorganisms in a system, high labor intensity caused by needing to hang a membrane assembly out for cleaning and the like, and difficult running management, can integrate a membrane assembly cleaning system and the membrane bioreactor to improve the control level of automation. By adding a surfactant and regulating the pH value of the system to be greater than 13, the stability of a sodium hypochlorite solution can be improved.

Description

technical field [0001] The invention relates to cleaning, in particular to a chemical cleaning method and device for a hollow fiber membrane. Background technique [0002] The hollow fiber membrane of the membrane bioreactor has a small pore size and is easily blocked by pollutants during operation, resulting in an increase in membrane pressure and a decrease in flux. A cleaning method must be used to quickly restore membrane flux. Among the currently commonly used cleaning methods for membrane bioreactors, chemical cleaning is the most economical and effective, and has become the main method of chemical cleaning for membrane bioreactors. However, there are the following problems: [0003] 1) If the membrane module is hoisted out as a whole and the pollutants on the surface are soaked and cleaned off-line with chemical agents, lifting equipment and a special membrane washing tank are required, which is complicated to operate and labor-intensive; while soaking and cleaning d...

AI Technical Summary

Problems solved by technology

[0003] 1) If the membrane module is hoisted out as a whole and the pollutants on the surface are soaked and cleaned off-line with chemical agents, lifting equipment and a special membrane washing tank are required, which is complicated to operate and labor-intensive; while soaking and cleaning directly in the reactor consumes chemicals The dosage is large, the waste is serious, and the cost is high;

[0004] 2) Sodium hypochlorite, a commonly used chemical cleaning agent, is unstable in chemical properties and difficult to store for a long time under normal temperature conditions. It can only be prepared and used by supporting industries. It is not suitable for application in counties and rural areas where supporting industries are relatively backward and the purchase of pharmaceuticals is inconvenient. It is a constraint Important factors for the application of membrane bioreactors in decentralized sewage treatment;

[0005] 3) A rapid recovery method is only adopted when the fouling of the membrane material is so serious that the system cannot operate stably. The concentration of chemical cleaning agent is high, which has a great impact on the microorganisms in the system and will cause damage to the membrane material, and it is not suitable for daily use. Maintenance and Cleaning

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