Chemical cleaning method for inner-pressure-type membrane system

Abstract

The invention relates to a chemical cleaning method for an inner-pressure-type membrane system, and belongs to the field of water processing, and the method is applicable to systems of ultrafilter membranes, micro-filtration membranes and the like. The cleaning steps comprise: firstly performing positive flushing; employing chlorine-containing water to perform reverse cleaning; employing chlorine-containing water to perform isobaric flushing; and performing a filtering water-producing stage by employing the membrane system and the like. The provided membrane-system chemical cleaning method employs an on-line cleaning manner, solves the membrane-system outage problem caused by employing of conventional chemical cleaning methods, and also does not influence water producing of the membrane system during chemical cleaning, so that the working efficiency is substantially improved; the provided membrane-system chemical cleaning method employs a conventional membrane-system reverse flushing method, and is simple in operation, and no new chemical cleaning equipment needs adding on the basis of conventional equipment; because the employed chlorine-containing water is relatively low in chlorine concentration, so that requirements on the anticorrosive performance of shells, equipment and the like is relatively low; and because the employed efficient chlorine density is relatively low, the chemical backwashing waste liquid is convenient for processing and recycling.

Description

technical field [0001] The invention relates to a chemical cleaning method for an internal pressure membrane system, which belongs to the field of water treatment and can be used for systems such as ultrafiltration membranes and microfiltration membranes. Background technique [0002] Membrane technology, including microfiltration membrane and ultrafiltration membrane, is one of the technologies widely used in the field of water treatment technology. In actual production, it is found that membrane fouling will occur after the membrane has been in operation for a period of time, resulting in an increase in the transmembrane pressure difference or a decrease in the membrane flux. After membrane fouling occurs, chemical cleaning is generally used to eliminate membrane fouling. During chemical cleaning, high-concentration acid (hydrochloric acid or citric acid), alkali (sodium hydroxide) or oxidant (sodium hypochlorite) is generally used to soak or circulate the membrane. Due ...

AI Technical Summary

Problems solved by technology

In the previous immersion cleaning method, it is difficult to quickly and directly clean the pollution out of the membrane system, so the effect of immersion cleaning is poor; and in the circulation cleaning method, since the pollutants that have been cleaned return to the internal pressure with the circulating cleaning solution In the membrane system, the effect of cycle cleaning is not ideal

Images