Membrane fouling and cleaning method of brine refining process by membrane method

Abstract

The invention discloses a membrane fouling and cleaning method, in particular to a membrane fouling and cleaning method of brine refining process by the membrane method, which is suitable for chlor-alkali industry and salt making industry, and comprises the following specific steps: firstly, carrying out back flushing for clearing filter cakes deposited on the surface of the membrane; secondly, carrying out acid cleaning for clearing calcium carbonate and magnesium hydroxide particle fouling remained after the back flushing; and finally, cleaning by using a membrane cleaning agent for clearing barium sulfate particle fouling which can not be cleared by the acid cleaning. The membrane fouling and cleaning method provided by the invention has the following beneficial effects of easily obtained raw materials and convenient use, can effectively clear membrane fouling, reduce membrane cleaning frequency, improve the stability of a membrane system, reduce energy consumption, can completely and rapidly restore membrane flux loss, speed up the regeneration of the membrane system, has no damage to the membrane and ensures the consistency of membrane properties before and after cleaning.

Description

technical field [0001] The invention relates to a membrane fouling cleaning method, in particular to a membrane fouling cleaning method suitable for the membrane brine refining process in the chlor-alkali industry and the salt making industry. Background technique [0002] Membrane fouling refers to the phenomenon that certain components in the feed liquid system deposit on the membrane surface or in the membrane pores during the membrane separation process, resulting in a continuous decrease in the membrane filtration flux. In the application process, the membrane must be cleaned and regenerated after the membrane fouling reaches a certain level, so as to restore the filtration flux and retention performance of the membrane. For seriously polluted membranes, it is usually cleaned alternately with strong acid and strong alkali, and oxidants such as sodium hypochlorite and surfactants are added. This method can remove most inorganic and organic pollutants and biological pollu...

AI Technical Summary

Problems solved by technology

Backflushing can restore part of the membrane flux, but due to the adsorption and deposition of some precipitated particles on the membrane surface and in the membrane pores, the pollution cannot be removed by backflushing, and must be removed by acid washing to dissolve the precipitated particles

Pickling has a good removal effect on calcium carbonate and magnesium hydroxide pollution, but because barium sulfate particles are insoluble in acid, the membrane flux cannot be restored due to the continuous accumulation of barium sulfate pollution during long-term operation and cleaning.

Ordinary acid, alkali, and oxidant cleaning methods are extremely ineffective in removing barium sulfate contamination. Replacing membrane elements due to the inability to restore membrane flux will undoubtedly greatly increase costs and affect the application and promotion of membrane brine purification processes.

[0004] At present, there is no membrane cleaning agent suitable for membrane brine refining on the market, and there is no patent publication on the cleaning method of membrane pollution in membrane brine refining. However, the promotion and application of membrane technology in the chlor-alkali industry and the salt industry urgently needs to be developed. A membrane pollution cleaning method suitable for membrane brine purification with easy-to-obtain raw materials, simple operation and outstanding effect