Fully automatic control nanofiltration membrane on-line large flushing method

Abstract

The invention discloses a full-automatic control nanofiltration membrane online strong flushing method, for solving the problem that when nanofiltration membrane is used for treating reverse osmosis concentrate of printing and dyeing wastewater, a membrane flux attenuation rate is high due to high-concentration chloride, persistent organic pollutants, aluminum salts and the like; the method comprises production operation of a nanofiltration membrane system and strong flushing operation; pollutants on the surface of the nanofiltration membrane is periodically flushed according to set time of a membrane system controller; according to the full-automatic control nanofiltration membrane online strong flushing method, the nanofiltration membrane core is periodically strongly flushed by raw water, so that pollution to the membrane surface can be effectively relieved, thus playing roles in prolonging stable operating period of the membrane system, automatically controlling a whole process, and being simple, convenient, short in time and significant in effect.

Description

technical field [0001] The invention discloses a method for fully automatic control of nanofiltration membrane on-line flushing, which belongs to the technical field of nanofiltration membrane on-line flushing according to the International Patent Classification (IPC), and particularly relates to a method for advanced treatment and reuse of sewage in printing and dyeing enterprises. Flushing method for membrane surface contamination of nanofiltration system caused by roots, refractory organic pollutants, aluminum salts, etc. Background technique [0002] At present, the printing and dyeing industry generally adopts reverse osmosis membrane treatment as the main method for advanced sewage treatment and reuse. The concentrated reverse osmosis water mainly contains high concentrations of chlorine radicals, refractory organic pollutants, aluminum salts, etc. The use of nanofiltration membrane systems can further improve water recovery. However, due to the high concentration of p...

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Problems solved by technology

[0002] At present, the printing and dyeing industry generally adopts reverse osmosis membrane treatment as the main method for advanced sewage treatment and reuse. The concentrated reverse osmosis water mainly contains high concentrations of chlorine radicals, refractory organic pollutants, aluminum salts, etc. The use of nanofiltration membrane systems can further improve water recovery. rate, but due to the high concentration of pollutants in the influent, the pollution speed is fast, and the sustainable operation time of the system is short

[0003] The existing reverse osmosis or nanofiltration system pollution prevention and control mainly adopts the method of adding special cleaning materials or air-water cleaning, which basically requires the addition of chemicals or materials, the cleaning procedures are complicated, and the cleaning time is long

Chinese document CN 103301753A discloses a cleaning method for preventing and controlling reverse osmosis membrane or nanofiltration membrane pollution. Specifically, air-water cleaning or chemical cleaning is first used, and then the pretreated water is replaced with reverse osmosis or nanofiltration concentrated water, and finally discharged. Membrane cleaning scheme cannot realize online processing, and chemical cleaning method needs to add chemicals

[0004] In the printing and dyeing industry, nanofiltration reuses reverse osmosis concentrated water, often with high pollution and short running time. Therefore, if conventional chemical cleaning is used, the system needs to be stopped for special cleaning treatment, which affects the efficiency of printing and dyeing wastewater treatment.

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