Off-line cleaning method for reverse osmosis membranes

Abstract

The invention discloses an off-line cleaning method for reverse osmosis membranes, which comprises the following steps of: 1) preparation of a cleaning solution with pH value of 10-13, wherein the cleaning solution comprises the following components in percentage by weight: 2-3% of sodium tripolyphosphate, 0.25-0.5% of sodium hydroxide solution, 0.25-0.5% of sodium dodecyl benzene sulfonate solution, and the balance of pure water; 2) ultrasonic cleaning: placing the reverse osmosis membranes into an ultrasonic cleaner, and ultrasonically oscillating to drop off the dirt from the surfaces of the reverse osmosis membranes; 3) circulatory cleaning: placing the reverse osmosis membranes into membrane shells, pumping the cleaning liquid medicine in a cleaning liquid storage tank into the membrane shells by a water supply pump so as to wash the reverse osmosis membranes, and recirculating the cleaning solution to the cleaning solution storage tank; circularly cleaning at low flow for 30-35 min, wherein the flow of a pressure container of each reverse osmosis membrane is 50-100L / min; circularly cleaning at high flow for 1-2 h, and the flow of a pressure container of each reverse osmosis membrane is 101-150L / min; and 4) washing: washing by pure water at low pressure for 20-30 min, thereby guaranteeing to remove the cleaning solution and impurities.

Description

Technical field: [0001] The invention belongs to reverse osmosis cleaning technology, in particular to a reverse osmosis membrane off-line cleaning method, which removes pollutants deposited on the surface of the reverse osmosis membrane through ultrasonic immersion cleaning and chemical cleaning, and is suitable for off-line cleaning of the reverse osmosis membrane. At the same time, the system detects the salt rejection rate and flux of a single membrane. Background technique [0002] As a deep filtration method, reverse osmosis membrane elements have been widely used in various water treatment systems. The principle is: the reverse osmosis membrane is a semi-permeable membrane with selective permeability. In the natural process, the side with lower salt content will flow to the side with higher salt content through the semi-permeable membrane. Call it osmosis until equilibrium is reached, which is the static pressure difference on both sides of the membrane is the osmoti...

AI Technical Summary

Problems solved by technology

[0012] The purpose of the present invention is to provide a reverse osmosis membrane off-line cleaning method, which can greatly improve the cleaning effect and avoid repeated cleaning of the reverse osmosis membrane for the problems of poor cleaning effect, repeated cleaning and easy damage to the membrane in the off-line reverse osmosis cleaning , while reducing the damage period and prolonging the service life

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