Chemical cleaning method for reverse osmosis membrane element

Abstract

The invention relates to a chemical cleaning method for a reverse osmosis membrane element, and belongs to the technical field of water treatment. The method comprises the following steps: (1) soaking a first section and a second section of the reverse osmosis membrane element by using an isothiazolinone solution with the content of active matters of 5 to 7 percent, wherein the soaking time is not less than 6 hours; (2) judging a pollutant polluting the reverse osmosis membrane element, and then selecting corresponding chemical cleaning agents; (3) according to chemical cleaning agents selected in the step (2), cleaning the reverse osmosis membrane element in the following three situations, namely cleaning the reverse osmosis membrane element by only using an acid cleaning agent, cleaning the reverse osmosis membrane element by only using an alkaline cleaning agent, and cleaning the reverse osmosis membrane element by using the acid cleaning agent and the alkaline cleaning agent simultaneously. The cleaning effect of the chemical cleaning method is obviously better than that of a conventional cleaning formula; the water yield and the recovery rate can be increased obviously; the operating pressure difference and the conductivity of produced water of reverse osmosis equipment can be reduced; meanwhile, the damage to the membrane element caused by the chemical cleaning times and the chemical agents when the membrane element is cleaned is reduced.

Description

technical field [0001] The invention belongs to the technical field of water treatment, and in particular relates to a chemical cleaning method for a reverse osmosis membrane element. Background technique [0002] As a new water treatment technology, reverse osmosis membrane separation has penetrated into various industrial fields. In the actual application process, the membrane elements provided by reverse osmosis membrane manufacturers are widely universal and lack pertinence. Most of the cleaning methods provided by various manufacturers are simple acid and alkali repeated cleaning, such as HCl and NaOH. However, due to the large differences in water sources and water quality among enterprises, there is insufficient understanding of membranes and lack of experience in membrane engineering applications. Especially for the treatment of low temperature (water temperature is lower than 12°C in summer), low turbidity (fresh water turbidity is lower than 1~2ntu), high organic...

AI Technical Summary

Problems solved by technology

After the membrane element is polluted, the service efficiency and life of the membrane element will be greatly reduced due to improper cleaning formula or cleaning method, which usually leads to low actual treatment efficiency of the system, high operating cost, and unstable operation of the membrane system. Simplified as changing membranes constantly, eventually leading to loss of confidence in membrane technology and increased operating costs

[0003] Some enterprises entrust the chemical cleaning of reverse osmosis membranes to professional cleaning companies. Because the chemical cleaning formula and cleaning methods of the membranes are universal and lack pertinence, there are cleaning methods and cleaning agent dosages, and the selection of cleaning agents is unreasonable. and other problems, resulting in incomplete cleaning of the membrane, poor cleaning effect, increased cleaning times, and the conductivity of the product water after cleaning increased significantly by 2-3 μs / cm, resulting in an increase in the conductivity of the product water of the reverse osmosis equipment, a decrease in the recovery rate, and an impact on The service life of reverse osmosis membrane