Summary of RO ro RO membrane cleaning methods

Ro RO reverse osmosis membrane cleaning scheme is divided into physical method and chemical method, both of which can effectively clean the membrane: physical method: this method uses mechanical force to remove pollutants on the membrane surface There is no chemical reaction during the whole cleaning process 1 This method is a kind of original but effective method The mother's method is to gently wipe the dirt on the membrane surface with soft material (such as sponge) and wash it off with water while wiping This method can effectively remove a large number of dirt on the membrane surface But it can't do anything for the finer impurities in the membrane pores 2 This method can be used for membrane cleaning of any type of ultrafiltration module The specific method is to close the water production valve, open the concentrated water outlet valve, and wash the membrane surface by increasing the flow rate, which is effective for removing a large number of soft impurities on the membrane surface The effect of constant pressure washing is also related to the frequency of continuous washing 3 The reverse washing method is a method of washing from the back (porous support layer) to the front (dense layer) This is an effective cleaning method After backwashing the membrane, the water flushing method with equal pressure is carried out, and the cleaning effect is very obvious 4 The hot water washing method uses the heated water (30-40 ~ C) to wash the membrane surface, which has obvious removal effect on the thick and hot soluble impurities (such as sugar) 5 The purified compressed air and water will be sent to the ultrafiltration device by the water air mixed cleaning method The water air mixed flow will produce violent agitation on the membrane surface and remove the stubborn impurities The effect is also good Chemical method: the purpose of cleaning the membrane is achieved by chemical reaction between a certain chemical and the filter cake on the membrane surface The principle of selecting chemicals for RO membrane cleaning: first, no chemical reaction with membrane and other component materials; second, no secondary pollution due to the use of chemicals When chemical cleaning method is used, equal pressure washing and reverse washing are often combined, so as to remove pollutants on the membrane surface more effectively 1 The oxidation cleaning agent uses 1% ~ 3% H2O2, 500 ~ 1000mg / lnacl0 and other aqueous solutions to clean the 4040 reverse osmosis membrane, which not only removes the dirt, but also kills the bacteria H2O2 is a commonly used bactericide 2 Adding enzyme detergent, such as 0.5% - 1.5% pepsin, trypsin and so on, is effective to remove protein, polysaccharide, grease and other pollutants during the 4040 reverse osmosis membrane cleaning RO membrane element is an important part of water treatment system, so it is necessary to clean RO membrane regularly.