What Chemicals Can Be Used to Disinfect RO Membranes Directly

11 What Chemicals Can be Used to Disinfect RO Membranes Directly  

For biocide treatment directly on the membranes, DBNPA is a good non-oxidizing biocide (see Chapter 8.2.5.2). For clean membranes, a dosage of about 100 ppm for 30 minutes 2 to 3 times per week is recommended. For heavier fouling, 100 ppm for 60 minutes 2 to 3 times per week should be fed. Alternatively, DBNPA can be fed continuously at about 2-3 ppm. Note that once biofouling gets out of control, it will be very difficult for DBNPA to work, because it is a non-oxidizer and cannot penetrate biofilm. DBNPA works best as a preventative treatment. 

Isothiazolone can be used as a cleaner, but not for slug treatment, as it requires a longer contact time than DBNPA (see Chapter 8.2.5.3). When cleaning with isothiazolone, it should be allowed to contact the membrane for at least 4 hours. 

For biocide treatment directly on the membranes, DBNPA is a good nonoxidizing biocide (see Chapter 8.2.2.2 and 8.5.2.2.1). For clean membranes, a dosage of 30-50 ppm for 30 minutes 2 to 3 times per week is 

Isothiazolone can also be fed on a continuous basis and is an excellent method to keep membrane free of microbial growth. The recommended methods of using isothiazolone are the direct method and the post-cleaning method  

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