New disinfectant to control biofouling of polyamide reverse osmosis membranes

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Biofouling control in polyamide reverse osmosis (RO) membrane processes has been restricted since the membranes are vulnerable to chlorine – which is an effective disinfectant for water treatment. Chlorine eventually reduces salt rejection and shortens membrane life expectancy.

This Korean study investigated dichloroisocyanurate (DCC) for biofouling control in polyamide RO membrane processes, which could be employed as a cleaning-in-place (CIP) agent or as a disinfectant in pretreatment.

The evaluation of DCC consisted of membrane performance tests and the antimicrobial effect in comparison with chlorine under identical conditions.

Permeate flux, salt rejection, and surface characterisation were examined as membrane performance indicators after exposure to disinfectants. The antimicrobial effect of DCC was investigated on biofilms grown on the membrane surface.

The results showed that normalised salt rejections of DCC-exposed membranes were maintained at 99% without any sacrifice in flux, while those for chlorine-exposed membranes decreased to 80%.

The biofilms grown on the RO membrane were inactivated by DCC as much as by chlorine. This study suggests the excellent possibility of utilising DCC  for biofouling control in RO processes.

Journal of Membrane Science, Volume 427, 15 January 2013, Pages 30–36.