Biofilm increases permeate quality in low pressure ultrafiltration due to carbon degradation

This study investigated the extent of fouling and concentration polarization due to Natural Organic Matter (NOM) of various compositions in the NF and UF membranes with molecular weight cut offs (MWCOs) ranging from 150 to 8,000 Da. NOM substances were represented by polysaccharide alginate and humic substances derived from Suwannee River (SRNOM). Tests were also conducted with a natural surface water containing a wide range of different NOM constituents. Samples containing the polysaccharide alginate exhibited a higher extent of fouling than samples containing humic substances. Concentration polarization did not seem to be a main contributor for flux decline due to NOM in NF and UF range membranes.