Abstract

Biofouling presents difficult problems for seawater reverse osmosis (SWRO). Although iron nanoparticles (FeNPs) exhibit anti-biofouling properties, this may vary with geographic location. The efficacy of an FeNP coating for SWRO membranes is studied at laboratory scale in two sites – Sea of Cortez, Mexico (27.917°N, 110.776°W), and El Sol Beach, Chile (33.01°S, 71.553°W) – with significant differences in physicochemical parameters. Constant concentrations (109 CFU mL−1) of native strains Bacillus halotolerans MCC1 and Bacillus sp. TA011_2 (EU308309), were respectively used at each of the sites to promote biofouling. The biofilm thickness, total, viable and non-viable cell counts, and organic matter were analyzed. More biofouling (>74%) was observed at the Mexican site due to differences in temperature and pH, but the coating presented stronger biocide effect (by 29%) there. Temperature, dissolved oxygen and pH had a more significant effect than salinity on biofouling FeNP coated membranes.