Fouling behavior of marine organic matter in reverse osmosis membranes of a real-scale seawater desalination plant in South Korea

The effects of marine organic matter (MOM) characteristics on the fouling layer composition of seven parallelly arranged reverse osmosis (RO) membrane modules were identified to offer valuable insights into the fouling behavior of MOM in a real-scale seawater desalination plant in the South Korea region. Although both hydrophobic (HPO) and hydrophilic (HPI) MOM fractions governed the fouling formation of the RO membranes, HPO MOM fractions complexed with multivalent metal ions (i.e., Al, Ca, Cu, Fe, and Mg) were found to be major contributors to the irreversible fouling of the RO membranes. Despite the efficient recovery of the negative surface zeta potential after the cleaning procedures with deionized water, base and acid solutions, the contact angle of the fouled RO membrane was reduced significantly, which was more pronounced for the cleaned RO1st membranes than the cleaned RO7th membranes. HPI MOM fractions were preferentially deposited onto the membrane surfaces in the RO1st module, while residual HPO MOM fractions strongly contributed to the fouling formation of the RO membranes in the RO7th module. These phenomena might lead to significant differences in the fouling layer composition of the RO membrane modules in the real-scale seawater desalination plant in the South Korea region.