(554c) Bio-Inspired Coating for Membranes and Feed Spacers: Managing Biofouling and Controlling Biofilm Populations in Seawater RO Systems

This study addresses the pervasive challenge of biofouling in seawater desalination systems, which compromises membrane performance and longevity. The research introduces a bio-inspired coating that could effectively mitigate biofouling in seawater reverse osmosis systems with minimal environmental impact. The coating is applied to both hydrophilic polyamide membranes and hydrophobic polypropylene feed spacers through in-situ and ex-situ deposition methods, involving a single-step process with polydopamine and sodium-periodate, followed by surface tailoring with citric acid-functionalized tannic acid. Extensive surface characterization confirms coating deposition. Antibiofouling properties are evaluated through long-term biofouling tests simulating industrial conditions. The findings demonstrate that the ex-situ applied coating significantly reduces relative feed channel pressure drop increase due to biofilm growth by 75% and lowers biomass accumulation (88% total cell counts, 70% adenosine-triphosphate, 35% total organic carbon, 91% carbohydrates, and 69% proteins). The coating inhibits the colonization of biofouling-causing bacterial genus Alteromonas, drastically decreases active bacterial gene copy numbers, and alters microbial by-products, leading to reduced biofilm viability and loosely attached biofilms that could enhance cleaning efficiency. With demonstrated durability and stability across various pH conditions, this coating could be a widely applicable and scalable solution for biofouling mitigation in diverse industrial contexts.