Enhanced antifouling performance of cellulose acetate membranes via tannic acid–ferric ion coatings for microalgae harvesting

The development of tannic acid (TA) and Fe³⁺ modified cellulose acetate (CA) membranes offers a promising approach to improving filtration performance in bioresource applications, particularly for microalgae harvesting. This study aimed to evaluate the effects of TA/Fe³⁺ coatings on the antifouling properties, permeability, and filtration efficiency of CA membranes. Using a layer-by-layer assembly method, single and multi-layer coatings were applied and analyzed. Results demonstrated that single-layer coatings achieved optimal permeability and fouling resistance, with flux recovery ratios of up to 98 %, while multi-layer coatings reduced the membrane water flux. The incorporation of TA/Fe³⁺ complexes improved hydrophilicity and introduced electrostatic repulsion, significantly reducing fouling by algal cells and extracellular organic matter. These findings underscore the potential of TA/Fe³⁺ coatings in creating efficient, scalable, and sustainable membrane solutions for bioresource management. Future research should explore the long-term stability and broader applications of these coatings in diverse filtration systems.