Durability and Regeneration of Functional Membrane Coatings for Wastewater Treatment

Functional membrane coatings enhance wastewater treatment by regulating interfacial transport, suppressing fouling, and introducing selective or reactive sites. However, their practical effectiveness depends on maintaining these functions during prolonged operation and repeated regeneration. This review examines how coating chemistry, morphology, and attachment to porous supports govern treatment performance, deterioration, and recovery. The reviewed studies were published during the period 2015–2026. Hydration-mediated fouling resistance, selective transport, adsorption, and catalytic conversion are discussed in relation to their distinct failure mechanisms and regeneration requirements. Particular attention is given to the distinction between hydraulic recovery and restoration of pollutant-removal function: recovered water flux does not necessarily indicate renewed adsorption capacity or catalytic activity, while high rejection can persist despite substantial throughput loss. Physical cleaning, chemical desorption, assisted cleaning, and layer renewal are critically compared in terms of functional recovery, coating retention, cumulative damage, and resource consumption. The analysis identifies paired hydraulic and pollutant-specific measurements, together with useful treated volume, as a basis for evaluating regeneration effectiveness. Finally, priorities are outlined for validating coating durability in complex wastewaters, quantifying material release and secondary wastes, and establishing reliable lifecycle and cost comparisons.