Recent advances in polyamide nanofiltration membranes for antibiotic removal

Emerging as a new class of micropollutants in the last several decades, antibiotics are difficult to remove through conventional technologies and therefore can persist long-term in natural aquatic environments. Polyamide (PA) nanofiltration (NF) membranes are reportedly highly suitable for treating antibiotic-containing water; however, they still face such challenges as permeability-selectivity trade-off and membrane fouling. This review aims to introduce the latest developments and advancements in membranes over the last five years. Five strategies of novel monomers, additive doping, interlayers, surface grafting, and post-treatment are used in developing more efficient PA-NF membranes to promote permeability, selectivity, and antifouling ability. Novel monomers strategy enables tailored design of PA structures; additive doping and interlayers strategies more effectively overcome the permeability-selectivity trade-off; surface grafting strategy endows membranes with unique features; post-treatment strategy offers the broadest versatility. Multiple processing parameters (solution pH, pressure, temperature, and ionic strength) would affect membrane performance; particularly, solution pH is most important and hence must be carefully monitored and controlled to minimize membrane fouling and optimize treatment efficiency, as it can affect both the properties of membranes and antibiotics. Future research should focus on the feasibility of these strategies for large-scale and sustainable development.