Micropollutant removal capacity and stability of aquaporin incorporated biomimetic thin-film composite membranes

Abstract

Aquaporin incorporated nanofiltration membranes have high potential for future applications on separation processes. In this study, performance of biomimetic thin-film composite membranes containing Halomonas elongata and Escherichia coli aquaporins with different affinity tags for the removal of micropollutants was investigated.% rejection of the membranes for atrazine, terbutryn, triclosan, and diuron varied between 66.7% and 90.3% depending on the type of aquaporin and micropollutant. The highest removal rate was achieved with a membrane containing H. elongata aquaporin for atrazine and terbutryn which have methyl branching in their structure. Electrostatic interactions between micropollutants, thin-film layer of the membrane, and tags of aquaporins may also play important role in rejection of micropollutants. Stability experiments showed that biomimetic membranes can be used for six months period without a remarkable decrease in% rejection. Membrane used 24 times for atrazine removal for a year period lost most of its ability to repel atrazine.