A GO-based biocatalytic membrane prepared by one-step pressure-assisted self-assembly for micropollutants removal

Biocatalytic membranes are a green and effective option for the removal of micropollutants (MPs) from water. The effective immobilization of enzyme together with facial fabrication of membrane is constantly required. Herein, a biocatalytic membrane was prepared by one-step pressure-assisted self-assembly of graphene oxide (GO), polyethyleneimine (PEI) and laccase (Lac) on the surface of hydrolyzed polyacrylonitrile (HPAN) membrane. The physical and chemical property of membranes, and the immobilization of laccase were characterized. Under optimal conditions, the biocatalytic membrane has a bisphenol A (BPA) removal rate of 95.3%, and the rejection for dyes can be higher than 97% with salts rejection of less than 23% and pure water permeance of 207.4 LMH/bar. Meanwhile, GO-PEI-Lac membrane retained stable removal rate under a wide pH range and feed BPA concentrations. The membrane can also remove various phenolic MPs. In addition, the GO-PEI-Lac membrane retained more than 80% removal rate after 6 cycles. Overall, this study opens up a convenient avenue for the facial fabrication of high-efficient biocatalytic membranes for MPs removal.