Development of antifouling nanofiltration membrane with zwitterionic functionalized monomer for efficient dye/salt selective separation

Abstract

Nanofiltration (NF) membranes offer advantages to address enormous demands for textile water treatment. To meet omnipresent challenges of dye/salt selectively and antifouling performance, an efficient dye desalting and antifouling NF membrane was developed by virtue of zwitterionic functionalized monomer (zwitterionic N,N-Bis(3-aminopropyl)methylamine, ZDNMA). The structures of zwitterionic membranes can be tailored to suit the separation performance and antifouling property. The prepared zwitterionic NF membrane shows superior removal performance of methyl blue and penetration capacity of NaCl due to zwitterion desirable features of accelerating NaCl transportation. Thus, the membrane selectivity factor for NaCl/methyl blue can be as high as 857.0, accompanied by pure water flux of 10.67 L m-2 h-1 bar-1. When dealing with 0.3 g L-1 MYB and 4 g L-1 NaCl mixture solution, a high NaCl removal was achieved in 75.8% with about 8.1% dye loss after dye purification process. Furthermore, the membrane revealed antifouling performance with a 94.9% flux recovery ratio. The zwitterionic NF membrane highlights more exceptional dye desalination performance, which renders a vast potential for practical textile effluent.