Eco-infused interfacial enhancement of the anti-biofouling activity in anion exchange membranes for electrodialysis desalination

Abstract

Strengthened surface modification via bio-safety and eco-friendly agent requirements, and the development of the antibacterial anion exchange membrane (AEM) has become crucial for resource recovery with water-sustainable management to effectively mitigate bacteria-related fouling control. A synergistic antibacterial system of lysozyme and tetrakis(hydroxymethyl)phosphonium sulfate (THPS) is explored here that is immobilized onto the surface of commercial AEM with L-dopa. Compared to the single biomacromolecule lysozyme, THPS performs a vital role in this functional layer by compensating for the insensitivity of the lysozyme to typical Gram-negative bacteria (Such as E. coli). This system demonstrated excellent antibacterial performance (E. coli and S. aureus were selected as test strains) according to the “contact-sterilization”, and the change with contact time was systematically investigated. Based on confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) examination of live and dead bacteria, it was showed that the as-modified membranes by synergistic antibacterial mechanism revealed effective inhibition of biofilm growth. Moreover, these modified layers demonstrated high stability in electrodialysis (ED) desalination systems. The bio-friendly and robust anti-biofouling characteristics of this approach offer valuable insights for constructing antibacterial surfaces in similar applications.