Gravity-driven multifunctional microporous membranes for household water treatment: Simultaneous pathogenic disinfection, metal recycling, and biofouling mitigation

Abstract

In remote industrial areas, access to safe drinking water is often hindered by local water contamination and unreliable infrastructure. Hence, energy-effective water treatment and safe storage technology is vital and highly desirable to tackle complex water pollution caused by heavy metals and pathogenic contaminants for boundary circumstances. Here, we originally engineered a multifunctional gravity-driven membrane system to provide a household-level approach to pathogenic disinfection and biofouling prevention. Facile one-step polyphenol deposition strategy was applied on microporous membranes, tailoring the membrane surface with enhanced positive charge, favorable hydrophilicity and metal-binding ability. When applied in gravity-driven filtration of simulated multi-component wastewater containing heavy metals and pathogenic contaminants, the as-prepared membrane achieved >6 log pathogenic reduction. Metal ions could be in-situ captured and stabilized at membrane interface via natural binding and reduction by polyphenol-engineered surface chemistry, endowing ensuing membranes with improved antibacterial activity. By virtue of enhanced membrane surface properties and antimicrobial synergy, such engineered membrane platform showed potent efficacy in biofilm prevention with97% reduced ATP content and easy permeation recovery (>90%) in cyclic operation. This study is promising for developing low-energy and easy-to-use membrane system to improve contaminated water sources in remote and underdeveloped areas at household level.