Developing a PVDF/nTiO2-(n-1)Fe(OH)3 modified membrane for domestic wastewater treatment in mining areas as an alternative water source for mine backfilling

In this study, the PVDF/nTiO2-(n-1)Fe(OH)3 modified membrane was prepared by the layer-by-layer self-assembly method, and it was applied in the moving bed-ultraviolet photocatalytic membrane bioreactor (MB-UVPMBR) system. The results demonstrate that the modified PVDF/6TiO2-5Fe(OH)3 membrane exhibits excellent hydrophilicity, with the water contact angle reduced to 26°. The pure water flux reaches a maximum of 551.65 L·m− 2·h− 1. Sludge bulking is effectively suppressed, enhancing anti-fouling performance. The initial transmembrane pressure (TMP) value is lower than that of the original membrane, while photocatalytic degradation capability is improved. Within the MB-UVPMBR system, this modified membrane significantly enhances removal rates for total organic carbon (TOC) and chemical oxygen demand (COD) - achieving 96.66% and 94.13% respectively - and markedly delays membrane fouling. The cleaning cycle is extended by 2.74 times compared to conventional polyvinylidene fluoride (PVDF) membranes. This study provides a viable technical pathway for the efficient treatment and reuse of domestic wastewater in backfilling operations, holding significant importance for reducing mine backfilling costs and achieving water resource recycling.