High speed water purification and efficient phosphate rejection by active nanofibrous membrane for microbial contamination and regrowth control

This work described a new strategy of prohibiting the microbial intrusion in drinking water, which consisted of a fast membrane filtration to remove cells and an efficient phosphate starvation to reduce recontamination. The La(OH) 3 nanorod/polyacrylonitrile (PAN) nanofiber membrane filters were made by electrospining and a subsequent in-situ precipitation process. The membrane displayed a high water flux (1010 L m −2  h −1 ) at low pressure (0.1 bar) due to the hydrophilic and highly-porous property of PAN nanofiber matrix. Besides, the membrane presented several remarkable features due to the impregnation of the functional component La(OH) 3 nanorods, such as a reduced pore sizes, an enhanced mechanical property and a positively charged membrane surface, which all supported the great retention of bacteria during microfiltration (the log reduction reached 7). Furthermore, based on the high efficient and high speed binding between Lanthanum and phosphate, the composite nanofibrous filter had an excellent phosphate rejection (97% removal) to achieve the control of bacterial regrowth by nutrient starvation. The antibacterial performance over practical tap water exhibited both a high removal of cells and a great control of recontamination, implying the application potential of this new strategy.