Hybrid gravitational microfiltration system for drinking water purification

Abstract This study evaluates the application of a polymeric microfiltration membrane in a gravitational filtration module and its combination with granular activated carbon (GAC) impregnated with copper, resulting in a hybrid process. The proposed system would be used to improve the quality of water for human consumption in developing countries. Permeate flux, pH, Escherichia coli removal, color, turbidity and free chlorine removals were evaluated in the applied process. Instrumental techniques, such as N2 adsorption at 77 K, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX) analyses were used to characterize the proposed membrane and adsorbent. The GAC ensured higher chlorine removals, as well as higher permeate flux. Furthermore, the GAC impregnated with copper oxide nanoparticles exhibited higher Escherichia coli removal. Therefore, the hybrid gravitational membrane system applying GAC impregnated with copper oxide could be considered as a potential alternative point-of-use treatment to improve the quality of water for human consumption.

摘要
本研究评估了聚合物微滤膜（polymeric microfiltration membrane）在重力过滤模块（gravitational filtration module）中的应用，以及其与负载铜的颗粒活性炭（granular activated carbon, GAC）的组合使用方式，由此构建了一套混合水处理工艺。本研究所提出的这套系统，旨在改善发展中国家的饮用水水质。
本研究所采用的工艺对渗透通量、pH值、大肠杆菌（Escherichia coli）去除率、色度、浊度及游离氯（free chlorine）去除率等性能指标进行了评估。
研究采用77K氮气吸附法、扫描电子显微镜（scanning electron microscopy, SEM）、透射电子显微镜（transmission electron microscopy, TEM）以及能量色散X射线光谱（energy dispersive X-ray spectroscopy, EDX）等表征技术，对所制备的膜材料与吸附剂进行了结构与形貌表征。
负载铜的GAC不仅可获得更高的游离氯去除率，同时还能提升系统的渗透通量。此外，负载氧化铜纳米颗粒的GAC对大肠杆菌展现出更优异的去除效能。
综上，采用负载氧化铜纳米颗粒GAC的重力式混合膜过滤系统，可作为一种极具应用潜力的使用点水处理替代方案，用于提升饮用水水质。