银纳米线复合静电纺丝膜终端饮用水处理装置电化学消毒效能研究

Electrochemical disinfection performance of a point-of-use drinking water treatment device constructed with silver nanowires composite electrospun membrane

终端饮用水电化学消毒装置是分散式饮用水安全的重要保障,其关键技术是过滤膜.本研究采用静电纺丝法和真空过滤沉积法制备了新型银纳米线-聚丙烯腈/热塑性聚氨酯(AgNWs-PAN/TPU)复合膜,并对复合膜的形貌、机械强度和导电性等进行了表征.同时,构建了电化学消毒装置,通过对模拟水样的过滤和电化学消毒实验,考察了复合膜长期运行的杀菌性能、膜通量、膜形貌及总银离子释放变化,评估了复合膜的消毒效果.结果表明,电纺纳米纤维膜基材具有均匀的直径和增强的机械性能.银纳米线嵌入到PAN/TPU电纺纳米纤维膜的表面构建了一个连接的导电网络,具有很好的机械性能、导电性、电化学性能及银负载稳定性.经过10 d的自来水过滤实验,AgNWs-PAN/TPU复合膜膜通量下降了4.8%,保持了>99.99%的灭菌效率;经过10 d的10~5CFU·mL^(-1)大肠杆菌水样运行实验,膜通量下降了35.31%,经5 min反冲洗能够恢复98%的膜通量,可保留99%以上的细菌灭活效率.AgNWs-PAN/TPU复合膜的银负载稳定性好,总银离子释放量在30μg·L^(-1)以下的安全范围;纳米纤维膜表面在长期水力冲刷下变得粗糙,机械强度略有减弱.本研究为高导电性缓释银离子纳米银复合纤维膜杀菌材料的研发及其在终端饮用水消毒的应用提供了科学依据.

Point-of-use drinking water treatment device plays an important role in decentralized drinking water safety,in which the the filter membrane is a key factor. In this study,a novel silver nanowires-polyacrylonitrile/thermoplastic polyurethane（ AgNWs-PAN/TPU） composite membrane was fabricated through electrospinning and vacuum filtration deposition. The morphology,mechanical strength and electrical conductivity of the composite membrane were characterized. A point-of-use drinking water treatment device was constructed with the membrane and the long-term electrochemical disinfection performance was evaluated by inactivation efficiency,flux,membrane morphology and total silver release. SEM and DMA results show that AgNWs-PAN/TPU membrane fiber had uniform diameters and enhanced mechanical properties. A highly conductive,good physical stability and low silver ions leaching network was constructed by AgNWs. After 10 days of simulated operation,the flux of AgNWs-PAN/TPU membrane decreased by 4. 8% in tap water environment and the inactivation efficiency maintained 99.99%. In 105 CFU·mL-1 Escherichia coli environment,the flux decreased by 35.31%,andrecovered to 98% after a 5 min backwash; the inactivation efficiency retained more than 99%. The silver loading of the membrane was stable,with the total silver release below 30 μg·L-1 which was safe to drink. The surface of membrane nanofibers became rough under long time hydraulic erosion,and the mechanical strength was slightly declined. This study provides a scientific basis for the research and development of highly conductive silver composite membranes and their application in point-of-use drinking water disinfection.