MXene协同抗污染导电超滤膜的构建及微观性能调控

Membrane bioreactors (MBRs) have been actively employed for municipal and industrial wastewater treatments. However, the increased operation and maintenance costs caused by membrane fouling are the major obstacles for the wider application of MBRs. To alleviate membrane fouling in MBRs, many methods have been investigated, among which electro-assisted MBRs is an option by exposing the membrane to a direct current. In this project, functionalized polymers will be introduced to fabricate conductive ultrafiltration (UF) membrane to reduce membrane resistance. MXene is applied to regulate the membrane properties in the membrane matrix and/or on the membrane surface by taking its advantages like high hydrophilicity, high conductivity and two dimensional structure. With the presence of direct current, negatively charged foulants will move away from membrane surface due to the electric field force. Meantime, functional groups of the membrane can also contribute to suppress the membrane fouling by electro-static repulsion. When the obtained membrane is applied in MBRs application, the effect of direct current on membrane flux, activated sludge properties and COD/NH3 removal efficiencies will be investigated. Further analysis of membrane fouling and separation mechanism will be discussed and the intrinsic connections between membrane structure and the flux or antifouling ability will be revealed. The newly development membrane is expect to overcome the current problems related to membrane fouling and provide some guidelines for the synthesis of conductive UF membrane and the applications of MBRs.

MBRs能够有效提升城市污水与工业污水的处理效果，提高水资源的利用率。然而，膜污染所带来的运行和维护费用的增加限制了其大规模的应用。因此从根本上解决膜污染问题具有十分重要的意义。本项目拟采用带功能基团的高分子聚合物制备导电超滤膜或其基膜，并使用电沉积，真空抽滤，仿生材料改性等方法在膜表面构筑功能层。利用2D MXene的亲水性和导电性，分别从膜基质或膜功能层对膜进行修饰。由于膜基质功能基团的存在，膜面电阻显著降低，利用外加电场对膜表面同价态污染物的迁移作用和功能基团对污染物质的排斥作用来减缓膜污染。在MBRs实际应用中，分析过程中导电膜的抗污染和分离机理，并在保证其长期运行稳定性的基础上，调控膜结构与通量和抗污染能力之间的关系。本项目的研究成果将有助于新型导电超滤膜的开发和形成，同时可为纳米基础上的膜结构优化提供研究基础，具有重要的科学意义。

MBRs能够有效提升城市污水与工业污水的处理效果，提高水资源的利用率。然而，膜污染所带来的运行和维护费用的增加限制了其大规模的应用。因此从根本上解决膜污染问题具有十分重要的意义。本项目利用电场调控膜的污染过程，通过电场作用控制MBR运行过程中荷负电有机颗粒的迁移实现膜表面污染的控制，实现MBR的高效运行。利用MXene的导电性和亲水性，通过不同方式构筑性能优异的分离膜，调控膜的结构和性能，揭示膜的结构和性能的关系，为MBR高效运行提供理论支持。