用于处理水中微污染物的TiO2/聚合物/氧化石墨烯复合膜的设计、组装与降解和渗透机理研究

Micropollutants are widely distributed in the water environment, which are difficult to degrade, persistant and bioaccumulation. These kinds of pollutants are difficult to be treated by conventional water purification process, while the membrane separation process can effectively remove micropollutants in water. This study intends to use two-dimensional material graphene oxide nanosheets as skeleton material of membrane separation layer, stacked to form unique nano permeability channel with high flux and high rejection performance. Introducing the high energy crystal surface TiO2 into graphene oxide membrane can significantly enhance the photocatalytic effect and antifouling property. The polymer with special group and chain segment is introduced to improve the structural stability of the membrane, optimize the permeation channel, and provide the environmental response function.Then TiO2/polymer/graphene oxide composite membrane is prepared by coupling the above methods to treat micropollutants in water. Through the experiment of membrane filtration and theoretical simulation and analysis, the mechanism of photocatalytic degradation and permeation of graphene oxide composite membrane is revealed. Finally, the preparation method and water treatment process of TiO2/polymer/graphene oxide composite membrane are established, which laid the theoretical and practical foundation for the large-scale application of graphene oxide composite membrane.

微污染物在水体中分布广泛，具有难降解、持久性和生物富集等特性，严重危害人类的健康。此类物质难以用常规工艺去除，而膜分离工艺能有效去除水中微污染物。本课题拟采用二维材料氧化石墨烯纳米片作为膜分离层的骨架材料，堆叠形成独特的纳米渗透通道，使膜具备高通量和高截留性能；引入暴露高能晶面TiO2，与氧化石墨烯形成增强的光催化体系，提高分离膜的光催化效应和抗污染性能；引入含特殊基团和链段的聚合物，提高膜的结构稳定性，优化渗透通道，并提供环境响应功能；耦合以上多种手段制备TiO2/聚合物/氧化石墨烯复合膜，用于水中微污染物的处理；通过膜过滤实验和理论模拟计算与分析，揭示氧化石墨烯复合膜的光催化降解和渗透机理。最后建立TiO2/聚合物/氧化石墨烯复合膜制备方法和水处理工艺，为推动氧化石墨烯复合膜的大规模应用奠定理论和实践基础。

膜分离技术是以具有选择透过性能的膜为工作核心，在外界能量的驱动下，对废水中的污染物进行过滤，是高效的废水处理和循环利用技术。二维材料氧化石墨烯纳米片具有最薄的单原子厚度，并且带有丰富的官能团，本课题以其作为膜分离层的改性材料，通过引入含特殊基团改变聚合物膜的孔径分布和膜表面性质，提高膜的通量和截留率。利用氧化石墨烯作为纳滤膜分离层的骨架材料，通过调节纳米通道和膜表面电荷等策略制备具有高选择透过性的纳滤膜，实现染料/盐以及一价/二价盐的高效分离，对含盐染料废水的资源化利用和零排放具有重要意义。