基于原位汲取全氟辛酸胶束浓差极化层的新型正渗透膜过程

Perfluorooctanoate (PFOA) is a member of perfluoroalkyl surfactants，which has a potential toxicity on human body. Recovery of PFOA can be achieved by pressure-driven membrane process, while during the concentration process, a serious flux decline was observed due to the compaction of PFOA micelles. For the first time, a novel forward osmosis (FO) membrane process based on in-situ drawing concentration polarization layer of surfactant micelles was proposed, and applied in the recovery of concentrated PFOA wastewater. This novel FO process can not only avoid the compaction of PFOA micelles but also in-situ remove the micelles concentration polarization layer, which would control membrane fouling formation and obtain a PFOA solution with super high concentration. In this project, the interaction mechanism between FO membrane and PFOA and its influence on the formation of concentration polarization layer will be clarified. By using mathematical modeling, the formation mechanism of PFOA micelles in the concentration polarization layer on the membrane surface can be revealed. In order to efficiently concentrate and recover PFOA solution using FO membrane, the design and fabrication of FO-drawing membrane module, and the enhancement of concentration polarization peeling process as well as the optimization of concentration polarization removal strategy were systematically investigated. The outcome of this project will not only provide new methodology for the concentrated PFOA wastewater treatment, but also provide new ideas for the FO concentration process.

全氟辛酸是一种全氟烷基表面活性剂，对人体具有潜在危害。利用压力驱动膜过程可实现全氟辛酸的回收，但在浓缩过程中全氟辛酸胶束层的压实会导致膜通量急剧衰减。本项目提出一种基于原位汲取表面活性剂胶束浓差极化层的新型正渗透膜过程，并将其应用于高浓度全氟辛酸废水的回收。新型正渗透膜过程不仅可以避免压力对胶束层的压实，而且可将膜面的胶束浓差极化层实时移出，在控制膜污染的同时可获得高浓度全氟辛酸溶液。本项目将阐明正渗透膜与全氟辛酸间的相互作用机理及其对浓差极化层形成的影响。采用数学模型对膜面浓差极化层进行模拟计算，揭示膜表面浓差极化层内全氟辛酸表面活性剂胶束的形成机制。通过对正渗透-汲取膜组件的设计加工、浓差极化层剥离过程的强化以及浓差极化层移出策略的调控与优化，实现正渗透膜对全氟辛酸的高效浓缩和回收。本项目的顺利实施，不仅为高浓度全氟辛酸废水的处理提供新方法，而且为正渗透膜浓缩过程提供新思路。

全氟辛酸是一种全氟烷基表面活性剂，对人体具有潜在危害。利用压力驱动膜过程可实现全氟辛酸的回收，但在浓缩过程中全氟辛酸胶束层的压实会导致膜通量急剧衰减。本项目提出一种基于原位汲取表面活性剂胶束浓差极化层的新型正渗透膜过程，并将其应用于高浓度全氟辛酸废水的回收。新型正渗透膜过程不仅可以避免压力对胶束层的压实，而且可将膜面的胶束浓差极化层实时移出，在控制膜污染的同时可获得高浓度全氟辛酸溶液。本项目将阐明正渗透膜与全氟辛酸间的相互作用机理及其对浓差极化层形成的影响。采用数学模型对膜面浓差极化层进行模拟计算，揭示膜表面浓差极化层内全氟辛酸表面活性剂胶束的形成机制。通过对正渗透-汲取膜组件的设计加工、浓差极化层剥离过程的强化以及浓差极化层移出策略的调控与优化，实现正渗透膜对全氟辛酸的高效浓缩和回收。不仅为高浓度全氟辛酸废水的处理提供新方法，而且为正渗透膜浓缩过程提供新思路。