正渗透过程中汲取质反向渗透研究进展

正渗透(FO)作为一种浓度驱动的膜技术,因其膜污染轻、能耗低和回收率高等优点而逐渐成为膜技术领域的研究热点之一。汲取质的反向渗透是正渗透过程中不可忽视的现象,但其研究相对比较滞后。本文主要介绍了汲取质反渗模型的研究进展,分析了渗透压差、膜表面流速、膜结构与膜材料、温度、汲取质种类、膜取向、离子水力半径等因素对汲取质反向渗透的影响情况,并发现汲取质的反向渗透通量可由其浓度或汲取液渗透压的一元多项式表达。总体而言,FO模式的汲取质反渗模型经过不断发展已相对比较完善,而压力阻尼渗透(PRO)模式的反渗模型则缺陷较大,有待进一步研究;此外,关于汲取质反渗过程影响因素及其影响机制的研究对于汲取质、膜材料的选择与开发,以及正渗透过程的优化均具有重要的指导作用,因此会引起越来越多的关注。

Research progress of reverse draw solute permeation in forward osmosis process

As a concentration-driven membrane process, forward osmosis (FO) is becoming one of the hot spots in the field of membrane technology because of its low fouling, low energy consumption, and high water recovery. Reverse draw solute permeation is a significant phenomenon in FO process, but the research on it is behind other phenomena in FO field. In this paper, the research progress of draw solute reverse osmosis models is reviewed and the effects of such factors as osmosis pressure, membrane surface velocity, membrane structure and materials, solution temperature, draw solute type, membrane orientation, and ionic radius of draw solute on reverse osmosis are analyzed. Draw solute flux can be formulated by a one-dimensional polynomial equation of concentration or osmotic pressure of draw solution. On the whole, the reverse draw solute model of pressure-retarded osmosis (PRO) mode is not as satisfactory as that of FO mode and needs further research. In addition, the research on reverse draw solute permeation is helpful for selecting or developing draw solute and membrane material and optimizing the FO process, so it would attract more and more attention.