正渗透技术研究现状及进展

作为一种新型膜处理技术,正渗透技术自20世纪50年代建立以来,在环保、能源、海水淡化等领域受到越来越广泛的关注;其经历了从实验室研究,中试实验,到少量的商业化应用,技术日臻完善.本文综合了国内外相关文献的信息,从正渗透膜制备、浓差极化、汲取液及正渗透应用等四方面对正渗透技术的研究现状及进展进行了综述,并分析了其应用过程中存在的缺陷和未来发展趋势.正渗透技术的研发虽取得了显著进展,但仍存在应用瓶颈.正渗透膜仍存在对某些污染物的截留率不高、支撑层内浓差极化大、造价较贵等问题;影响浓差极化的因素尽管已经比较清楚,但至今尚无有效大幅度降低甚至消除内浓差极化的方法;汲取液存在反向渗透较重、回收过程能耗较大等问题;正渗透技术的应用范围,特别是在工业废水处理领域还需拓展.

The current status and research advances in forward osmosis

As a novel membrane technology, forward osmosis (FO) is attracting increasing attention in the field of environmental protection, energy sources exploration, seawater desalination, etc. The study on FO has experienced laboratory scale experiments, pilot-scale studies and very a few of commercial applications, which facilitates the progress of FO technology. Based on the literatures, this review attempts to summarize the research progress in FO membrane fabrication, concentration polarization identification, draw solution selection and the application of FO. Besides, the existed problems in the application and the future development trend are also analyzed. In summary, there has been great progress in the study of FO, but there is still bottleneck for its application. The current available FO membranes still have some problems, such as low rejection to some pollutants, heavy concentration polarization in the support layer and high cost. Factors affecting the concentration polarization are clear, but so far, there lacks effective methods to reduce or even eliminate the internal concentration polarization. As for draw solution, it is need to develop methods to reduce the solute reverse osmosis and energy consumption for its recycling. In addition, applications of FO in the field of industrial wastewater treatment still need to be explored.