Zeng Chenghui, Tanaka Shuhei, Suzuki Yuji, Fujii Shigeo
Graduate School of Engineering, Kyoto University, Yoshida, Sakyo-ku, Kyoto, Japan.
Graduate School of Global Environmental Studies, Kyoto University, Yoshida, Sakyo-ku, Kyoto, Japan.
Chemosphere. 2017 Sep;183:599-604. doi: 10.1016/j.chemosphere.2017.05.132. Epub 2017 May 22.
Nanofiltration was thought to be a good option for the recovery of perfluorohexanoic acid (PFHxA) from industrial wastewater. In this study, two commercially available nanofiltration (NF) membranes (NF 270 and NTR-7450) were tested to concentrate the PFHxA in aqueous solution. Filtration test was conducted in crossflow filtration mode. Membrane flux and PFHxA rejection rate were monitored throughout the filtration test. The impact of initial feed water pH on membrane performance was investigated. Results demonstrated that the two NF membranes showed different response to the change of initial feed water pH, which was caused by the intrinsic properties of membrane material. The flux performance of NF 270 was stable, while its rejection rate of PFHxA was very sensitive to the change of initial feed water pH. Opposite result was obtained with NTR-7450. It had a very good stability on rejection rate, while its flux was very sensitive to the change of initial feed water pH. The mechanisms behind these phenomena were also discussed. The results obtained in this study should be very useful for the process design in practical engineering.
纳滤被认为是从工业废水中回收全氟己酸（PFHxA）的一个不错选择。在本研究中，测试了两种市售纳滤（NF）膜（NF 270和NTR - 7450）对水溶液中PFHxA的浓缩效果。过滤试验采用错流过滤模式进行。在整个过滤试验过程中监测膜通量和PFHxA截留率。研究了初始进水pH对膜性能的影响。结果表明，两种纳滤膜对初始进水pH变化表现出不同的响应，这是由膜材料的固有特性引起的。NF 270的通量性能稳定，而其对PFHxA的截留率对初始进水pH变化非常敏感。NTR - 7450则得到相反的结果。它在截留率方面具有很好的稳定性，而其通量对初始进水pH变化非常敏感。还讨论了这些现象背后的机制。本研究获得的结果对实际工程中的工艺设计应非常有用。
