Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore 117576.
Eastman Chemical Company, P.O. Box 1972, Kingsport, TN 37662, USA.
Water Res. 2015 Sep 15;81:54-63. doi: 10.1016/j.watres.2015.05.048. Epub 2015 May 27.
By using a novel hydrophilic cellulose acetate butyrate (CAB) as the membrane material for the hollow fiber substrate and modifying its outer surface by polydopamine (PDA) coating and inner surface by interfacial polymerization, we have demonstrated that the thin-film composite (TFC) membranes can be effectively used for sustainable water reclamation from emulsified oil/water streams via forward osmosis (FO) under the pressure retarded osmosis (PRO) mode. The newly developed TFC-FO hollow fiber membrane shows characteristics of high water flux, outstanding salt and oil rejection, and low fouling propensity. Under the PRO mode, the newly developed TFC-FO membrane exhibits a water flux of 37.1 L m(-2) h(-1) with an oil rejection of 99.9% using a 2000 ppm soybean oil/water emulsion as the feed and 1 M NaCl as the draw solution. Remarkable anti-fouling behaviors have also been observed. Under the PRO mode, the water flux decline is only 10% of the initial value even after a 12 h test for oil/water separation. The water flux of the fouled membrane can be effectively restored to 97% of the original value by water rinses on the fiber outer surface without using any chemicals. Furthermore, the flux declines are only 25% and 52% when the water recovery of a 2000 ppm soybean oil/water emulsion and a 2000 ppm petroleum oil/water emulsion containing 0.04 M NaCl reaches 82%, respectively. This study may not only provide insightful guidelines for the fabrication of effective TFC-FO membranes with high performance and low fouling behaviors for oily wastewater under the PRO mode but also add an alternative perspective to the design of new materials for water purification purposes.
通过使用新型亲水性醋酸丁酸纤维素（CAB）作为中空纤维基底的膜材料，并通过聚多巴胺（PDA）涂层修饰其外表面和界面聚合修饰内表面，我们证明了薄膜复合（TFC）膜可以在压力延迟渗透（PRO）模式下通过正向渗透（FO）有效地用于从乳化油/水混合物中可持续地回收水。新开发的 TFC-FO 中空纤维膜具有高水通量、出色的盐和油排斥以及低污染倾向的特点。在 PRO 模式下，使用 2000ppm 的大豆油/水乳液作为进料和 1M NaCl 作为汲取液，新开发的 TFC-FO 膜的水通量为 37.1L/m²h，油排斥率为 99.9%。还观察到了显著的抗污染行为。在 PRO 模式下，即使在 12 小时的油水分离测试后，水通量下降仅为初始值的 10%。通过在纤维外表面用水冲洗，可以将污染膜的水通量有效地恢复到原始值的 97%，而无需使用任何化学品。此外，当 2000ppm 大豆油/水乳液和含 0.04M NaCl 的 2000ppm 石油油/水乳液的水回收率分别达到 82%时，通量下降仅为 25%和 52%。这项研究不仅为在 PRO 模式下制造具有高性能和低污染行为的有效 TFC-FO 膜提供了有见地的指导，而且为用于水净化目的的新材料设计提供了另一种视角。
