NUS Graduate School for Integrative Science and Engineering, National University of Singapore , Singapore 117456.
Department of Chemical and Biomolecular Engineering, National University of Singapore , Singapore 117585.
Environ Sci Technol. 2016 Jul 19;50(14):7696-705. doi: 10.1021/acs.est.5b06166. Epub 2016 Jun 23.
Boron removal is one of the great challenges in modern wastewater treatment, owing to the unique small size and fast diffusion rate of neutral boric acid molecules. As forward osmosis (FO) membranes with a single selective layer are insufficient to reject boron, double-skinned FO membranes with boron rejection up to 83.9% were specially designed for boron permeation studies. The superior boron rejection properties of double-skinned FO membranes were demonstrated by theoretical calculations, and verified by experiments. The double-skinned FO membrane was fabricated using a sulfonated polyphenylenesulfone (sPPSU) polymer as the hydrophilic substrate and polyamide as the selective layer material via interfacial polymerization on top and bottom surfaces. A strong agreement between experimental data and modeling results validates the membrane design and confirms the success of model prediction. The effects of key parameters on boron rejection, such as boron permeability of both selective layers and structure parameter, were also investigated in-depth with the mathematical modeling. This study may provide insights not only for boron removal from wastewater, but also open up the design of next generation FO membranes to eliminate low-rejection molecules in wider applications.
硼的去除是现代废水处理的一大挑战，这是由于中性硼酸分子的独特小尺寸和快速扩散率所致。由于具有单层选择性层的正向渗透 (FO) 膜不足以去除硼，因此特别设计了硼截留率高达 83.9%的双皮层 FO 膜来进行硼渗透研究。通过理论计算和实验验证，证明了双皮层 FO 膜具有优异的硼截留性能。双皮层 FO 膜是通过在顶部和底部表面的界面聚合，使用磺化聚苯砜 (sPPSU) 聚合物作为亲水性基底和聚酰胺作为选择性层材料来制造的。实验数据与模型结果之间具有很强的一致性，验证了膜的设计，并确认了模型预测的成功。还通过数学建模深入研究了关键参数对硼截留的影响，例如选择性层的硼渗透率和结构参数。这项研究不仅可为从废水中去除硼提供启示，而且还为下一代 FO 膜的设计开辟了道路，以在更广泛的应用中消除低截留分子。
