Experiments and Modeling of Boric Acid Permeation through Double-Skinned Forward Osmosis Membranes.
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.
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.
Lin
L
Luo
School of Chemistry & Chemical Engineering, Jiangsu University , 301 Xuefu Road, Zhenjiang, Jiangsu Province, P. R. China 212013.
Zhengzhong
Z
Zhou
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.
Tai-Shung
TS
Chung
Advanced Materials & Systems Research, BASF SE, GM-B001, 67056 Ludwigshafen, Germany.
Martin
M
Weber
Advanced Materials & Systems Research, BASF SE, GM-B001, 67056 Ludwigshafen, Germany.
Claudia
C
Staudt
Performance Materials, BASF SE, G-PM/PU-F206, 67056 Ludwigshafen, Germany.
Christian
C
Maletzko
D001888:Boric Acids; D008567:Membranes, Artificial; D009995:Osmosis; D010539:Permeability; D018508:Water Purification
D001888:Boric Acids; D008567:Membranes, Artificial