title: Removal of organic micro-pollutants (phenol, aniline and nitrobenzene) via forward osmosis (FO) process: Evaluation of FO as an alternative method to reverse osmosis (RO).
abstract: In this study, we have explored and compared the effectiveness of using (1) lab-fabricated forward osmosis (FO) membranes under both FO and reverse osmosis (RO) modes and (2) commercially available RO membranes under the RO mode for the removal of organic micro-pollutants. The lab-fabricated FO membranes are thin film composite (TFC) membranes consisting of a polyamide layer and a porous substrate cast from three different materials; namely, Matrimid, polyethersulfone (PESU) and sulfonated polyphenylene sulfone (sPPSU). The results show that the FO mode is superior to the RO mode in the removal of phenol, aniline and nitrobenzene from wastewater. The rejections of all three TFC membranes to all the three organic micro-pollutants under the FO processes are higher than 72% and can be even higher than 90% for aniline when a 1000 ppm aromatic aqueous solution and 1 M NaCl are employed as feeds. These performances outperform the results obtained from themselves and commercially available RO membranes under the RO mode. In addition, the rejection can be maintained even when treating a more concentrated feed solution (2000 ppm). The removal performance can be further enhanced by using a more concentrated draw solution (2 M). The water flux is almost doubled, and the rejection increment can reach up to 17%. Moreover, it was observed that annealing as a post-treatment would help compact the membrane selective layer and further enhance the separating efficiency. The obtained organic micro-pollutant rejections and water fluxes under various feasible operating conditions indicate that the FO process has potential to be a viable treatment for wastewater containing organic micro-pollutants.
authors.affiliation: Department of Chemistry, National University of Singapore, 117542, Singapore; Department of Chemical and Biomolecular Engineering, National University of Singapore, 117542, Singapore.
authors.forename: Yue
authors.initials: Y
authors.lastname: Cui
authors.affiliation: Department of Chemistry, National University of Singapore, 117542, Singapore; Department of Physics, National University of Singapore, 117542, Singapore.
authors.forename: Xiang-Yang
authors.initials: XY
authors.lastname: Liu
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore, 117542, Singapore; Water Desalination & Reuse (WDR) Center, King Abdullah University of Science and Technology, 23955-6900, Saudi Arabia. Electronic address: chencts@nus.edu.sg.
authors.forename: Tai-Shung
authors.initials: TS
authors.lastname: Chung
authors.affiliation: Advanced Materials & Systems Research, BASF SE, GM-B001, 67056 Ludwigshafen, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Weber
authors.affiliation: Advanced Materials & Systems Research, BASF SE, GM-B001, 67056 Ludwigshafen, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Staudt
authors.affiliation: Performance Materials, BASF SE, G-PM/PU-F206, 67056 Ludwigshafen, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Maletzko
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D005374:Filtration / Q000379:methods*; D008567:Membranes, Artificial; D009578:Nitrobenzenes / Q000737:chemistry*; D009995:Osmosis; D019800:Phenol / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D000814:Aniline Compounds; D008567:Membranes, Artificial; D009578:Nitrobenzenes; D014874:Water Pollutants, Chemical; D019800:Phenol; C036077:nitrobenzene; C023650:aniline
keywords: Forward osmosis; Removal of organic micro-pollutants; Wastewater treatment