title: Effective As(III) Removal by A Multi-Charged Hydroacid Complex Draw Solute Facilitated Forward Osmosis-Membrane Distillation (FO-MD) Processes.
abstract: Effective removal of As(III) from water by an oxalic acid complex with the formula of Na3[Cr(C2O4)3] (Na-Cr-OA) is demonstrated via an forward osmosis-membrane distillation (FO-MD) hybrid system in this study. Na-Cr-OA first proved its superiority as a draw solute with high water fluxes and negligible reverse fluxes in FO, then a systematic investigation of the Na-Cr-OA promoted FO process was conducted to ascertain the factors in As(III) removal. Relatively high water fluxes of 28 LMH under the FO mode and 74 LMH under the pressure retarded osmosis (PRO) mode were achieved when using a 1000 ppm As(III) solution as the feed and 1.0 M Na-Cr-OA as the draw solution at 60 °C. As(III) removal with a water recovery up to 21.6% (FO mode) and 48.3% (PRO mode) were also achieved in 2 h. An outstanding As(III) rejection with 30-3000 μg/L As(III) in the permeate was accomplished when As(III) feed solutions varied from 5 × 10(4) to 1 × 10(6) μg/L, superior to the best FO performance reported for As(III) removal. Incorporating MD into FO not only makes As(III) removal sustainable by reconcentrating the Na-Cr-OA solution simultaneously, but also reduces the As(III) concentration below 10 μg/L in the product water, meeting the WHO standard.
authors.affiliation: College of Environment and Resources, Fuzhou University , Fujian 350116, China.
authors.forename: Qingchun
authors.initials: Q
authors.lastname: Ge
authors.affiliation: Department of Chemical & Biomolecular Engineering, National University of Singapore , 4 Engineering Drive 4, Singapore 117576, Singapore.
authors.forename: Gang
authors.initials: G
authors.lastname: Han
authors.affiliation: Department of Chemical & Biomolecular Engineering, National University of Singapore , 4 Engineering Drive 4, Singapore 117576, Singapore.|Water Desalination & Reuse (WDR) Center King Abdullah University of Science and Technology , Thuwal, Saudi Arabia 23955-6900.
authors.forename: Tai-Shung
authors.initials: TS
authors.lastname: Chung
mesh_terms: D001151:Arsenic / Q000302:isolation & purification*; D057168:Distillation / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D008567:Membranes, Artificial; D009995:Osmosis; D019815:Oxalic Acid / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D012996:Solutions; D013450:Sulfones / Q000737:chemistry; D013696:Temperature; D014783:Viscosity; D018508:Water Purification / Q000379:methods*
chemical_list: D008567:Membranes, Artificial; D011108:Polymers; D012996:Solutions; D013450:Sulfones; C022840:polyether sulfone; D019815:Oxalic Acid; D001151:Arsenic