title: Zirconium/polyvinyl alcohol modified flat-sheet polyvinyldene fluoride membrane for decontamination of arsenic: Material design and optimization, study of mechanisms, and application prospects.
abstract: Arsenic contamination in industrial wastewater and groundwater has become an important environmental issue. In this study, a novel zirconium/polyvinyl alcohol (PVA) modified polyvinyldene fluoride (PVDF) membrane was developed for arsenate removal from simulated contaminated water. A PVDF flat-sheet membrane was first fabricated; it was then soaked in a zirconium-PVA solution and dried, and finally reacted with a glutaraldehyde solution, by which the zirconium ions were impregnated onto the PVDF surface through the ether and hydroxyl groups according to the cross-linkage mechanism. The fabrication procedure was optimized by the Box-Behnken experimental design approach. The adsorption kinetics study showed that most of uptake occurred in 5 h and the equilibrium was established in 24 h. The acidic condition was beneficial for the arsenate removal and the optimal removal efficiency can be obtained at pH 2.0. The experimental data of the adsorption isotherm was better described by Langmuir equation than Freundlich equation. The maximum adsorption capacity of 128 mg-As/g was achieved at pH 2.0. In the filtration study, the modified membrane with an area of 12.56 cm(2) could treat 15.6 L arsenate solution (equivalent to 75,150 bed volumes) with an influent concentration of 98.6 μg/L to meet the maximum contaminate level of 10 μg/L. Several instrumental studies revealed that the removal was mainly associated with ion exchange between chloride and arsenate ions.
authors.affiliation: Department of Civil and Environmental Engineering, National University of Singapore, 10 Kent Ridge Crescent, 119260, Singapore.
authors.forename: Dandan
authors.initials: D
authors.lastname: Zhao
authors.affiliation: Department of Civil and Environmental Engineering, National University of Singapore, 10 Kent Ridge Crescent, 119260, Singapore.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Department of Civil and Environmental Engineering, National University of Singapore, 10 Kent Ridge Crescent, 119260, Singapore. Electronic address: paulchen@nus.edu.sg.
authors.forename: J Paul
authors.initials: JP
authors.lastname: Chen
mesh_terms: D000327:Adsorption; D001149:Arsenates / Q000737:chemistry*; D001151:Arsenic / Q000032:analysis / Q000737:chemistry*; D002712:Chlorides / Q000737:chemistry; D003666:Decontamination / Q000379:methods*; D005374:Filtration / Q000295:instrumentation / Q000379:methods*; D060587:Groundwater; D006863:Hydrogen-Ion Concentration; D007474:Ion Exchange; D007700:Kinetics; D011142:Polyvinyl Alcohol / Q000737:chemistry; D011145:Polyvinyls / Q000737:chemistry*; D062065:Wastewater; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*; D015040:Zirconium / Q000737:chemistry*; D005465:Fluorocarbon Polymers
chemical_list: D001149:Arsenates; D001151:Arsenic; D002712:Chlorides; D011142:Polyvinyl Alcohol; D011145:Polyvinyls; D062065:Wastewater; D014874:Water Pollutants, Chemical; D015040:Zirconium; C024865:polyvinylidene fluoride; D005465:Fluorocarbon Polymers
keywords: Arsenate; Chloride; Filtration; Ion exchange; Removal; Zirconium/PVA modified PVDF membrane