title: Spherical polystyrene-supported nano-Fe3O4 of high capacity and low-field separation for arsenate removal from water.
abstract: Fe(3)O(4) is a promising material for arsenic sequestration due to its specific affinity toward arsenic and feasible magnetic separation. How to further increase its adsorption capacity while maintain its low-field separation is an interesting but challenging task. In this study nano-Fe(3)O(4) was successfully coated onto the outer surface of polystyrene (PS) beads of 350-400 nm in diameter by the hetero-coacervation method, and the resulting composite PS-Fe(3)O(4) was characterized using transmission electron microscope (TEM), X-ray powder diffraction (XRD), and electrophoresis measurement (EM). Its adsorption toward arsenate was investigated as a function of solution pH, arsenic concentration, contact time, and coexisting anions. The maximum adsorption capacity of PS-Fe(3)O(4) was 139.3mg/g Fe(3)O(4), 77.7% greater than that of bulky Fe(3)O(4). More attractively, it can be readily separated from water under a low magnetic field (<0.035 T). Continuous adsorption-desorption cyclic results demonstrated that arsenate-loaded PS-Fe(3)O(4) can be effectively regenerated by NaOH solution, and the regenerated composite beads could be employed for repeated use without significant capacity loss, indicating that nano-Fe(3)O(4) was steadily coated onto the surface of PS beads. Generally, PS beads could be employed as a promising host to fabricate efficient composites originated from Fe(3)O(4) or other nanoparticles for environmental remediation.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Xianlin Campus, Nanjing University, Nanjing 210023, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Jiang
authors.forename: Xubin
authors.initials: X
authors.lastname: Chen
authors.forename: Yingjie
authors.initials: Y
authors.lastname: Niu
authors.forename: Bingcai
authors.initials: B
authors.lastname: Pan
mesh_terms: D000327:Adsorption; D000465:Algorithms; D001149:Arsenates / Q000302:isolation & purification*; D004574:Electromagnetic Fields; D004655:Emulsions; D052203:Ferrosoferric Oxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry*; D013816:Thermodynamics; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification; D014961:X-Ray Diffraction
chemical_list: D001149:Arsenates; D004655:Emulsions; D011137:Polystyrenes; D014874:Water Pollutants, Chemical; C025657:arsenic acid; D052203:Ferrosoferric Oxide