title: Adsorptive removal of arsenic from water by an iron-zirconium binary oxide adsorbent.
abstract: Arsenate and arsenite may exist simultaneously in groundwater and have led to a greater risk to human health. In this study, an iron-zirconium (Fe-Zr) binary oxide adsorbent for both arsenate and arsenite removal was prepared by a coprecipitation method. The adsorbent was amorphous with a specific surface area of 339 m(2)/g. It was effective for both As(V) and As(III) removal; the maximum adsorption capacities were 46.1 and 120.0 mg/g at pH 7.0, respectively, much higher than for many reported adsorbents. Both As(V) and As(III) adsorption occurred rapidly and achieved equilibrium within 25 h, which were well fitted by the pseudo-second-order equation. Competitive anions hindered the sorption according to the sequence PO(4)(3-)>SiO(3)(2-)>CO(3)(2-)>SO(4)(2-). The ionic strength effect experiment, measurement of zeta potential, and FTIR study indicate that As(V) forms inner-sphere surface complexes, while As(III) forms both inner- and outer-sphere surface complexes at the water/Fe-Zr binary oxide interface. The high uptake capability and good stability of the Fe-Zr binary oxide make it a potentially attractive adsorbent for the removal of both As(V) and As(III) from water.
authors: Key Laboratory of Coastal Environment Processes, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Laishan District, Yantai, China.
authors: Zongming
authors: Z
authors: Ren
authors: Gaosheng
authors: G
authors: Zhang
authors: J Paul
authors: JP
authors: Chen
mesh_terms: D000327:Adsorption; D001149:Arsenates / Q000302:isolation & purification; D001151:Arsenic / Q000302:isolation & purification*; D018053:Arsenites / Q000302:isolation & purification; D005290:Ferric Compounds / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009994:Osmolar Concentration; D017550:Spectroscopy, Fourier Transform Infrared; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification; D018508:Water Purification / Q000191:economics / Q000379:methods*; D015040:Zirconium / Q000737:chemistry*
chemical_list: D001149:Arsenates; D018053:Arsenites; D005290:Ferric Compounds; D014874:Water Pollutants, Chemical; D014867:Water; C000499:ferric oxide; D015040:Zirconium; C015001:arsenite; D001151:Arsenic; C025657:arsenic acid; C028541:zirconium oxide