title: Reduction and removal of aqueous Cr(VI) by glow discharge plasma at the gas-solution interface.
abstract: Aqueous chromium(VI) reduction and removal induced by glow discharge taking place at the gas-solution interface in an argon atmosphere was studied. The effect of initial pH and hydroxyl radical scavenger (ethanol) on the reduction efficiency was examined. High reduction efficiency was obtained when initial pH ≤ 2.0 or ≥ 8.0. In particular, addition of ethanol into the solution substantially increased the reduction efficiency and facilitated chromium removal from the solution in the form of sediment after discharge. The optimum pH values for Cr(VI) removal were within 6.0-7.0. Fourier transform-infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analysis confirmed that the main constituent of the sediment is chromium hydroxide.
authors.affiliation: Key Laboratory of Ion Beam Bio-Engineering, Institute of Biotechnology and Agriculture Engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Ke
authors.forename: Qing
authors.initials: Q
authors.lastname: Huang
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.forename: Zengliang
authors.initials: Z
authors.lastname: Yu
mesh_terms: D011232:Chemical Precipitation; D002857:Chromium / Q000032:analysis / Q000737:chemistry*; D004560:Electricity; D000431:Ethanol / Q000737:chemistry*; D005740:Gases; D006861:Hydrogen Peroxide / Q000032:analysis / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D017665:Hydroxyl Radical / Q000737:chemistry; D009566:Nitrates / Q000032:analysis; D010084:Oxidation-Reduction; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D014865:Waste Disposal, Fluid / Q000379:methods; D018508:Water Purification / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D005740:Gases; D009566:Nitrates; D012996:Solutions; D002857:Chromium; C074702:chromium hexavalent ion; D017665:Hydroxyl Radical; D000431:Ethanol; D006861:Hydrogen Peroxide