title: Plasma-induced reduction of chromium(VI) in an aqueous solution.
abstract: An efficient reduction of hexavalent chromium [Cr(VI)] induced by gaseous glow discharge plasma (GDP) generated between a pointed platinum anode and the surface of an aqueous solution has been achieved for the first time. Experimental results show that Cr(VI) could be smoothly reduced to trivalent state [Cr(III)] by using GDP with 500 V as the optimum operating voltage. The rate of Cr(VI) reduction was enhanced by either decreasing the solution pH or adding radical scavengers to the solution. At initial pH 2.0, 100 mg/L of Cr(VI) was completely reduced within 10 min of GDP treatment in the presence of 100 mg/L phenol. A possible reaction mechanism was proposed based on the reduction kinetics. Energy efficiency of Cr(VI) reduction in GDP was compared with that in other competitive processes.
authors.affiliation: Department of Chemistry, Zhejiang University, Hangzhou 310027, PR. China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Xuanzhen
authors.initials: X
authors.lastname: Jiang
mesh_terms: D002274:Carcinogens, Environmental / Q000737:chemistry*; D002857:Chromium / Q000737:chemistry*; D004563:Electrochemistry; D016166:Free Radical Scavengers / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D010084:Oxidation-Reduction; D014867:Water / Q000737:chemistry*
chemical_list: D002274:Carcinogens, Environmental; D016166:Free Radical Scavengers; D014867:Water; D002857:Chromium; C074702:chromium hexavalent ion