title: Selective oxidation of arsenite by peroxymonosulfate with high utilization efficiency of oxidant.
abstract: Oxidation of arsenite (As(III)) is a critical yet often weak link in many current technologies for remediating contaminated groundwater. We report a novel, efficient oxidation reaction for As(III) conversion to As(V) using commercial available peroxymonosulfate (PMS). As(III) is rapidly oxidized by PMS with a utilization efficiency larger than 90%. Increasing PMS concentrations and pH accelerate oxidation of As(III), independent to the availability of dissolved oxygen. The addition of PMS enables As(III) to oxidize completely to As(V) within 24 h, even in the presence of high concentrations of radical scavengers. On the basis of these observations and theoretical calculations, a two-electron transfer (i.e., oxygen atom transfer) reaction pathway is proposed. Direct oxidation of As(III) by PMS avoids the formation of nonselective reactive radicals, thus minimizing the adverse impact of coexisting organic matter and maximizing the utilization efficiency of PMS. Therefore, this simple approach is considered a cost-effective water treatment method for the oxidation of As(III) to As(V).
authors.affiliation: Southern Cross GeoScience, Southern Cross University , Lismore, NSW 2480, Australia.
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Wang
authors.forename: Richard T
authors.initials: RT
authors.lastname: Bush
authors.forename: Leigh A
authors.initials: LA
authors.lastname: Sullivan
authors.forename: Chuncheng
authors.initials: C
authors.lastname: Chen
authors.forename: Jianshe
authors.initials: J
authors.lastname: Liu
mesh_terms: D018053:Arsenites / Q000737:chemistry*; D004583:Electrons; D016166:Free Radical Scavengers / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007477:Ions; D007501:Iron / Q000737:chemistry; D008751:Methylene Blue / Q000737:chemistry; D016877:Oxidants / Q000737:chemistry*; D010084:Oxidation-Reduction; D010545:Peroxides / Q000737:chemistry*; D012996:Solutions; D013816:Thermodynamics
chemical_list: D018053:Arsenites; D016166:Free Radical Scavengers; D007477:Ions; D016877:Oxidants; D010545:Peroxides; D012996:Solutions; C038288:peroxymonosulfate; D007501:Iron; C015001:arsenite; D008751:Methylene Blue