title: Arsenite oxidation and removal driven by a bio-electro-Fenton process under neutral pH conditions.
abstract: The iron-catalyzed oxidation of arsenite (As(III)) associated with Fenton or Fenton-like reactions is one of the most efficient arsenic removal methods. However, the conventional chemical or electro-Fenton systems for the oxidation of As(III) are only efficient under acid conditions. In the present study, a cost-effective and efficient bio-electro-Fenton process was performed for As(III) oxidation in a dual-chamber microbial fuel cell (MFC) under neutral pH conditions. In such a system, the Fenton reagents, including H2O2 and Fe(II), were generated in situ by microbial-driven electro-reduction of O2 and γ-FeOOH, respectively, without an electricity supply. The results indicated that the process was capable of inducing As(III) oxidation with an apparent As(III) depletion first-order rate constant of 0.208 h(-1). The apparent oxidation current efficiency was calculated to be as high as 73.1%. The γ-FeOOH dosage in the cathode was an important factor in determining the system performance. Fourier-transform infrared spectroscopy (FT-IR) analysis indicated that As(V) was bound to the solid surface as a surface complex but not as a precipitated solid phase. The mechanism of bio-E-Fenton reaction for As(III) oxidation was also proposed. The bio-electro-Fenton system makes it potentially attractive method for the detoxification of As(III) from aqueous solution.
authors.affiliation: Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, No. 808 Tianyuan Road, Tianhe Dis, Guangzhou 510650, PR China.
authors.forename: Xiang-Qin
authors.initials: XQ
authors.lastname: Wang
authors.affiliation: Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, No. 808 Tianyuan Road, Tianhe Dis, Guangzhou 510650, PR China. Electronic address: cpliu@soil.gd.cn.
authors.forename: Chuan-Ping
authors.initials: CP
authors.lastname: Liu
authors.affiliation: Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, No. 808 Tianyuan Road, Tianhe Dis, Guangzhou 510650, PR China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Yuan
authors.affiliation: Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, No. 808 Tianyuan Road, Tianhe Dis, Guangzhou 510650, PR China. Electronic address: cefbli@soil.gd.cn.
authors.forename: Fang-bai
authors.initials: FB
authors.lastname: Li
mesh_terms: D018053:Arsenites / Q000737:chemistry*; D001674:Bioelectric Energy Sources; D005290:Ferric Compounds / Q000737:chemistry* / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry; D010084:Oxidation-Reduction; D020614:Shewanella putrefaciens / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D018053:Arsenites; D005290:Ferric Compounds; D014874:Water Pollutants, Chemical; C000499:ferric oxide; D006861:Hydrogen Peroxide; D007501:Iron; C015001:arsenite
keywords: Arsenic; Bio-electro-Fenton process; Microbial fuel cell; Oxidation; γ-FeOOH