title: Stimulation of Fe(II) Oxidation, Biogenic Lepidocrocite Formation, and Arsenic Immobilization by Pseudogulbenkiania Sp. Strain 2002.
abstract: An anaerobic nitrate-reducing Fe(II)-oxidizing bacterium, Pseudogulbenkiania sp. strain 2002, was used to investigate As immobilization by biogenic Fe oxyhydroxides under different initial molar ratios of Fe/As in solutions. Results showed that Fe(II) was effectively oxidized, mainly forming lepidocrocite, which immobilized more As(III) than As(V) without changing the redox state of As. When the initial Fe/As ratios were kept constant, higher initial Fe(II) concentrations immobilized more As with higher Asimmobilized/Feprecipitated in biogenic lepidocrocite. EXAFS analysis showed that variations of initial Fe(II) concentrations did not change the As-Fe complexes (bidentate binuclear complexes ((2)C)) with a fixed As(III) or As(V) initial concentration of 13.3 μM. On the other hand, variations in initial As concentrations but fixed Fe(II) initial concentration induced the co-occurrence of bidentate binuclear and bidentate mononuclear complexes ((2)E) and bidentate binuclear and monodentate mononuclear complexes ((1)V) for As(III) and As(V)-treated series, respectively. The coexistence of (2)C and (2)E complexes (or (2)C and (1)V complexes) could contribute to higher As removal in experimental series with higher initial Fe(II) concentrations at the same initial Fe/As ratio. Simultaneous removal of soluble As and nitrate by anaerobic nitrate-reducing Fe(II)-oxidizing bacteria provides a feasible approach for in situ remediation of As-nitrate cocontaminated groundwater.
authors.affiliation: State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences , Beijing 100083, P.R. China.|School of Water Resources and Environment, China University of Geosciences , Beijing 100083, P.R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Xiu
authors.affiliation: State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences , Beijing 100083, P.R. China.|School of Water Resources and Environment, China University of Geosciences , Beijing 100083, P.R. China.
authors.forename: Huaming
authors.initials: H
authors.lastname: Guo
authors.affiliation: School of Water Resources and Environment, China University of Geosciences , Beijing 100083, P.R. China.
authors.forename: Jiaxing
authors.initials: J
authors.lastname: Shen
authors.affiliation: School of Water Resources and Environment, China University of Geosciences , Beijing 100083, P.R. China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Liu
authors.affiliation: School of Water Resources and Environment, China University of Geosciences , Beijing 100083, P.R. China.
authors.forename: Susu
authors.initials: S
authors.lastname: Ding
authors.affiliation: State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences , Beijing 100083, P.R. China.
authors.forename: Weiguo
authors.initials: W
authors.lastname: Hou
authors.affiliation: School of Water Resources and Environment, China University of Geosciences , Beijing 100083, P.R. China.
authors.forename: Jie
authors.initials: J
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences , Beijing 100083, P.R. China.
authors.forename: Hailiang
authors.initials: H
authors.lastname: Dong
mesh_terms: D001151:Arsenic; D005296:Ferrous Compounds; D060587:Groundwater; D009566:Nitrates; D010084:Oxidation-Reduction
chemical_list: D005296:Ferrous Compounds; D009566:Nitrates; D001151:Arsenic