title: Influence of clay minerals on sorption and bioreduction of arsenic under anoxic conditions.
abstract: Adsorption of As(V) on various clay minerals including kaolinite (KGa-1), montmorillonite (SWy-1) and nontronites (NAU-1 and NAU-2), and subsequent bioreduction of sorbed As(V) to As(III) by bacterium Shewanella putrefaciens strain CN-32 were investigated. Nontronites showed relatively higher sorption capacity for As(V) primarily due to higher iron oxide content. Freundlich equation well described the sorption of As(V) on NAU-1, NAU-2 and SWy-1, while As(V) sorption isotherm with KGa-1 fitted well in the Langmuir model. The bacterium rapidly reduced 50% of dissolved As(V) to As(III) in 2 h, followed by its complete reduction (>ca. 98%) within 12 h. In contrast, sorption of As(V) to the mineral surfaces interferes with the activity of bacterium, resulting in low bioreduction of As(V) by 27% for 5 days of incubation. S. putrefaciens also promoted the reduction of Fe(III) present in the clay mineral to Fe(II). This study indicates that the sorption and subsequent bioreduction of As(V) on clay minerals can significantly influence the mobility of As(V) in subsurface environment.
authors.affiliation: Department of Soil Science, Agricultural College, Ferdowsi University of Mashhad, Mashhad, Islamic Republic of Iran.
authors.forename: Nasrin
authors.initials: N
authors.lastname: Ghorbanzadeh
authors.affiliation: Department of Soil Science, Agricultural College, Ferdowsi University of Mashhad, Mashhad, Islamic Republic of Iran.
authors.forename: Amir
authors.initials: A
authors.lastname: Lakzian
authors.affiliation: Department of Soil Science, Agricultural College, Ferdowsi University of Mashhad, Mashhad, Islamic Republic of Iran.
authors.forename: Akram
authors.initials: A
authors.lastname: Halajnia
authors.affiliation: Department of Natural Resources and Environmental Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 133-791, South Korea.
authors.forename: Akhil N
authors.initials: AN
authors.lastname: Kabra
authors.affiliation: Department of Natural Resources and Environmental Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 133-791, South Korea.
authors.forename: Mayur B
authors.initials: MB
authors.lastname: Kurade
authors.affiliation: Department of Energy and Mineral Resources Engineering, College of Engineering, Dong-A University, 840 Handan2-dong, Saha-gu, Busan, 604-714, South Korea.
authors.forename: Dae S
authors.initials: DS
authors.lastname: Lee
authors.affiliation: Department of Natural Resources and Environmental Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 133-791, South Korea. bhjeon@hanyang.ac.kr.
authors.forename: Byong-Hun
authors.initials: BH
authors.lastname: Jeon
mesh_terms: D000327:Adsorption; D000538:Aluminum Silicates / Q000737:chemistry*; D001151:Arsenic / Q000737:chemistry / Q000378:metabolism*; D001546:Bentonite / Q000737:chemistry; D000077215:Clay; D005290:Ferric Compounds / Q000737:chemistry; D007616:Kaolin / Q000737:chemistry; D010084:Oxidation-Reduction; D020614:Shewanella putrefaciens / Q000378:metabolism*
chemical_list: D000538:Aluminum Silicates; D005290:Ferric Compounds; D001546:Bentonite; C000499:ferric oxide; D007616:Kaolin; D001151:Arsenic; D000077215:Clay
keywords: Adsorption; Arsenic; Bioreduction; Clay minerals; Shewanella putrefaciens