title: Remediation of antimony-rich mine waters: Assessment of antimony removal and shifts in the microbial community of an onsite field-scale bioreactor.
abstract: An on-site field-scale bioreactor for passive treatment of antimony (Sb) contamination was installed downstream of an active Sb mine in Southwest China, and operated for one year (including a six month monitoring period). This bioreactor consisted of five treatment units, including one pre-aerobic cell, two aerobic cells, and two microaerobic cells. With the aerobic cells inoculated with indigenous mine water microflora, the bioreactor removed more than 90% of total soluble Sb and 80% of soluble antimonite (Sb(III)). An increase in pH and decrease of oxidation-reduction potential (Eh) was also observed along the flow direction. High-throughput sequencing of the small subunit ribosomal RNA (SSU rRNA) gene variable (V4) region revealed that taxonomically diverse microbial communities developed in the bioreactor. Metal (loid)-oxidizing bacteria including Ferrovum, Thiomonas, Gallionella, and Leptospirillum, were highly enriched in the bioreactor cells where the highest total Sb and Sb(III) removal occurred. Canonical correspondence analysis (CCA) indicated that a suite of in situ physicochemical parameters including pH and Eh were substantially correlated with the overall microbial communities. Based on an UPGMA (Unweighted Pair Group Method with Arithmetic Mean) tree and PCoA (Principal Coordinates Analysis), the microbial composition of each cell was distinct, indicating these in situ physicochemical parameters had an effect in shaping the indigenous microbial communities. Overall, this study was the first to employ a field-scale bioreactor to treat Sb-rich mine water onsite and, moreover, the findings suggest the feasibility of the bioreactor in removing elevated Sb from mine waters.
authors.affiliation: State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China; Guangdong Institute of Eco-environment and Soil Sciences, Guangzhou, 510650, China; Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ, 08901, USA.
authors.forename: Weimin
authors.initials: W
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Enzong
authors.initials: E
authors.lastname: Xiao
authors.affiliation: Boojum Research Ltd., Toronto, Ontario, M4T 1L9, Canada.
authors.forename: Margarete
authors.initials: M
authors.lastname: Kalin
authors.affiliation: Department of Environmental Sciences, Rutgers University, New Brunswick, NJ, 08901, USA.
authors.forename: Valdis
authors.initials: V
authors.lastname: Krumins
authors.affiliation: Department of Geology, University of Illinois-Urbana Champaign, Urbana, IL, 61801, USA.
authors.forename: Yiran
authors.initials: Y
authors.lastname: Dong
authors.affiliation: State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China.
authors.forename: Zengping
authors.initials: Z
authors.lastname: Ning
authors.affiliation: Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ, 08901, USA.
authors.forename: Tong
authors.initials: T
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Min
authors.initials: M
authors.lastname: Sun
authors.affiliation: Water Resources Protection Bureau of Pearl River Water Resources Commission, Guangzhou, 510611, China.
authors.forename: Yanlong
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Water Resources Protection Bureau of Pearl River Water Resources Commission, Guangzhou, 510611, China.
authors.forename: Shiliang
authors.initials: S
authors.lastname: Wu
authors.affiliation: Yunnan Provincial Bureau of Hydrology and Water Resources, Kunming 650106, China.
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Mao
authors.affiliation: State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China. Electronic address: xiaotangfu@vip.gyig.ac.cn.
authors.forename: Tangfu
authors.initials: T
authors.lastname: Xiao
mesh_terms: D000965:Antimony / Q000032:analysis*; D001419:Bacteria; D001673:Biodegradation, Environmental; D019149:Bioreactors; D002681:China; D052918:Environmental Restoration and Remediation / Q000379:methods*; D008906:Mining; D062065:Wastewater / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D000965:Antimony; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Fe-oxidizing bacteria; High-throughput sequencing; In situ bioremediation