title: Treatment of groundwater containing Mn(II), Fe(II), As(III) and Sb(III) by bioaugmented quartz-sand filters.
abstract: High concentrations of iron (Fe(II)) and manganese (Mn(II)) often occur simultaneously in groundwater. Previously, we demonstrated that Fe(II) and Mn(II) could be oxidized to biogenic Fe-Mn oxides (BFMO) via aeration and microbial oxidation, and the formed BFMO could further oxidize and adsorb other pollutants (e.g., arsenic (As(III)) and antimony (Sb(III))). To apply this finding to groundwater remediation, we established four quartz-sand columns for treating groundwater containing Fe(II), Mn(II), As(III), and Sb(III). A Mn-oxidizing bacterium (Pseudomonas sp. QJX-1) was inoculated into two parallel bioaugmented columns. Long-term treatment (120 d) showed that bioaugmentation accelerated the formation of Fe-Mn oxides, resulting in an increase in As and Sb removal. The bioaugmented columns also exhibited higher overall treatment effect and anti-shock load capacity than that of the non-bioaugmented columns. To clarify the causal relationship between the microbial community and treatment effect, we compared the biomass of active bacteria (reverse-transcribed real-time PCR), bacterial community composition (Miseq 16S rRNA sequencing) and community function (metagenomic sequencing) between the bioaugmented and non-bioaugmented columns. Results indicated that the QJX1 strain grew steadily and attached onto the filter material surface in the bioaugmented columns. In general, the inoculated strain did not significantly alter the composition of the indigenous bacterial community, but did improve the relative abundances of xenobiotic metabolism genes and Mn oxidation gene. Thus, bioaugmentation intensified microbial degradation/utilization for the direct removal of pollutants and increased the formation of Fe-Mn oxides for the indirect removal of pollutants. Our study provides an alternative method for the treatment of groundwater containing high Fe(II), Mn(II) and As/Sb.
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Yaohui
authors.initials: Y
authors.lastname: Bai
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Chang
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Jinsong
authors.initials: J
authors.lastname: Liang
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Chen
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. Electronic address: jhqu@rcees.ac.cn.
authors.forename: Jiuhui
authors.initials: J
authors.lastname: Qu
mesh_terms: D005296:Ferrous Compounds; D060587:Groundwater; D011791:Quartz; D012336:RNA, Ribosomal, 16S; D014874:Water Pollutants, Chemical
chemical_list: D005296:Ferrous Compounds; D012336:RNA, Ribosomal, 16S; D014874:Water Pollutants, Chemical; D011791:Quartz
keywords: As; Bioaugmentation; Biogenic Fe-Mn oxides; Community composition and function; Sb