title: Enhanced bioreduction of iron and arsenic in sediment by biochar amendment influencing microbial community composition and dissolved organic matter content and composition.
abstract: Biochar derived from the pyrolysis at 500 °C with fresh biogas slurry and residue, was conducted to investigate its potential role in mediating the speciation and mobilization of As(V) and Fe(III) from arsenic-contaminated tailing mine sediment, with consideration of the changes in microbial populations and dissolved organic matter (DOM). The reduction of As(V) (10-13%) and Fe(III) (12-17%) were partly in response to biochar abiotically causing desorption and reduction effect, but were predominantly (87-90% and 83-88% for As(V) and Fe(III)) attributed to biochar stimulating biological reduction. The level of As(III) released from sediment upon biochar amendment (656.35±89.25 μg L(-1)) was significantly higher than the level released without biochar amendment (98.06±19.38 μg L(-1)) after 49 days incubation. Although a low level of Fe(II) (0.81±0.07 mg L(-1)) was determined in the solution when amending with biochar, most of released Fe(II) (166.25±40.25 mg L(-1)) was formed as biochar-Fe(II)minerals composite. More importantly, biochar stimulated the DOM bioavailability in association with bacterial activities mediating As(V) and Fe(III) reduction. High-throughput sequencing results indicated biochar application shifted the soil microbial community and increased the relative abundance of As(V)-/Fe(III)-reducing bacteria, mostly Geobacter, Anaeromyxobacter, Desulfosporosinus and Pedobacter. The discovery of biochar-bacteria-DOM consortium may broaden new understanding into speciation and mobilization of metals, which arouses attention to exploit feasible bioremediation for metal-contaminated sediment.
authors.affiliation: Environmental Science Research Center, College of the Environment & Ecology, Xiamen University, Xiamen, PR China; Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, PR China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, PR China. Electronic address: wypp@xmu.edu.cn.
authors.forename: Yuanpeng
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, PR China.
authors.forename: Dong
authors.initials: D
authors.lastname: Xia
authors.affiliation: Environmental Science Research Center, College of the Environment & Ecology, Xiamen University, Xiamen, PR China.
authors.forename: Xiuli
authors.initials: X
authors.lastname: Jiang
authors.affiliation: Environmental Science Research Center, College of the Environment & Ecology, Xiamen University, Xiamen, PR China.
authors.forename: Dun
authors.initials: D
authors.lastname: Fu
authors.affiliation: Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, PR China.
authors.forename: Liang
authors.initials: L
authors.lastname: Shen
authors.affiliation: Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, PR China.
authors.forename: Haitao
authors.initials: H
authors.lastname: Wang
authors.affiliation: Environmental Science Research Center, College of the Environment & Ecology, Xiamen University, Xiamen, PR China; Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, PR China; College of Chemistry and Life Science, Quanzhou Normal University, Quanzhou, PR China. Electronic address: kelqb@xmu.edu.cn.
authors.forename: Qing Biao
authors.initials: QB
authors.lastname: Li
mesh_terms: D000327:Adsorption; D001151:Arsenic / Q000737:chemistry / Q000378:metabolism*; D001419:Bacteria / Q000235:genetics / Q000378:metabolism; D001673:Biodegradation, Environmental; D002606:Charcoal / Q000737:chemistry*; D005798:Genes, Bacterial; D019015:Geologic Sediments; D007220:Industrial Waste; D007501:Iron / Q000737:chemistry / Q000378:metabolism*; D008906:Mining; D010084:Oxidation-Reduction; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D007220:Industrial Waste; D012336:RNA, Ribosomal, 16S; C540010:biochar; D002606:Charcoal; D007501:Iron; D001151:Arsenic
keywords: Arsenic; Biochar; DOM; Iron; Microbial reduction