title: Efficiency and mechanism of the phytoremediation of decabromodiphenyl ether-contaminated sediments by aquatic macrophyte Scirpus validus.
abstract: Phytoremediation is an economic and promising technique for removing toxic pollutants from the environment. Freshwater sediments are regarded as the ultimate sink of the widely used PBDE congener decabromodiphenyl ether (BDE-209) in the environment. In the study, the aquatic macrophyte Scirpus validus was selected to remove BDE-209 from three types of sediments (silt, clay, and sand) at an environmentally relevant concentration. After 18 months of phytoremediation experiment, S. validus significantly enhanced the dissipation rates of BDE-209 in all the sediments compared to the controls. Average removal rates of BDE-209 in the three treatments of silt, clay, and sandy sediments with S. validus were respectively 92.84, 84.04, and 72.22%, which were 148, 197, and 233% higher than that in the control sediments without S. validus. In the phytoremediation process, the macrophyte-rhizosphere microbe combined degradation was the main pathway of BDE-209 removal. Sixteen lower brominated PBDE congeners (di- to nona-) were detected in the sediments and plant tissues, confirming metabolic debromination of BDE-209 in S. validus. A relatively higher proportion of penta- and di-BDE congeners among the metabolites in plant tissues than that in the sediments indicated further debromination of PBDEs within plants. The populations and activities of microorganisms in the sediments were greatly promoted by S. validus. Bacterial community structure in BDE-209-contaminated rhizosphere sediments was different from that in the control rhizosphere sediment, as indicated by the dominant proportions of β-proteobacteria, δ-proteobacteria, α-proteobacteria, Acidobacteria, and Chloroflexi in the microbial flora. All these results suggested that S. validus was effective in phytoremediation of BDE-209 by the macrophyte-rhizosphere microbe combined degradation in aquatic sediments.
authors.affiliation: School of Life Sciences, Central China Normal University, Wuhan, 430079, China.|Basin Water Environmental Research Department, Yangtze River Scientific Research Institute, Wuhan, 430010, China.
authors.forename: Liangyuan
authors.initials: L
authors.lastname: Zhao
authors.affiliation: School of Life Sciences, Central China Normal University, Wuhan, 430079, China.
authors.forename: Jinhui
authors.initials: J
authors.lastname: Jiang
authors.affiliation: School of Life Sciences, Central China Normal University, Wuhan, 430079, China.|Key Laboratory of Nuclear Resources and Environment, Ministry of Education, East China University of Technology, Fuzhou, 344000, China.
authors.forename: Chuanhong
authors.initials: C
authors.lastname: Chen
authors.affiliation: School of Life Sciences, Central China Normal University, Wuhan, 430079, China.
authors.forename: Shuie
authors.initials: S
authors.lastname: Zhan
authors.affiliation: School of Life Sciences, Central China Normal University, Wuhan, 430079, China.
authors.forename: Jiaoyan
authors.initials: J
authors.lastname: Yang
authors.affiliation: School of Life Sciences, Central China Normal University, Wuhan, 430079, China. mryangshao@126.com.
authors.forename: Shao
authors.initials: S
authors.lastname: Yang
mesh_terms: D001673:Biodegradation, Environmental; D019015:Geologic Sediments / Q000737:chemistry*; D055768:Halogenated Diphenyl Ethers; D014874:Water Pollutants, Chemical
chemical_list: D055768:Halogenated Diphenyl Ethers; D014874:Water Pollutants, Chemical; C010902:decabromobiphenyl ether
keywords: Aquatic macrophyte; BDE-209; Mechanism; Phytoremediation; Removal; Sediment