Zhao Liangyuan, Jiang Jinhui, Chen Chuanhong, Zhan Shuie, Yang Jiaoyan, Yang Shao
School of Life Sciences, Central China Normal University, Wuhan, 430079, China.
Basin Water Environmental Research Department, Yangtze River Scientific Research Institute, Wuhan, 430010, China.
Environ Sci Pollut Res Int. 2017 May;24(14):12949-12962. doi: 10.1007/s11356-017-8900-1. Epub 2017 Apr 3.
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.
植物修复是一种从环境中去除有毒污染物的经济且有前景的技术。淡水沉积物被视为环境中广泛使用的多溴二苯醚同系物十溴二苯醚（BDE - 209）的最终归宿。在本研究中，选用水生大型植物芦苇来去除环境相关浓度下三种类型沉积物（粉砂、黏土和沙子）中的BDE - 209。经过18个月的植物修复实验，与对照相比，芦苇显著提高了所有沉积物中BDE - 209的消散速率。在有芦苇的粉砂、黏土和砂质沉积物三种处理中，BDE - 209的平均去除率分别为92.84%、84.04%和72.22%，分别比没有芦苇的对照沉积物高148%、197%和233%。在植物修复过程中，大型植物 - 根际微生物联合降解是BDE - 209去除的主要途径。在沉积物和植物组织中检测到16种低溴化多溴二苯醚同系物（二溴至九溴），证实了芦苇中BDE - 209的代谢脱溴作用。植物组织中代谢产物中五溴和二溴二苯醚同系物的比例相对高于沉积物，表明植物体内多溴二苯醚进一步脱溴。芦苇极大地促进了沉积物中微生物的数量和活性。受BDE - 209污染的根际沉积物中的细菌群落结构与对照根际沉积物不同，微生物菌群中β - 变形菌、δ - 变形菌、α - 变形菌、酸杆菌和绿弯菌占主导比例。所有这些结果表明，芦苇通过水生沉积物中大型植物 - 根际微生物联合降解对BDE - 209进行植物修复是有效的。
