SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Environmental Theoretical Chemistry, South China Normal University, Guangzhou 510006, China.
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Sci Total Environ. 2019 Oct 15;687:1098-1106. doi: 10.1016/j.scitotenv.2019.06.170. Epub 2019 Jun 14.
Selenite(IV) and selenate(VI) are the major species of Se in the seleniferous aquatic ecosystem. The redistribution of Se in the water/sediment microcosm by bioturbation remains largely unknown. In this study, the redistribution of Se in the water/sediment microcosm by the benthic oligochaete Limnodrilus hoffmeisteri was assessed. The worms were exposed to 2-40 μg/g dry weight of Se(IV) or Se(VI) in the sediment (diet) for 2 months. The changes in the Se levels in different compartments of the microcosm (sediment, overlying water, and worms) were quantified after 2 weeks and 2 months. The subcellular distribution of Se in the worms were also evaluated. Finally, the volatilization of Se from the two Se sources was estimated. The results showed that Se concentration in the overlying water and Se bioaccumulation in the worms were increased with Se levels in the sediments. Approximately 1.6-9.8% of Se was volatilized in the absence of the worms and was intensified in the presence of the worms (2.1-25.7%). The subcellular distribution witnessed high levels of Se in the cell debris (>60%). Se(IV) and Se(VI) differ in their bioaccumulation, redistribution and the effects on the growth of the worms. Our results suggest that the bioturbation by benthos play an essential role in the redistribution of Se in the water/sediment microcosm.
亚硒酸盐(IV)和硒酸盐(VI)是富硒水生生态系统中硒的主要存在形式。生物扰动对水-沉积物微宇宙中硒的再分配作用仍知之甚少。本研究评估了底栖寡毛类Limnodrilus hoffmeisteri 对水-沉积物微宇宙中硒的再分配作用。将这些蠕虫暴露于沉积物(饮食)中 2-40μg/g 干重的 Se(IV)或 Se(VI)中 2 个月。在 2 周和 2 个月后，定量测定微宇宙不同隔室(沉积物、上覆水和蠕虫)中硒的含量变化。还评估了蠕虫中硒的亚细胞分布。最后，估计了两种硒源的硒挥发量。结果表明，上覆水中的硒浓度和蠕虫中的硒生物积累随沉积物中的硒水平而增加。在没有蠕虫的情况下，约有 1.6-9.8%的硒挥发，而在有蠕虫的情况下，挥发量增加(2.1-25.7%)。亚细胞分布显示，细胞碎片中的硒含量很高(>60%)。Se(IV)和 Se(VI)在生物积累、再分配和对蠕虫生长的影响方面存在差异。我们的研究结果表明，底栖生物的生物扰动在水-沉积物微宇宙中硒的再分配中起着重要作用。
