Heavy metal fates in laboratory bioretention systems.
Heavy metal fates in laboratory bioretention systems.
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DOI：
10.1016/j.chemosphere.2006.08.013
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发表时间：
2007
期刊：
影响因子：
8.8
通讯作者：
Xueli Sun;A. Davis
中科院分区：
文献类型：
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作者：
Xueli Sun;A. Davis
生物滞留中重金属管理的关键是了解它们在生物滞留设施中的命运。在这项研究中，盆栽原型充满了生物滞留介质，以模拟植物的自然生长条件。定期施加不同重金属负荷（铜，镉，铅，锌）的合成径流。在230 d的生长和多次径流处理事件后，研究了禾本科植物柳枝稷、肯塔基州-31和Bromus ciliatus组织中的金属累积。经过183 d的径流周期性处理后，Zn、Cu、Pb、Cd在植物组织中的浓度变化趋势基本一致，Zn>Cu>Pb>Cd，与输入金属浓度的变化趋势一致。输入重金属88-97%被土壤介质捕获，2.0-11.6%未被生物滞留介质捕获，0.5-3.3%积累在植物中。与土壤中保留的金属相比，由于本研究中产生的植物生物量较低，植物吸收的输入金属百分比相对较低。植被要在延长生物滞留单元的寿命方面产生有价值的影响，就需要更大的生物量密度。
Key to managing heavy metals in bioretention is to understand their fates in bioretention facilities. In this study, pot prototypes filled with bioretention media were built to simulate the conditions of natural growth of plants. Synthetic runoff with different heavy metal loadings (copper, cadmium, lead, and zinc) was periodically applied. Metal accumulations in tissues of grasses –Panicum virgatum, Kentucky-31, and Bromus ciliatus, were investigated after 230d of growth and multiple runoff treatment events. After 183d of periodic runoff application, the concentrations of Zn, Cu, Pb and Cd with low and high loadings had the same trends in the plant tissues, Zn>Cu>Pb>Cd, following the trend of the input metal concentrations. The fates of input metals were 88–97% captured in soil media, 2.0–11.6% not captured by bioretention media, and 0.5–3.3% accumulated in plants. Compared to the metals retained by the soil, the percentages of input metals taken up by plants were relatively low due to the low plant biomass produced in this study. Greater biomass density would be required for the vegetation to have a valuable impact in prolonging the lifetime of a bioretention cell.