Sequestration of precious and pollutant metals in biomass of cultured water hyacinth (Eichhornia crassipes)
Sequestration of precious and pollutant metals in biomass of cultured water hyacinth (Eichhornia crassipes)
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DOI：
10.1007/s11356-016-7292-y
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发表时间：
2016-07
影响因子：
5.8
通讯作者：
Solomon W. Newete;B. Erasmus;I. Weiersbye;M. Byrne
中科院分区：
文献类型：
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作者：
Solomon W. Newete;B. Erasmus;I. Weiersbye;M. Byrne
本研究的目的是调查金属污染物的整体根/茎分配、根内或外表面吸收和吸附去除的金属量、水葫芦金属吸收的剂量反应以及植物毒性。在单金属桶试验中对此进行了检查，使用砷 (As)、金 (Au)、铜 (Cu)、铁 (Fe)、汞 (Hg)、锰 (Mn)、铀 (U) 和锌 (Zn)。铁和锰也被用于低、中、高浓度处理，以测试它们对水葫芦金属吸收的剂量效应。水葫芦一般对除铜和汞以外的金属毒性具有耐受性。去除的金属总量的 80% 以上积累在根部，其中 30-52% 被吸附到根部表面。此外，水葫芦吸收的金属总量的 73-98% 位于根部。 Cu、Hg、Au和Zn的生物富集因子(BCF)超过了用于选择植物修复植物的推荐指数1000，但U、As和Mn的生物富集因子没有超过。然而，Mn 的 BCF 随着水中 Mn 浓度的增加而增加。这表明，仅使用 BCF 指数，而不考虑植物生物量和水中金属浓度，不足以准确确定植物的植物修复潜力。因此，这项研究证实了水葫芦具有广泛的植物修复作用的潜力。然而，了解这些金属是否被吸附在植物组织上或在植物组织内同化，以及了解它们在根和芽之间的分配，将为决定如何重新处理生物质以回收金属，或减少生物质以在植物修复后安全处置的方式提供信息。
The aim of this study was to investigate the overall root/shoot allocation of metal contaminants, the amount of metal removal by absorption and adsorption within or on the external root surfaces, the dose-response of water hyacinth metal uptake, and phytotoxicity. This was examined in a single-metal tub trial, using arsenic (As), gold (Au), copper (Cu), iron (Fe), mercury (Hg), manganese (Mn), uranium (U), and zinc (Zn). Iron and Mn were also used in low-, medium-, and high-concentration treatments to test their dose effect on water hyacinth’s metal uptake. Water hyacinth was generally tolerant to metallotoxicity, except for Cu and Hg. Over 80 % of the total amount of metals removed was accumulated in the roots, of which 30–52 % was adsorbed onto the root surfaces. Furthermore, 73–98 % of the total metal assimilation by water hyacinth was located in the roots. The bioconcentration factor (BCF) of Cu, Hg, Au, and Zn exceeded the recommended index of 1000, which is used in selection of phytoremediating plants, but those of U, As, and Mn did not. Nevertheless, the BCF for Mn increased with the increase of Mn concentration in water. This suggests that the use of BCF index alone, without the consideration of plant biomass and metal concentration in water, is inadequate to determine the potential of plants for phytoremediation accurately. Thus, this study confirms that water hyacinth holds potential for a broad spectrum of phytoremediation roles. However, knowing whether these metals are adsorbed on or assimilated within the plant tissues as well as knowing their allocation between roots and shoots will inform decisions how to re-treat biomass for metal recovery, or the mode of biomass reduction for safe disposal after phytoremediation.