Environmental Future Research Institute, Griffith University, Nathan, QLD, 4111, Australia.
Department of Soil Science, Bu-Ali Sina University, Hamadan, Iran.
Environ Sci Pollut Res Int. 2016 Feb;23(3):2479-86. doi: 10.1007/s11356-015-5467-6. Epub 2015 Oct 1.
The low efficiency of phytoremediation is a considerable problem that limits the application of this environmentally friendly method on heavy metal-polluted soils. The combination of chelate-assisted phytoextraction and electrokinetic remediation could offer new opportunities to improve the effectiveness of phytoextraction. The current experiment aims to investigate the effects of electrical fields and chelating agents on phytoremediation efficiency. In a pot experiment using mine soil, poultry manure extract (PME), cow manure extract (CME), and ethylenediaminetetraacetic acid (EDTA) were applied to soil as chelating agents (2 g kg(-1)) at the beginning of the flowering stage. A week later, Helianthus annuus (sunflower) was negatively charged by inserting a stainless steel needle with 10 and 30 V DC electricity in the lowest part of the stems for 1 h each day for a 14-day period. At the end of the experiment, the shoot and root dry weight, lead (Pb) concentration in plant organs, translocation factor (TF), metal uptake index (UI), and soil available Pb (diethylene triamine pentaacetic acid (DTPA) extractable) were detected. Results indicated that the application of electrical fields had no significant impact on the shoot and root dry weights, while Pb concentration and UI increased in the 10-V EDTA treatment by 500 % compared to control. There was no significant difference between UI in 30- and 10-V EDTA treatments. Soil available Pb significantly increased in the 30-V treated soil. A positive correlation was observed between the available Pb in soil near the root and Pb concentration in shoot, its TF, and UI. In conclusion, a negatively charged plant along with the application of EDTA significantly increased the phytoremediation efficiency.
植物修复效率低是限制该环保方法在重金属污染土壤上应用的一个相当大的问题。螯合剂辅助植物提取与电动修复的结合为提高植物提取效率提供了新的机会。本实验旨在研究电场和螯合剂对植物修复效率的影响。在一项利用矿山土壤进行的盆栽实验中，在开花期初期，将鸡粪浸提液（PME）、牛粪浸提液（CME）和乙二胺四乙酸（EDTA）作为螯合剂（2 g kg(-1)) 添加到土壤中。一周后，在向日葵茎的最下部每天插入一根带有 10 和 30 V 直流电的不锈钢针 1 小时，持续 14 天，使向日葵带负电。实验结束时，检测地上部和地下部干重、植物器官中铅（Pb）浓度、迁移系数（TF）、金属吸收指数（UI）和土壤有效态 Pb（二乙三胺五乙酸（DTPA）可提取态）。结果表明，电场的应用对地上部和地下部干重没有显著影响，而在 10-V EDTA 处理中，Pb 浓度和 UI 比对照增加了 500%。在 30-V 和 10-V EDTA 处理之间，UI 没有显著差异。在 30-V 处理的土壤中，土壤有效态 Pb 显著增加。根际土壤中有效态 Pb 与地上部 Pb 浓度、TF 和 UI 呈正相关。总之，带负电的植物与 EDTA 的应用显著提高了植物修复效率。
