Groupe de Recherche en Physiologie Végétale, Earth and Life Institute, Université catholique de Louvain, Louvain-la-Neuve, Belgium.
Chemosphere. 2011 Nov;85(8):1290-8. doi: 10.1016/j.chemosphere.2011.07.034. Epub 2011 Aug 12.
Phytoremediation is a promising and cost-effective strategy to manage heavy metal polluted sites. In this experiment, we compared simultaneously phytoextraction and phytostabilisation techniques on a Cd and Zn contaminated soil, through monitoring of plant accumulation and leaching. Lolium perenne plants were cultivated for 2 months under controlled environmental conditions in a 27.6 dm(3)-pot experiment allowing the collect of leachates. The heavy metal phytoextraction was promoted by adding Na-EDTA (0.5 g kg(-1) of soil) in watering solution. Phytostabilisation was assessed by mixing soil with steel shots (1%) before L. perenne sowing. Presence of plants exacerbated heavy metal leaching, by improving soil hydraulic conductivity. Use of EDTA for phytoextraction led to higher concentration of heavy metal in shoots. However, this higher heavy metal extraction was insufficient to satisfactory reduce the heavy metal content in soil, and led to important heavy metal leaching induced by EDTA. On the other hand, addition of steel shots efficiently decreased both Cd and Zn mobility, according to 0.01 M CaCl(2) extraction, and leaching. However, improvement of growth conditions by steel shots led to higher heavy metal mass in shoot tissues. Therefore, soil heavy metal mobility and plant metal uptake are not systematically positively correlated.
植物修复是管理重金属污染场地的一种有前途且具有成本效益的策略。在本实验中，我们通过监测植物积累和淋洗，比较了同时进行的植物提取和植物稳定技术对 Cd 和 Zn 污染土壤的效果。在一个 27.6 dm³的盆式实验中，通过控制环境条件，在 2 个月的时间里种植黑麦草，允许收集淋出液。通过在浇水溶液中添加 Na-EDTA（土壤的 0.5 g kg(-1)）来促进重金属的植物提取。通过在播种黑麦草之前将土壤与钢珠（1%）混合来评估植物稳定化。植物的存在通过提高土壤水力传导率加剧了重金属淋洗。EDTA 用于植物提取导致了更高浓度的重金属在地上部分。然而，这种更高的重金属提取不足以令人满意地降低土壤中的重金属含量，并导致 EDTA 引起的重要重金属淋洗。另一方面，钢珠的添加根据 0.01 M CaCl(2)提取和淋洗，有效地降低了 Cd 和 Zn 的迁移性。然而，钢珠改善了生长条件，导致地上部分组织中重金属的质量更高。因此，土壤重金属的迁移性和植物对金属的吸收并不系统地呈正相关。
