College of Natural Resources and Environment, Key Laboratory of Ecological Agricultural of Ministry of Agriculture of China, South China Agricultural University, Guangzhou, China.
Int J Phytoremediation. 2011 Aug;13(7):717-29. doi: 10.1080/15226514.2010.525554.
Phytoextraction using hyperaccumulating plants is generally time-consuming and requires the cessation of agriculture. We coupled chelators and a co-cropping system to enhance phytoextraction rates, while allowing for agricultural production. An experiment on I m3 lysimeter beds was conducted with a co-cropping system consisting of the hyperaccumulator Sedum alfredii and low-accumulating corn (Zea Mays, cv. Huidan-4), with addition ofa mixture of chelators (MC), to assess the efficiency of chelator enhanced co-crop phytoextraction and the leaching risk caused by the chelator. The results showed that the addition of MC promoted the growth of S. alfredii in the first crop (spring-summer season) and significantly increased the metal phytoextraction. The DTPA-extractable and total metal concentrations in the topsoil were also reduced more significantly with the addition of MC compared with the control treatments. However, mono-cropped S. alfredii without MC was more suitable for maximizing S. alfredii growth and therefore phytoextraction of Zn and Cd during the autumn-winter seasons. No adverse impact to groundwater due to MC application was observed during the experiments with three crops and three MC applications. But elevated total Cd and Pb concentrations among subsoils compared to the initial subsoil concentrations were found for the co-crop + MC treatment after the third crop.
利用超积累植物进行植物提取通常耗时较长，并且需要停止农业生产。我们将螯合剂和间作系统相结合，以提高植物提取率，同时允许进行农业生产。在一个 1 立方米的淋溶床实验中，采用超积累植物景天（Sedum alfredii）和低积累玉米（Zea Mays，cv. Huidan-4）的间作系统，添加混合螯合剂（MC），以评估螯合剂增强间作植物提取的效率和螯合剂引起的淋溶风险。结果表明，添加 MC 促进了第一茬作物（春夏季节）中 S. alfredii 的生长，并显著增加了金属的植物提取。与对照处理相比，添加 MC 还能更显著地降低表土中 DTPA 可提取和总金属浓度。然而，在秋冬季节，没有 MC 的单作 S. alfredii 更适合最大限度地促进 S. alfredii 的生长，从而提取 Zn 和 Cd。在三茬作物和三次 MC 应用的实验中，没有观察到 MC 应用对地下水造成不利影响。但是，在第三茬作物后，间作+MC 处理的底土中总 Cd 和 Pb 浓度较初始底土浓度升高。
