Lou L Q, Ye Z H, Wong M H
Croucher Institute for Environmental Sciences and Department of Biology, Hong Kong Baptist University, Hong Kong SAR, PR China.
Int J Phytoremediation. 2007 Jul-Aug;9(4):325-43. doi: 10.1080/15226510701475778.
Greenhouse experiments were conducted to study the effects of chelating agents on the growth and metal accumulation of Chinese brake fern (Pteris vittata L.), vetiver (Vetiveria zizanioides L.), and rostrate sesbania (Sesbania rostrata L.) in soil contaminated with arsenic (As), Cu, Pb, and Zn. Among the five chelating agents used [ethylenediaminetriacetic acid (EDTA), hydroxyethylenediaminetriacetic acid (HEDTA), nitrilotriacetic acid (NTA), oxalic acid (OA), and phytic acid (PA)], OA was the best to mobilize As, EDTA to mobilize Cu and Pb, and HEDTA to mobilize Zn from soil, respectively. The biomass of vetiver was the highest, followed by rostrate sesbania. All chelating agents inhibited the growth of Chinese brake fern and rostrate sesbania, but HEDTA significantly increased the aboveground biomass of vetiver. Dry weights of both Chinese brake fern and rostrate sesbania decreased with increasing EDTA concentrations amended in the soil, especially in treatments with high EDTA concentrations. EDTA and HEDTA enhanced Cu, Zn, and Pb, but lowered As accumulation in all three plant species, except for As in vetiver, while OA significantly enhanced As accumulation in the aboveground part of vetiver. Concentrations of Cu, Zn, and Pb in the aboveground parts of plants increased significantly with the increase of EDTA concentrations and treatment time. In addition to As, Chinese brake fern also accumulated the highest Cu, Pb, and Zn in its aboveground parts among the three plant species grown in metal-contaminated soil with EDTA/HEDTA treatments. This species, therefore, can be used to simultaneously clean up As, Cu, Pb, and Zn from contaminated soils with the aid of EDTA or HEDTA.
开展了温室试验，以研究螯合剂对砷（As）、铜（Cu）、铅（Pb）和锌（Zn）污染土壤中蜈蚣草（Pteris vittata L.）、香根草（Vetiveria zizanioides L.）和喙荚田菁（Sesbania rostrata L.）生长及金属积累的影响。在所使用的五种螯合剂[乙二胺三乙酸（EDTA）、羟乙基乙二胺三乙酸（HEDTA）、次氮基三乙酸（NTA）、草酸（OA）和植酸（PA）]中，OA最有利于从土壤中活化As，EDTA最有利于活化Cu和Pb，HEDTA最有利于活化Zn。香根草的生物量最高，其次是喙荚田菁。所有螯合剂均抑制了蜈蚣草和喙荚田菁的生长，但HEDTA显著增加了香根草的地上生物量。随着土壤中添加的EDTA浓度增加，蜈蚣草和喙荚田菁的干重均下降，尤其是在高EDTA浓度处理中。EDTA和HEDTA提高了所有三种植物中Cu、Zn和Pb的含量，但降低了As的积累，香根草中As的积累除外，而OA显著提高了香根草地上部分的As积累。随着EDTA浓度和处理时间的增加，植物地上部分的Cu、Zn和Pb浓度显著增加。除As外，在经EDTA/HEDTA处理的金属污染土壤中生长的三种植物中，蜈蚣草地上部分积累的Cu、Pb和Zn也最高。因此，借助EDTA或HEDTA，该物种可用于同时清除污染土壤中的As、Cu、Pb和Zn。
