College of Land Science and Technology, China University of Geosciences, Beijing, No.29, Xueyuan Road, Haidian District, Beijing, 100083, China.
School of Water Resources and Environment, China University of Geosciences, Beijing, No.29, Xueyuan Road, Haidian District, Beijing, 100083, China.
Chemosphere. 2021 Apr;269:129373. doi: 10.1016/j.chemosphere.2020.129373. Epub 2020 Dec 19.
Chelating agent-induced phytoremediation is a viable approach to completely remove heavy metals from soil. However, little attention has been paid to the interaction mechanisms between the concentration of the chelating agent and the application time on the physiological and biochemical properties of soil and plants. In this study, five chelating agents, namely ethylenediamine tetraacetic acid (EDTA), diethylenetriacetic acid (NTA), tetrasodium N, N-diacetate (GLDA), aspartate dibutyric acid ether (AES), and iminodisuccinic acid (IDSA), were used to support phytoremediation with maize and to explore the removal effect of Cd in soil. The results showed that chelating agent concentrations of 9 mmol kg significantly reduced the biomass of maize. Treatment with AES at a dose of 6 mmol kg significantly increased aboveground biomass, reaching a maximum of 0.92 g pot in all treatments. At an AES concentration of 6 mmol kg, the highest shoot and root Cd levels of 7.79 and 9.86 mg kg, respectively, were observed, which were 3.05 and 1.60 times higher than those of the control. Total Cd extraction followed the order AES (6 mmol kg) > GLDA > NTA > EDTA > IDSA (3 mmol kg). Chelating agent treatment significantly increased the activity of antioxidant enzymes and promoted plant growth. The self-degradation of AES significantly reduced soil pH, increased soil Cd activity, and promoted Cd uptake and transportation in maize.
螯合剂诱导的植物修复是一种可行的方法，可以彻底去除土壤中的重金属。然而，人们很少关注螯合剂浓度和应用时间对土壤和植物生理生化特性的相互作用机制。本研究采用乙二胺四乙酸（EDTA）、二乙三胺五乙酸（NTA）、四乙酸钠（GLDA）、天冬氨酸二丁酸醚（AES）和亚氨基二琥珀酸（IDSA）五种螯合剂，通过玉米支持植物修复，并探讨土壤中 Cd 的去除效果。结果表明，螯合剂浓度为 9 mmol kg 时，玉米生物量明显降低。6 mmol kg 的 AES 处理显著增加地上生物量，在所有处理中达到最高的 0.92 g 盆。在 AES 浓度为 6 mmol kg 时，观察到最高的地上部和根部 Cd 含量分别为 7.79 和 9.86 mg kg，分别比对照高出 3.05 倍和 1.60 倍。总 Cd 提取量的顺序为 AES（6 mmol kg）>GLDA>NTA>EDTA>IDSA（3 mmol kg）。螯合剂处理显著增加了抗氧化酶的活性，促进了植物的生长。AES 的自降解显著降低了土壤 pH 值，增加了土壤 Cd 活性，促进了 Cd 在玉米中的吸收和运输。
