Faculty of Agriculture, Moshtohor, Benha University, Qhalubia, Egypt.
Chemosphere. 2013 Jan;90(2):588-94. doi: 10.1016/j.chemosphere.2012.08.042. Epub 2012 Sep 16.
EDTA amendments are widely used for micronutrient fertilization in arid soils, besides their effectiveness in the remediation process of heavy metal from contaminated soils. However, the persistence of EDTA in arsenic contaminated soil may have further negative effects on the grown plants. To investigate the influences of EDTA on soil As, a pot experiment was conducted using a sandy clay loam As-polluted soil treated with gradual rates of EDTA (0, 1.0, 2.5 and 5 mmol kg(-1)) and planted with maize for two months. The key findings reveal that EDTA applications increased AB-DTPA extractable and water soluble As significantly. Such increases seemed to be the main reasons behind the increase in As uptake by maize plants as the addition of EDTA at the rates of 1.0, 2.5 and 5.0 mmol kg(-1) increased significantly As uptake by shoots 1.5, 2.4 and 3.0 folds, respectively compared to the untreated soil. On the other hand, As uptake by roots did not increase significantly except with the highest application rates of 2.5 and 5.0 mmol kg(-1). The results also show that arsenic translocation factor (TF) values were too low to attain successful phytoextraction. In conclusion, the bioavailable fraction of As is important to investigate the phytoextraction and phytotoxicity of As.
EDTA 修正案被广泛应用于干旱土壤中的微量营养素施肥，除了在受污染土壤的重金属修复过程中的有效性。然而，EDTA 在砷污染土壤中的持久性可能对生长中的植物产生进一步的负面影响。为了研究 EDTA 对土壤砷的影响，采用含有逐渐增加 EDTA（0、1.0、2.5 和 5mmolkg(-1))的砂壤土砷污染土壤进行了盆栽实验，并种植了玉米两个月。主要发现表明，EDTA 的应用显著增加了 AB-DTPA 可提取和水溶性砷。由于添加 EDTA 的浓度分别为 1.0、2.5 和 5.0mmolkg(-1)时，玉米植株对砷的吸收分别增加了 1.5、2.4 和 3.0 倍，超过了未处理土壤，这种增加似乎是玉米植物吸收砷增加的主要原因。另一方面，根对砷的吸收并没有显著增加，除了最高添加浓度为 2.5 和 5.0mmolkg(-1)。结果还表明，砷迁移因子（TF）值太低，无法成功进行植物提取。总之，可利用的砷含量对研究砷的植物提取和植物毒性很重要。
