可生物降解螯合剂GLDA诱导葎草修复镉污染土壤

为探究施加螯合剂谷氨酸N，N-二乙酸（GLDA）对诱导葎草修复镉污染土壤的效果，采取盆栽试验研究了镉污染土壤中施加不同浓度GLDA对葎草生长状况、抗氧化酶系统和镉积累特性以及土壤理化性质的影响。结果表明:当螯合剂GLDA施入50 mg/kg的镉污染土壤后，葎草生物量、根长和茎长比对照组显著减少了13.1%~59.1%、6.6%~26.0%和6.8%~10.6%，而葎草的抗氧化酶系统活性整体呈先升后降的趋势，土壤有效态镉含量相比对照组显著提升了10.4%~53.8%；GLDA在浓度为2.5~3.75 mmol/kg时，葎草对镉均有较好的累积净化效果，相比对照组提高了1.29~1.32倍。总体而言，施加2.5 mmol/kg GLDA效果最为理想，此时葎草生长受影响较小，地下和地上部分镉含量分别为对照组的1.07，1.67倍，转运系数、地下部富集系数和地上部富集系数分别为1.00、1.61和1.60。上述结果表明，施加适宜浓度的GLDA能够有效提升葎草对镉污染土壤的修复效率。

BIODEGRADABLE CHELATE GLDA ENHANCED PHYTOEXTRACTION FOR CADMIUM-CONTAMINATED SOIL

The chelating agent could enhance the absorption of plants for heavy metal in soil. To explore the effect of chelating agent L-glutamic acid N, N-diacetic acid (GLDA) enhanced phytoextraction for cadmium-contaminated soil, a pot experiment was conducted to investigate the influence on applying GLDA for the growth, antioxidant enzyme activities and cadmium accumulation characteristic of Humulus scandens and soil physical, chemical properties. The results showed that when the chelating agent GLDA was applied to 50 mg/kg cadmium-contaminated soil, the biomass, root length and stem length of Humulus scandens significantly decreased by 13.1%~59.1%, 6.6%~26.0% and 6.8%~10.6%, compared with the control group; the activity of the antioxidant enzyme system of Humulus scandens increased first and then decreased, and the content of available cadmium in soil significantly increased by 10.4%~53.8%, compared with the control group. GLDA also significantly increased the accumulation of cadmium in various parts of Humulus scandens, and the best accumulation effect of Humulus scandens, which was 1.29~1.32 times higher than the control group, was achieved at the GLDA concentration of 2.50~3.75 mmol/kg. In general, the best results were obtained at 2.5 mmol/kg. In this case, the cadmium content of underground and ground part were 1.07 and 1.67 times higher than the control group, respectively. Further, the translocation factor, underground bioconcentration factor and aboveground bioconcentration factor of Humulus scandens were 1.00, 1.61 and 1.60, respectively. The above results indicated that the application of GLDA of the appropriate concentration could improve the remediation efficiency of humulus scandens in cadmium-contaminated soil.