不同有机酸对石灰性土壤镉污染修复效应研究

Effect of Different Organic Acids on Cadmium Pollution in Calcareous Soil

【目的】研究不同有机酸和滴灌技术结合对土壤镉污染的修复效应。【方法】采用盆栽试验,将有机酸溶液分时期滴入土壤中,测定玉米和小白菜土壤的不同形态镉含量。【结果】不同分子量有机酸对小白菜土壤镉修复效果为柠檬酸>酒石酸>草酸>黄腐酸,玉米为柠檬酸>草酸>黄腐酸>酒石酸。混合酸与单施有机酸中,对小白菜土壤镉修复效果为酒石酸>草酸+黄腐酸>酒石酸+黄腐酸>草酸>黄腐酸,玉米为草酸>黄腐酸>草酸+黄腐酸>酒石酸>酒石酸+黄腐酸。硝酸浸提有机肥对玉米和小白菜修复效果均较好。【结论】在小白菜土壤中,单施柠檬酸与单施酒石酸修复效果较好,玉米为单施柠檬酸和单施草酸修复效果较好;有机肥硝酸浸提液对两种作物修复效果均较好。

【Objective】Organic acids can affect soil adsorption or soil desorption of heavy metals. In this study,we aims to explore the effect of combining different organic acids with the drip irrigation on the cadmium remediation in calcareous soil.【Method】In this pot experiment,organic acid solution was dripped into the soil in different periods to determine the different forms of cadmium in maize and cabbage soil.【Result】The effects of different molecular organic acids on the remediation of cadmium in Chinese cabbage was in the order of citric acid tartaric acid oxalic acid fulvic acid,and citric acid oxalic acid fulvic acid tartaric acid in corn soil. For mixed acid and single organic acid,the overall remediation effect of cadmium in Chinese cabbage was in the order of tartaric acid oxalic acid ＋ fulvic acid tartaric acid ＋ fulvic acid oxalic acid fulvic acid,and oxalic acid fulvic acid oxalic acid ＋ fulvic acid tartaric acid tartaric acid ＋ fulvic acid in corn soil. The effect of organic fertilizer extracted from nitric acid on both corn and Chinese cabbage was better.【Conclusion】In Chinese cabbage soil,citric acid alone and tartaric acid alone have the better remediation effect,and citric acid and oxalic acid was better in corn soil. Remediation effect of nitric acid organic fertilizer extract was better for both crops.