氨基酸盐对镉污染土壤的淋洗效果

Leaching effect of amino acid salts on cadmium contaminated soil

以湖南湘潭受镉污染的农田土壤为研究对象,采用振荡淋洗技术,以氯化甘氨酸盐和硝酸甘氨酸盐作为淋洗剂,研究了在不同工艺条件下对农田土壤中重金属镉的去除效果,测定了淋洗前后土壤理化性质和结构的变化。结果表明,2种氨基酸盐对镉的去除率最高可分别达到84.3%和78.4%,淋洗后镉的有效态(可氧化态+酸溶态)质量分数显著减少。淋洗使土壤pH值显著下降,但有机质、碱解氮以及速效磷含量显著上升,阳离子交换量以及速效钾含量下降。淋洗对土壤结构无明显破坏,且淋洗修复后的农田土壤重金属含量大幅降低。说明,氨基酸盐作为淋洗剂对土壤中镉具有较高的去除率且是种新型的环保淋洗剂,具有巨大的应用价值。

Taking the farmland soil polluted by cadmium(Cd)in Xiongtan of Hunan province as the reasearch object,the removal effect of amino acid salt on Cd in farmland soil under different technological conditions was studied by using oscillating washing technology.The glycine hydrochloride([Gly][Cl])and glycine nitrate([Gly][NO3])were used as eluting reagents,and the changes of soil physical and chemical properties before and after leaching were measured.The results showed that the highest removal rate of Cd by the two amino acid salts was 84.3%and 78.4%,respectively,and the available Cd was significantly reduced after leaching.In addition,the pH value of the soil decreased significantly after leaching,the contents of organic matter,available nitrogen and available phosphorus increased significantly,and the content of available potassium and cation exchange capacity decreased.There was no obvious damage to soil structure by leaching,the content of heavy metals in the farmland soil after leaching and repairing was greatly reduced.In conclusion,the amino acid salt has a high removal rate of Cd in the soil.