中文摘要：

通过盆栽莴苣试验,研究施加草酸活化磷矿粉对矿区农田土壤Cd污染钝化修复的效果。结果表明：施加南漳磷矿粉后,供试土壤交换态Cd的含量比对照降低了12.5%～20.3%;施加不同浓度经草酸活化过的南漳磷矿粉后,交换态Cd的含量与对照相比最高降低了39.5%。施加保康磷矿粉后,随着施加量的增加,与对照相比,交换态Cd的含量变化不显著;施加经草酸活化保康磷矿粉,土壤交换态Cd含量比对照最高降低了21.5%。同时,与对照相比,施加南漳磷矿粉后,残渣态Cd含量最大值是对照的2.03倍,施加经草酸活化的南漳磷矿粉后,残渣态Cd含量最大值是对照的2.61倍;施加保康磷矿粉和活化磷矿粉后,残渣态Cd含量与对照也有显著增加。施加磷矿粉和活化磷矿粉可以显著降低莴苣各部分对Cd的吸收,减少Cd在莴苣植株的累积。在施加两种活化磷矿粉后,与对照相比,莴苣地上部分Cd含量分别最多可降低41.4%、59.3%,根部Cd含量最多降低47.7%、55.1%。因此,低品位磷矿粉经草酸活化后施于Cd污染土壤,可以更好地钝化固定土壤中的Cd。

英文摘要：

A pot experiment was conducted to study the Cd immobilization effect of oxalic acid activated phosphate rocks on a contaminated soil in mining area,using lettuce as a test crop.The results showed that when applied Nanzhang phosphate rock,the content of exchangeable Cd in the soil was reduced by 12.5%～20.3%.Application of oxalic acid activated Nanzhang phosphate rock at different levels,decreased the content of exchangeable Cd up to 39.5%,compared with the control treatment.The change in the content of exchangeable Cd as the amount of applied Baokang phosphate rock increased was slightly significant.The maximum reduction of 21.5% exchangeable Cd was obtained after applying Baokang activated phosphate rock to the soil.At the same time,the maximum content of residual Cd was 2.03 times higher than the control of the treatments with Nanzhang phosphate rock,while it was 2.61 times higher than the control of the treatments with Nanzhang activated phosphate rock.The contents of residual Cd among the treatments with Baokang phosphate rock and activated phosphate rock were significantly higher than the control.Application of phosphate rocks and activated phosphate rocks to the soil could significantly reduce the Cd uptake and accumulation in various parts of lettuce.However,the low-grade phosphate rocks activated by oxalic acid had a better effect than raw phosphate rocks on immobilization of Cd when applied to the contaminated soil.