磷回收产物对土壤中铜的原位修复作用

In-situ remediation of copper in contaminated soil by addition of phosphorus recovery product

以鸟粪石形式回收废水中磷酸盐并将其应用于土壤中铜的钝化,通过测定土壤中pH、铜有效态含量和各形态铜含量等以考察磷回收产物(PRP材料)对土壤重金属铜的钝化修复能力,并用SEM/EDS和XRD等表征手段来揭示其修复机理。实验结果表明,PRP材料的主要成分为负载有鸟粪石的人造沸石;在15%PRP材料的投加比例下,土壤的pH增加了0.47个单位,土壤中铜有效态含量减少了50.4%,可交换态含量降低了49.4%,残渣态增加至2.1倍,一定程度上降低了铜在土壤中的生物活性;PRP材料对土壤中重金属Cu的钝化机制主要为吸附和沉淀的协同作用。

The phosphate in sewage was recovered in the form of struvite and applied to stabilize Cu in contaminated soil. The stabilization effect of the phosphorus recovery product（ PRP） was explored by determination of the pH,available concentration analysis,and the forms and variants of Cu in soils. The remediation mechanism was studied using SEM/EDS and XRD. The results showed that,the main component in the PRP material was synthetic zeolite,carrying a struvite composite material. The PRP performed best for immobilization of Cu-polluted soil when added at a mass rate of 15%. Specifically,the pH of the soil increased by 0. 47,and the amount of bioavailable Cu and exchangeable Cu declined by 50. 4% and 49. 4%,respectively. Residual Cu increased 2.1 times,compared with CK,thereby reducing the activity of Cu in the soil. The passivation mechanisms of the PRP were mainly adsorption and precipitation.