5种稳定剂对土壤中4种重金属的稳定效果

Stabilization effect of five stabilizers on four heavy metals in soil

采集被重金属As、Cd、Pb和Zn污染的土壤,选用SiO_2、CaO、CaCO_3、FeSO_4和绿肥5种稳定剂对土壤重金属进行稳定化试验。结果表明:施用单种稳定剂时,FeSO_4对土壤中As的稳定效果最明显,CaO和CaCO_3对土壤Cd、Pb、Zn的稳定效果相对较好,绿肥的稳定效果最差,且5种稳定剂均是随着添加比例的增加对土壤中重金属的稳定效果越好;同时施用2种稳定剂时,FeSO_4和CaO与FeSO_4和CaCO_3均具有较高的稳定效率,3%FeSO_4和3%CaO能达到同时修复As、Cd、Pb、Zn的效果;先后施用FeSO_4和CaO 2种稳定剂时,先加入FeSO_4时,土壤中4种重金属As、Cd、Pb、Zn的稳定效率分别为92.07%、31.08%、27.35%、53.91%,而先加入CaO时,4种重金属As、Cd、Pb、Zn的稳定效率分别为88.21%、40.14%、29.81%、55.12%。可见,在稳定多种重金属时,除了考虑稳定剂的不同配方及比例外,还应考虑添加顺序等。

In this study,one soil containing As,Cd,Zn,Pb was collected and 5 stabilizers of SiO2,CaO,CaCO3,FeSO4 and green manure were applied to the soil to investigate their soil stabilization.The results showed that when only one stabilizer was applied,FeSO4 had the most stable effect on As in the soil,and the stable effects of CaO and CaCO3 on soil Cd,Pb and Zn were relatively fine,the stable effect of green manure was the worst,and the five stabilizers were better in stabilizing the heavy metals in the soil with the increase of the proportion of addition.When the combination of two stabilizers were applied at the same time,FeSO4 with CaO and FeSO4 with CaCO3 had higher stabilization efficiency,and the application of 3%FeSO4 with 3%CaO can repair of As,Cd,Pb and Zn simultaneously.Compared with combined application of two stabilizers with different orders,when FeSO4 was added first,the stabilization efficiency of four heavy metals in the soil were 92.07%,31.08%,27.35%and 53.91%,while CaO was first added,the stabilization efficiency of the four heavy metals were 88.21%,40.14%,29.81%,55.12%.In summary,to stabilize multiple heavy metals in soil,different formulations,ratios and the order of addition should be considered.