四种不同钝化剂对受镉污染农田的修复效果研究

Remediation Effect of Four Different Passivators on Cadmium-Contaminated Farmland

在不同的地区土壤类型不同,钝化剂对其的钝化效果也不一样,选择合适的钝化剂至关重要。研究选取沸石粉、甲壳素、TG土壤调理剂及MT土壤调理剂四种钝化剂对北方典型受Cd污染农田进行钝化修复,对比其钝化前后土壤理化性质及重金属含量,进而选择适合于当地的钝化剂。结果表明,沸石粉对受污染农田pH值的影响最大,MT修复剂可以显著提高土壤中有机质含量7.2%,四种钝化剂对土壤Cd的钝化率为1.4%~13.9%,土壤中Cd的下降率效果最明显的为甲壳素13.9%,TG修复剂和MT修复剂对土壤中有效态砷的平均钝化率较高分别为22.56%,18.80%。甲壳素可以有效减小植物不同部位之间重金属的转运率,尤其在茎叶向籽粒转移部分,甲壳素对此部位转运率见效率为其他处理的1.06~1.91倍。综合考虑甲壳素更适合于当地土壤重金属钝化修复。

In different regions,the soil types are different,and the passivation effect of the passivation agent is also different.It is very important to choose the appropriate passivation agent.In this study,four passivation agents,zeolite powder,chitin,TG soil conditioner and MT soil conditioner,were selected for the passivation and restoration of typical Cd-contaminated farmland in the north.Compare the soil physicochemical properties and heavy metal content before and after passivation,and then select a suitable passivation agent for the local area.The results showed that zeolite powder had the greatest impact on the pH value of contaminated farmland,MT remediation agent could significantly increase soil organic matter content by 7.2%,and the four passivation agents had a passivation rate of 1.4%~13.9%for soil Cd.The most obvious reduction rate of arsenic was 13.9%for chitin,and the average passivation rates of TG and MT for arsenic in soil were 22.56%and 18.80%,respectively.Chitin can effectively reduce the transport rate of heavy metals between different parts of plants,especially in the transfer part from stems and leaves to grains.The transport rate of chitin in this part is 1.06~1.91 times that of other treatments.Considering comprehensively,chitin is more suitable for local soil heavy metal passivation remediation.