不同钝化剂对铅镉重金属污染土壤的修复影响研究

Study on the effects of different passivation agents on remediation of lead and cadmium heavy metal contaminated soil

为研究不同种类钝化剂对铅、镉重金属污染土壤的修复效果影响,选择某化工厂铅、镉污染比较严重的黄壤作为修复对象,采用单一的无机钝化剂、生物炭类钝化剂、矿物钝化剂和有机-无机混合钝化剂对土壤进行修复。在不同类型钝化剂下,设计三因素三水平正交实验,除了钝化剂类型之外,所有条件都相似,研究上述各个类型钝化剂对土壤中铅、镉含量的钝化效率影响。研究结果表明,实验中所选择的生物炭、石灰、含硫型土壤调理剂、硅藻土按照一定比例混合而成的矿物钝化剂,对受试土壤中重金属铅、镉的钝化效果最好;通过正交实验结果可知,在矿物钝化剂使用量为460kg·hm^(-2)、土壤水分为50%、土壤粒径>2mm的情况下,能够获得最佳的铅、镉钝化效果,钝化效率分别为79.85%和87.18%。

In order to study the effects of different types of passivation agents on the remediation of lead and cadmium heavy metal contaminated soil,a yellow soil contaminated by lead and cadmium in a chemical plant was selected as the remediation object,and a single inorganic passivation agent,biochar passivation agent,mineral passivation agent,and organic-inorganic mixed passivation agent were used to repair the soil.Under different types of passivation agents,a three factor and three level orthogonal experiment was conducted to study the effects of various types of passivation agents on the passivation efficiency of lead and cadmium content in soil,with all conditions similar except for the type of passivation agent.The results showed that the mineral passivation agent selected in the experiment,which was mixed with biochar,lime,sulfur-containing soil conditioner,and diatomite in a certain proportion,had the best passivation effect on heavy metals such as lead and cadmium in the tested soil;According to the orthogonal experimental results,when the amount of mineral passivation agent used was 460kg·hm^(-2),soil moisture was 50%,and soil particle size was more than 2mm,the best passivation effects of lead and cadmium could be obtained,with passivation efficiency of 79.85%and 87.18%,respectively.