热解吸工艺放置顺序对土壤重金属稳定化效果的影响

Influence of thermal desorption process placement sequence on stabilization effect of soil heavy metals

为了研究热解吸工艺放置顺序对土壤重金属稳定化效果的影响,通过小试模拟的方式,对不同种类的土壤样品进行实验,对比分析了土壤的关键指标在加热前后的变化。结果表明,当热解吸工艺放置在添加稳定化药剂前时,会提高土壤的pH,也会使土壤的重金属有效态质量分数和酸浸出质量浓度增加,但仅有较低的可能性使2者超标。并且,根据不同的土壤酸碱性质,热解吸工艺对重金属形态转化产生的影响不同。当热解吸工艺放置在添加稳定化药剂后,不影响土壤重金属有效态含量和浸出浓度,并对重金属的形态转化没有影响。2种技术联用时的顺序对重金属稳定化效果的影响较小。本研究可为工程项目实施时的工艺设计提供参考。

In order to study the effect of thermal desorption process placement sequence on the soil heavy metals stabilization, small simulation experiments were conducted on different types of soil samples through heating, and the changes of key soil indicators before and after heating were compared and analyzed. The results showed that when the thermal desorption process was placed before adding stabilizing agents, the soil pH increased, and the available content and the acid leaching concentration of the soil heavy metals also increased.However, there was only a low possibility that both of them exceeded the standard. Moreover, depending on the soil pH, the thermal desorption process had different effects on the transformation of heavy metals. When the thermal desorption process was placed after adding stabilizing agents, the available content and leaching concentration of heavy metals in the soil and the form transformation of heavy metals did not be affected. The impact of heavy metals stabilization was minor when the two technologies were combined. This research can provide references for process design during the implementation of engineering projects.