有机物和重金属污染土壤水泥窑协同处置及应用研究

Study on the Collaborative Disposal and Application of Organic and Heavy Metal Polluted Soil in Cement Kilns

以江苏徐州某土壤修复治理项目为例,探究了水泥窑协同处置技术的工程应用效果。项目重金属及有机污染土壤以3.23%的投加量添加,可满足入窑重金属限制要求。其中,有机及复合污染土壤从窑尾高温段进料,有机物最终挥发分解,得以全部去除,去除率达100%。重金属污染土壤从生料口进料,重金属浸出含量均低于标准限值,重金属在熟料中得到有效固化及稳定化。工程实践应用表明:水泥窑协同处置通过充分考虑投加污染土重金属含量及其他入窑材料中重金属带入量,严格控制配比和投加速率,形成的熟料及最终水泥均满足水泥相关质量规定;水泥窑协同处置可对原场地污染物进行彻底清除,最终实现对污染物风险永久的消除,不影响后续开发建设过程,避免重复施工导致资源的浪费;水泥窑协同处置实现了污染土壤资源化利用,解决了其他异位土壤修复模式面临的修复后土壤终端消纳问题;水泥窑协同处置的重金属的固化稳定化的持久性相关研究较少,后续需进一步完善补充。此工程案例的顺利实施,明确了水泥窑协同处置过程中的关注点,为我国污染土壤水泥窑资源化利用提供了有效的工程案例参考。

Taking a soil remediation project in Xuzhou,Jiangsu Province as an example,the engineering application effect of cement kiln collaborative disposal technology was explored.The heavy metal and organic contaminated soil in this project can be added at a dosage of 3.23%,which can meet the requirements for heavy metal restrictions when entering the kiln.Among them,organic and composite contaminated soil is fed from the high-temperature section of the kiln tail,and the organic matter is ultimately volatilized and decomposed,which can be completely removed,with a removal rate of 100%.Heavy metal contaminated soil is fed from the raw material inlet,and the leaching content of heavy metals is below the standard limit.Heavy metals are effectively solidified and stabilized in the clinker.Through practical engineering applications,it has been shown that the collaborative disposal of cement kilns can meet the requirements of relevant standards by fully considering the content of heavy metals in contaminated soil and the amount of heavy metals brought in from other kiln materials and strictly controlling the ratio and acceleration rate of feeding.The physical and chemical properties of the produced cement clinker and cement products can all meet the requirements of relevant standards;The collaborative disposal of cement kilns can completely remove pollutants from the original site,ultimately achieving permanent elimination of pollutant risks,without affecting the subsequent development and construction process,and avoiding resource loss caused by secondary construction;The collaborative disposal of cement kilns has achieved the resource utilization of polluted soil and solved the problem of post remediation soil terminal consumption faced by other heterotopic soil remediation models;There is limited research on the durability of solidification and stabilization of heavy metals in the collaborative disposal of cement kilns,and further improvement and supplementation are needed in the future.The smooth implementation of this engineering case has clarified the key points in the collaborative disposal process of cement kilns,providing effective engineering case references for the resource utilization of cement kilns in polluted soil in China.