某退役溶剂厂有机物污染场地燃气热脱附原位修复效果试验

热脱附技术一般用于土壤中有机物的异位修复,然而对于受有机物污染较深土壤的原位修复却鲜有报道.本文以某退役溶剂厂土壤中苯、氯苯和石油类为目标污染物,运用燃气热脱附技术进行原位修复.本文介绍了燃气热脱附技术的工艺设计流程,针对场地目标污染物进行燃气热脱附的工程化试验,结果显示热脱附处理后土壤中苯、氯苯和石油类最高去除率接近100%.本文还探讨了温度、停留时间、土壤含水率和土壤质地对热脱附效率的影响,发现在温度和停留时间相同情况下,含水率较小、孔隙率较大的粉砂土热脱附效果更好.试验表明,燃气热脱附原位修复技术处理场地挥发性有机污染物效果良好,可以进行大规模的实际运用.

In-Situ remediation of organics-contaminanted site by gas thermal desorption at a retired solvent plant

Thermal desorption technique is generally used for the ex-situ remediation of volatile organic compounds-polluted soil. However, there are few reports on in-situ remediation of organics-contaminated soil. In this study, benzene, chlorobenzene and petroleum contaminated soil from a decommissioned solvent factory was treated with in-situ gas thermal desorption technique. The specific design of gas thermal desorption technology was discussed as well. The maximum removal rates of benzene, chlorobenzene and petroleum were up to 100% after thermal desorption. In addition, the influences of temperature, retention time, soil moisture and soil type on thermal desorption efficiency were also investigated. Under the same temperature and retention time, organic pollutants in the silt sand soil with lower moisture and higher porosity were desorbed easily. The results indicate that the in-situ gas thermal desorption technology can be used to treat the site contaminated by volatile organic pollutants and should be applied in large-scale practice.