机械通风法处理土壤中氯代烃的修复效果研究

Removal of Chlorinated Hydrocarbons from Soil by Mechanical Soil Aeration:Evaluation of Soil Remediation

机械通风法是一种操作简单、效果好、成本低廉的土壤修复技术,特别适合大型挥发性污染场地的土壤修复。为了解该技术对不同挥发性污染物的去除效果,文章选取了国内一大型氯碱化工遗留场地,采用机械通风技术进行了现场修复中试。结果表明,该修复技术对于土壤中的挥发性有机污染物具有很好的去除效果,经修复后土壤中各种污染物的去除率可达90%以上,基本能达到该场地土壤污染物的修复目标值要求。土壤中污染物的挥发过程满足幂函数y=A×e(-x/B)+y0的形式,修复效果明显。结果还表明,污染物浓度对其挥发有较大的影响,浓度越高,挥发速率越快,且污染物的挥发速率与蒸汽压成正比。该研究成果将对我国开展大型挥发性污染场地的土壤修复工作提供理论基础和技术支持。

To investigate effectiveness of mechanic soil aeration, a contaminated soil remediation method, applied to removal of different volatile organic compounds, a field experiment on a pilot scale was conducted on an abandoned land plot which used to be a chlor-alkali factory. Results of the experiment showed that mechanic aeration of soil contaminated by volatile organic compounds could attain rather high total removal rates of more than 90%; and the volatilization process could be divided into two phases which were described by a function similar to y=Axe-aB）＋yo. Besides, it was also showed that higher the concentration of contaminates, faster the evaporation rate. Evaluation of the method suggested that results of the pilot experiment can be extensively used applied to larger sites polluted by volatile organic compounds.