关键词: 土壤, 有机污染, 修复, 异位热脱附, 设备优化

Abstract: 16 typical ex-situ indirect thermal desorption projects in 12 provinces in China were investigated. The application characteristics of ex-situ indirect thermal desorption technology were analyzed. The results showed that the target pollutants of ex-situ indirect thermal desorption remediation mainly include benzene, chlorinated hydrocarbons, polycyclic aromatic hydrocarbons, pesticides and petroleum hydrocarbons, for a total of five types. The maximum exceedance of pollutants multiples was 7.60~4 409.09. The maximum thermal desorption temperature ranged from 350 to 750 ℃, the thermal desorption residence time of less than 30 min accounted for 94% of the projects, the comprehensive cost of thermal desorption repair was 734~1 400 yuan per square meter, the average value was 1 210 yuan per square meter. At the same time, the operation problems of thermal desorption equipment in engineering applications were identified, and it was found that the running stability of thermal desorption equipment was poor, which restricted the processing capacity. And the energy utilization efficiency of thermal desorption system was low, which affected the processing cost. It was necessary to further strengthening the research of thermal desorption process heat and mass transfer mechanism, improving the level of equipment integration and standardization and improving the energy utilization efficiency.

Key words: soil, organic pollution, remediation, indirect thermal desorption, equipment optimization