PAHs污染土壤的热修复可行性

Feasibility of thermal remediation of soil contaminated with PAHs

以某煤制气厂污染场地中16种US EPA优先控制多环芳烃(Σ16 PAHs)为目标污染物进行了热修复批量实验和可行性实验。热修复批量实验结果表明,当热修复温度为400℃、加热时间为8 h时,土壤中的Σ16 PAHs去除率达99.9%。热修复可行性实验选择重污染、中污染和轻污染土壤以400℃作为目标温度,恒温72 h进行实验。热修复前后不同程度污染土壤的Σ16 PAHs的总去除率均可达到99.9%,但重污染土壤浓度非常高,部分苯并类物质未达到修复目标值,需进一步延长加热时间或提高加热温度保证达到修复目标值。土壤土工参数影响分析结果表明,热修复后土壤颗粒粒径呈增大趋势,土壤稳定性、抗压强度均增强。此外,土壤中可溶性盐含量增多,盐渍化程度增大。

Batch experiments and feasibility study of thermal remediation were conducted for soils contaminated with the US EPA 16 priority polycyclic aromatic hydrocarbons （Σ16 PAHs）. The results of batch experiment indicated that the removal efficiencies of Σ16 PAHs reached 99.9% after thermal treatment for 8 h at 400 ℃. The feasibility study experiments were carried out with a target temperature with 400 ℃ for 72 h. The total removal efficiencies of Σ16 PAHs reached 99.9% as well, however, several contaminants of concern among the Σ16 PAHs concentrations exceeded the remediation cleanup values, especially those compounds in the benzo group. The soil particle size, soil stability and compressive strength increased after the thermal remediation based on the analysis between soil parameters before and after treatment. The soluble salt content increased post thermal remediation, indicating an increase in the soil salinization.