南京地区PCB52多介质迁移归趋行为模拟及环境风险评价

Simulating the Transfer and Fate and Environmental Risk Assessment of PCB52 in Nanjing

运用多介质逸度模型对PCB52在南京地区空气、水体、土壤和沉积物中的浓度分布与多介质间的迁移、归趋行为进行模拟研究并分析PCB52在研究区域环境多介质间的迁移通量,确定其在环境中的主要迁移过程;结合文献中的监测数据,对模型的可靠性进行验证;对模型的输入参数进行灵敏度分析;通过模拟浓度与实际浓度的对比,表明模型在该地区具有很好的适用性。结果表明,环境系统达到平衡时,PCB52在沉积物中的含量占其在环境系统总含量的96.12%;PCB52从环境系统中的消失途径主要为空气平流输出和空气降解;环境温度和空气平流输入是影响化合物在环境相中浓度分布的最主要因素。此外,PCB52初步的生态风险评价表明其对生态环境未构成严重威胁,但潜在危害仍不容忽视。

A multimedia fugacity model was applied to simulate the concentrations distribution, transfer and fate of PCB52 in air, water, soil and sediment of Nanjing Area. Meanwhile, the transfer fluxes between different compartments were analyzed in order to infer the main transfer process. Moreover, the simulated concentrations in air, soil and sediment were compared to monitoring data for validation purpose. Input parameters of the model were tested and the key parameters were identified using sensitivity analysis method. The reliability of the model was verified by the agreement between calculated and measured concentrations. When the sys- tem reaches equilibrium, sediment compartments were the main reservoirs of PCB52 in Nanjing area because of the mass fraction of PCB52 was 96.12%. The air advection outflow and air degradation were the major elimination routes for PCB52 in Nanjing. The results of sensitivity analysis in this study also indicated that the ternperature and air advection inflow had significant influence on concentrations of PCB52 in various media. The preliminary risk assessment suggested that the PCB52 in the study area might pose tittle harm to the environment, but the latent damage should not be disregarded.