我国二噁英污染水平和环境归趋模拟

Pollution Situation and Environmental Fate of PCDD/Fs in China

运用LevelⅢ逸度模型,研究了我国环境介质中二噁英的平均浓度水平和迁移规律.比较不同尺度下的模拟结果表明,LevelⅢ逸度模型可以应用于较大尺度的研究.数据显示,虽然我国二噁英排放总量较大,但是环境介质中TEQ(指二噁英毒性当量质量浓度)平均值仍处于较低水平,大气中TEQ平均值仅为4.26～15.10fgxA3,土壤中TEQ平均值为0.0135～0.1150pgg,沉积物中TEQ平均值为0.445～2.300pgg.达到稳态时二噁英的外界输入影响较大,且主要的迁移过程是从大气到土壤.

Levels and fates of dioxins in the environment are simulated by the level Ⅲ fugacity model,based on the dioxin release inventory of China.Comparing the results at different scales,we find that the level Ⅲ fugacity model can be used for large scale simulation.It shows that dioxin concentrations in environmental media are still fairly low,although the total release amount of dioxins in China is higher than that in most other countries.The average TEQ concentrations in air,soil and sediment are 4.26-15.10 fg/m3,0.0135-0.1150 pgxA 1/g and0.445-2.300p gxA1ectively.The inflow of dioxins through the atmosphere is the major contributor instead of the local sources,and soil is the main sink of dioxins.