河流环境持久性有机污染物归宿的动态逸度模型

运用逸度方法构建了依赖于温度的、模拟持久性有机污染物(POPs)在河流环境中长期变化的动态归宿模型,其中逸度容量、污染物的转化速率、传递系数等模型参数的计算与温度有关.为了检验模型的合理性,以辽河下游为研究区域,对水体和沉积物中的γ-HCH进行了模拟计算.结果表明:逸度容量的变化与温度负相关,速率系数则相反.在模拟温度范围内(273～298K),-γHCH在空气、水和沉积物中的逸度容量分别减少了8.4%、89.7%和89.7%,转化速率系数分别增加了0.69、22.0和4.5倍;气-水界面的挥发和水-沉积物界面的扩散速率系数分别增加了7.9和1.6倍.模型计算值与实测值吻合较好,最大偏差为5.6倍,表明该模型用于残留POPs的长期预测是可行的.

Dynamic Fugacity Model for Describing the Fate of Persistent Organic Pollutants in the River

Dynamic model depending on temperature with fugacity approach is formulated which describes the fate of Persistent Organic Pollutants (POPs) in a river. The fugacity capacity, the degradation rate and transfer coefficients of pollutants are depending on temperature in the model. The model is illustrated by calculating the fate of gamma-HCH in Liao River. The results show that from 273K to 298K, the fugacity capacities in air, water and sediment of gamma-HCH are respectively reduced in 8.4%, 89.7% and 89.7%. However, in the same range of temperature, the degradation rate coefficients in air, water and sediment, and volatilization and diffusion rate coefficients of gamma-HCH are increased in 0.69, 22.0, 4.5, 7.9 and 1.6 times, respectively. The calculated value agree well with the field observed value in the order of magnitude, which shows that the model is appropriate for simulating the fate of POPs in a long time.