天津地区六六六的归宿和跨界面迁移

以天津市为研究区域，以80年代有机氯农药禁用前为时限，利用稳态非平衡逸度模型估算了稳态条件下六六六的四种异构体在环境各相中的迁移和分布。模型估算结果用同期各主要介质的实测浓度加以验证。结果表明，农业施用和农药厂排放是该地区环境中六六六的主要来源，最大的汇则是土壤和水体沉积物，该地区最主要的界面迁移过程包括大气向土壤的沉降、水体向沉积物的沉降以及气相平流输出等，发生在土壤和沉积物中的降解则是六六六消失的最主要途径。

FATE AND TRANSFER FLUX OF HCHs IN TIANJIN

Based on steady state assumption,the concentrations in various media and the transfer fluxes between adjacent phases of HCHs were modeled using fugacity modeling.The model was validated by comparing the calculated and independently measured concentrations of HCHs in the bulk pha ses. The calculated values agreed well with the observed ones with less than half order of magnitude differences for most compartments.It is indicated that the primary sources of HCHs in the area are agricultural application and wastewater discharged from the major pesticide production enterprises located in Tianjin.Soil and river bottom sediment was the dominant sinks of HCHs.Among all transfer processes,deposition from air to soil and from water column to bottom sediment are the most important, while degradation either in soil or sediment is the key process of HCHs disappearance.