滇池水域双酚A的环境多介质迁移和归趋模拟

Simulation of multimedia transfer and fate of Bisphenol A in Lake Dianchi

以双酚A为研究对象,利用四级多介质逸度模型模拟非稳态非平衡条件下1991-2011年间双酚A在滇池水域水相、表层沉积物相和中层沉积物相中的浓度分布、相间的迁移通量,确定主要迁移过程;结合实测数据,对模型进行可靠性验证;并对常数之外的12个模型参数进行灵敏度分析.结果表明:入滇总量98%的双酚A主要通过水体降解去除,滇池出水去除量和水体残留量共约占1%,余下部分进入沉积物相;沉积物相是残留双酚A最主要的汇,其中,表层沉积物相中双酚A浓度最高,3相中浓度变化趋势受外界输入影响较大;水相→表层沉积物相的迁移为双酚A在滇池的主要迁移过程,其次为表层沉积物相→中层沉积物相;双酚A在水中的降解速率、有机碳分配系数,各环境相中有机碳含量、固相体积比等参数灵敏度较高,对模型的影响较为显著;模型计算浓度与实测浓度吻合较好,表明建立的四级多介质逸度模型适用于滇池水域双酚A环境多介质迁移和归趋模拟.

A multimedia fugacity model （ Level IV） was applied to simulate the concentration distribution and transfer fluxes of Bi- sphenol A （BPA） in three environmental compartments including water, up-sediment, middle-sediment in Lake Dianchi from 1991 to 2011. The reliability of this model was analyzed by comparing modeling results with measured data and the key parameters were selected by means of sensitivity analysis. The study results showed that sediment was the main reservoir of BPA in Lake Dianchi. The highest concentration of BPA was observed in the up-sediment. 98% of the total BPA that discharged into Lake Dianchi was removed by its degradation in water with - 1% was removed by water flow or as residual in sediments. The flux from water to sedi- ment was the main process of migration among different media. The study results also indicated that the degradation rate of BPA in water, organic carbon partition coefficient of BPA, organic carbon content of sediment and solid phase volume ratio had significant influences on the sensitivity of the model. The reliability of the model was verified by the agreement between calculated and meas- ured concentrations. The study showed that the established model was suitable for simulating the multimedia transfer and fate of BPA in the Lake Dianchi.