鄱阳湖区PAHs的多介质迁移和归趋模拟

为分析鄱阳湖区PAHs(多环芳烃)的多介质迁移和归趋行为,以可获取模型验证数据的BaP(苯并芘)、BaA(苯并蒽)、Chr()、Pyr(芘)、Fla(荧蒽)、Phe(菲)6种典型PAHs为研究对象,采用逸度模型Level Ⅲ,预测和模拟鄱阳湖区环境多介质中PAHs的分布和归趋状况. 结果表明:鄱阳湖区水相中ρ(BaP)、ρ(BaA)、ρ(Chr)、ρ(Pyr)、ρ(Fla)、ρ(Phe)的计算值分别为0.043 3、0.050 9、0.021 4、0.149 0、0.122 0、0.295 0 μg/L,与实测值基本一致. 气相、土壤相及沉积物相中6种PAHs的计算值与实测值吻合较好,模型可靠. 土壤相和沉积物相中PAHs残留量(以n计)占该区总残留量的92.6%,远高于气相和水相. PAHs在鄱阳湖区多介质中的相间迁移通量以气相→土相、水相→沉积物相、沉积物相→水相为主. 鄱阳湖区各介质中高环PAHs主要源于外来污水和外来废气输入,外来污水输入量(以n计)和外来废气输入量分别占59.4%和33.6%. 中环和低环PAHs主要源于当地的废气排放和外来污水输入. 土壤相和沉积物相是鄱阳湖区PAHs主要的汇,由土壤和沉积物的内源释放而可能引起的二次污染应引起重视. 

Multimedia Fate Modeling of PAHs in Poyang Lake Area

A level Ⅲ fugacity model was used to predict and simulate the multimedia distribution and fate of six typical polycyclic aromatic hydrocarbons (PAHs) in the Poyang Lake area. The six typical PAHs included benzopyrene (BaP), benzoanthracene (BaA), chrysene (Chr), pyrene (Pyr), fluoranthene (Fla) and phenanthrene (Phe), which are priority pollutants according to the United States Environmental Protection Agency (US EPA), and whose data could be obtained for validation of the model. The reliability of the model was verified by the coincidence of the calculated and measured concentrations. The results showed that the calculated concentrations of BaA, Chr, Pyr, Fla and Phe in the water were 0.0433,0.0509,0.0214,0.1490,0.1220 and 0.2950 μg/L, respectively, which were in a good agreement with the corresponding measured concentrations. Also, there was generally good agreement between the calculated and measured concentrations of these six PAHs in the air, soil and sediment. PAHs in the soil and sediment accounted for 92.6% of total PAHs in the Poyang Lake area, much greater than those in the air and water. The pathways from air to soil, water to sediment and sediment to water were the main transfer or exchange fluxes between the phases. High-ring PAHs were mainly from the input of exotic wastewater (59.4%) and air (33.6%). Moderate and low-ring PAHs were mainly from the input of local air and exotic wastewater. Soil and sediment were the dominant PAHs sinks in the Poyang Lake area. Much attention should be paid to the secondary pollution caused by the release of soils and sediments.