【摘要】 利用长江口滨岸水环境中颗粒相与溶解相多环芳烃的实测浓度,获取了多环芳烃化合物在颗粒物-水相间的分配系数Kp.结果表明,分配系数Kp值在507~10179 L/kg之间,枯季高于洪季,随多环芳烃环数的增加而增大;Koc值与辛醇-水分配系数Kow之间存在较好的线性自由能关系(枯季R2=0.82,洪季R2=0.68),推断出长江口滨岸颗粒物亲脂性较差,对多环芳烃的吸收能力相对较弱.长江口滨岸各采样点多环芳烃化合物的lgKoc值均超过了经典平衡分配模型的预测值上限,多环芳烃两相分配行为不受颗粒物浓度、粒径及上覆水盐度、溶解态有机碳的控制(R2<0.1),表现出主要受POC及非均一性混合物PSC共同影响的特点;扩展后的含PSC相的颗粒物-水相分配模型较为准确地模拟了lgKow<6的多环芳烃化合物野外原位分配过程.更多还原

【Abstract】 Based on polycyclic aromatic hydrocarbons（PAHs） field data of particle phase and dissolved phase,partition coefficients K_p in particle-water interface from the Yangtze Estuarine and nearby coastal areas were obtained.The results show partition coefficients of PAHs in dry season were higher than those in flood season,and all of them ranged from 507（L/kg） to（10?179） （L/kg）,increasing with the rise of PAH compounds.The linear free-energy relationship coefficients between K_oc value and octanol-water partition coefficients K_ow in dry season and flood season were 0.82 and 0.68,respectively. These relationships inferred that suspended particle matters in the Yangtze Estuarine and coastal areas had weakly lipophilic characteristics and adsorption ability.lgK_oc values of PAH compounds in the different sampling sites were higher than the upper limit value predicted by the classic equilibrium partition model.The partition processes of PAHs were not controlled by concentrations of suspended particle matters,particle grain sizes,overlying water salinity and dissolved organic carbon（R²<0.1）,but influenced by particle organic carbon and heterogeneous mixtures of particle soot carbon.The expanded partition model which included soot partitioning could well predict in situ partition processes of PAH compounds whose octanol-water partition coefficients lgK_ow was lower than 6.更多还原