多环芳烃在岩溶地下河表层沉积物-水相的分配 |
摘要点击 3377 全文点击 1825 投稿时间:2015-03-27 修订日期:2015-07-01 |
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中文关键词 岩溶地下河 多环芳烃 影响因素 分配 分配系数 |
英文关键词 karst underground river polycyclic aromatic hydrocarbons impact factor partition partition coefficients |
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中文摘要 |
利用实测老龙洞地下河水中和沉积物中多环芳烃(polycyclic aromatic hydrocarbons, PAHs)的实际浓度,获取了溶解相-沉积物中PAHs的分配系数Kp值. 研究了老龙洞地下河PAHs在水相和沉积物中的质量浓度变化及其在水相和沉积物间的分配. 研究结果表明水相和沉积物中PAHs质量浓度分别为81.5~8089 ng ·L-1,平均值(1439±2248) ng ·L-1和58.2~1051 ng ·g-1,平均值(367.9±342.6)ng ·g-1; PAHs组成均以2~3环为主,但沉积物中明显富集高环PAHs. 沉积物-水相Kp值分布在55.74~46067 L ·kg-1范围内,随PAHs环数的增加而增大. 沉积物-水相中实测的有机碳分配系数(lgKoc)大部分高于预测值上限,PAHs强烈吸附在沉积物上. lgKoc与正辛醇-水分配系数(lgKow)呈较好的线性自由能关系(R2=0.75),但其斜率小于1,推测地下河沉积物对PAHs化合物的吸收能力较差. |
英文摘要 |
Based on polycyclic aromatic hydrocarbons (PAHs) field data of dissolved phase and sediment phase, partition coefficient Kp in sediment-water interface from Laolongdong underground river was obtained. The concentration of PAHs in water and sediment and partition coefficient Kp in sediment-water interface were studied. The results showed PAHs concentrations were 81.5-8089 ng ·L-1with a mean value (1439±2248) ng ·L-1 in water and 58.2-1051 ng ·g-1 with an average (367.9±342.6) ng ·g-1 in sediment. The dominant PAHs were 2-3 rings PAHs in water and sediment. However, high rings PAHs obviously enriched in the sediment. Partition coefficients varied from 55.74 to 46067 L ·kg-1 in sediment-water interface, increasing with the rise of PAH compounds. All the organic carbon partition in sediment-water interface were higher than predicate values based on typical model of equilibrium distribution indicated that PAHs were strongly adsorbed in sediment. The linear free-energy relationship coefficient between Kocvalue and octanol-water partition coefficient Kow was 0.75, but the slope was lower than 1, indicating that sediment in Laolongdong underground river had weakly lipophilic characteristics and adsorption ability for PAHs. |
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