环境化学
夏星辉,孟丽红,呼丽娟.苯并(a)芘在黄河水体不同粒径颗粒物上的表面吸附和分配作用特征[J].环境科学学报,2006,26(2):269-274
苯并(a)芘在黄河水体不同粒径颗粒物上的表面吸附和分配作用特征
- Adsorption and partition of benzo(a)pyrene on solids with different particle size from the Yellow River
- 基金项目:国家自然科学基金资助项目(No.40201046和No.40571138)
- 夏星辉
- 北京师范大学环境学院/水环境模拟国家重点实验室, 北京 100875
- 呼丽娟
- 北京师范大学环境学院/水环境模拟国家重点实验室, 北京 100875
- 摘要:模拟实验研究了苯并(a)芘在黄河水体不同粒径颗粒物上的吸附作用,重点探讨了颗粒物粒径对苯并(a)芘的表面吸附和分配作用的影响.结果表明:(1)苯并(a)芘在黄河水体颗粒物上的吸附符合表面吸附-分配作用复合模式(2)苯并(a)芘在粒径d≥0.025 mm颗粒物上的吸附以表面吸附为主,表面吸附对吸附的贡献在8.7%至82.4%之间;当苯并(a)芘液相平衡浓度为0~8.87μg·L-1时,其在粒径0.007 mm≤d<0.025 mm颗粒物上的吸附以表吸附作用为主,当液相平衡浓度大于8.87μg·L-1时,吸附以分配作用为主;苯并(a)芘在粒径d<0.007 mm颗粒物上的吸附以分配作用为主;(3)苯并(a)芘在不同粒径颗粒物上的表面吸附对总吸附的贡献大小顺序为:(d≥0.025 mm)>(0.007 mm≤d<0 025 mm)>(d<0.007 mm);(4)苯并(a)芘在不同粒径颗粒物中的分配系数与有机质含量呈线性相关,其标化分配系数Koc约为1.2×105L·kg-1.
- Abstract:Experiments have been carried out to study the sorption of Benzo(a)pyrene on particles of the Yellow River; effects of particle size on adsorption and partition of Benzo(a)pyrene have been investigated. Several significant results have been obtained from the study: (1) Isotherms of Benzo(a)pyrene can be fitted with the Dual Adsorption-Partition model under different particle size; the measured values of the adsorption and partition are in accord with the theoretical values of the Dual Adsorption-Partition model. (2) When the particle diameter is d≥0.025 mm, the adsorption is predominant in the sorption of Benzo(a)pyrene, which accounts for 68.7%~82.4% of the sorption. For the particles with the size of 0.007 mm ≤d< 0.025 mm, the adsorption is predominant when the equilibrium concentration of Benzo(a)pyrene is 0~8.87μg·L-1 in water phase; the partition is predominant when the equilibrium concentration of Benzo(a)pyrene is higher than 8.87μg·L-1 in water phase. When the particle diameter is d< 0.007 mm, the partition is predominant. (3) In point of particle size, the contribution of adsorption to sorption follows the order: “d≥0.025 mm” > “0.007 mm<d< 0.025 mm” > “d< 0.007 mm”. (4) The partition coefficients of Benzo(a)pyrene in solids with different particle size are linearly correlated with the organic content, and the Koc of Benzo(a)pyrene is about 1.26×105L·kg-1.
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