表面活性剂对苯并[a]芘在黑炭表面吸附解吸的影响 |
摘要点击 2841 全文点击 1858 投稿时间:2011-05-08 修订日期:2011-12-06 |
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中文关键词 表面活性剂 黑炭 苯并[a]芘 吸附 解吸 |
英文关键词 surfactant black carbon benzo[a]pyrene sorption desorption |
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中文摘要 |
通过静态吸附实验,研究了3种不同类型的表面活性剂(阳离子∶十六烷基三甲基溴化铵, CTAB; 阴离子∶十二烷基苯磺酸钠, SDBS∶非离子,曲拉通100, TX100)对苯并[a]芘(BaP)在黑炭表面吸附解吸的影响.结果表明,3种表面活性剂的存在均会增加BaP在黑炭表面吸附的非线性程度.CTAB的存在可以促进BaP在黑炭表面的吸附同时抑制了BaP的解吸,然而SDBS的存在降低了BaP在黑炭表面的吸附并增加了吸附过程的可逆性.与CTAB和SDBS不同,TX100对BaP在黑炭表面吸附解吸的影响取决于其添加浓度.低浓度的TX100(50 mg·L-1)能够促进BaP在黑炭上的吸附并抑制BaP的解吸,吸附能力参数Kd值(在ce=50 μg·L-1下)从188062 mL·g-1增大到264179 mL·g-1,解吸滞后指数HI从0.44降低到0.39.随着TX100浓度增加到150 mg·L-1和200 mg·L-1,TX100对BaP的吸附表现出抑制作用并能够促进BaP的解吸,Kd值(在ce=50 μg·L-1下)从188062 mL·g-1分别降低到182751 mL·g-1和178730 mL·g-1,解吸滞后指数从0.44分别升高到0.65和0.70.本研究为预测多环芳烃在表面活性剂污染的环境中的分布特征和最终归趋提供了理论依据. |
英文摘要 |
Sorption and desorption of benzo[a]pyrene (BaP) onto black carbon (BC) extracted from sediment were studied in the presence of three types of surfactants (cetyltrimethylammonium bromide, CTAB; sodium dodecylbenzene sulfonate, SDBS; Triton X-100, TX100) to examine the role of surfactants in sorption and desorption. Nonlinearity of the sorption isotherms of BaP increased in the presence of surfactants. CTAB enhanced the sorption capacity and irreversibility of BaP on BC. However, the presence of SDBS reduced the sorption capacity and desorption hysteresis. Unlike CTAB and SDBS, the influence of TX100 on sorption and desorption was concentration dependent. Low levels of TX100 (50 mg·L-1) enhanced BaP sorption and reduced desorption. The sorption capacity parameter Kd value (at ce=50 μg·L-1) increased from 188062 mL·g-1 to 264179 mL·g-1, and the hysteresis index HI decreased from 0.44 to 0.39.When the TX100 concentration increased to 150 mg·L-1 and 200 mg·L-1, TX100 reduced the sorption of BaP to BC and promoted desorption. The Kd value (at ce=50 μg·L-1) decreased from 188062 mL·g-1 to 182751 mL·g-1 and 178730 mL·g-1, respectively, and the HI value increased from 0.44 to 0.65 and 0.70.Our finding can provide more information for predicting the distribution and fate of PAH in the surfactant polluted environment. |
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