黄浦江底泥对多环芳烃吸附机理的研究

STUDY ON ADSORPTION MECHANISM FOR PAHs ONTO SEDIMENTS IN HUANGPU RIVER

本文主要介绍黄浦江底泥对以蒽为代表性物质的多环芳烃的吸附研究.着重探讨其吸附机理,在实验条件下,黄浦江底泥对蒽的吸附属多分子层吸附,可用de Boer-Zwikker公式所表示的极化模型较好地描述,这表明原描述非极性气相分子在极性吸附剂上吸附的多分子层极化模型可应用于稀溶液中溶剂化蒽分子在极性吸附剂上的吸附过程.本研究认为吸附等温线上出现阶梯状形式是由于蒽-甲醇分子的溶剂化作用及底泥颗粒的表面不均匀性所致;未参与溶剂化作用的甲醇分子与溶剂化蒽分子间存在竞争吸附,这一结果预示了其它有机物对多环芳烃在底泥上的竟争吸附作用.

It is introduced that anthracene, as the model compound of PAHs , was adsorbed onto the sediments in Huangpu river. The emphasis was laid on discussion of adsorption mechanism. Under the conditions of the experiments, the adsorption for anthracene onto sediment in Huangpu river belongs to multi-molecular layer adsorption and can be well described by de Boer-Zwikker equation for polarization model. It shows that the model for describing the adsorption of unpolar gas molecules onto polar adsorbents can be applied in the adsorption process of anthracene-methanol solvolytes onto polar adsorbents. It was believed in this study that the stepwise adsorption isotherm curves are caused by anthracene-methanol solvolytes and uneven surface of sediment particles. There is a competitive adsorption onto sediments between non-solvolytic methanol molecules and anthracene-methanol solvolytes. This results could predict the existance for competitive adsorption of other organic compounds with anthracene on sediments.