How Redox Conditions and Irradiation Affect Sorption of PAHs by Dispersed Fullerenes (nC60)

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• 作者：Thorsten H眉ffer ; Melanie Kah ; Thilo Hofmann ; Torsten C. Schmidt
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2013
• 出版时间：July 2, 2013
• 年：2013
• 卷：47
• 期：13
• 页码：6935-6942
• 全文大小：314K
• 年卷期：v.47,no.13(July 2, 2013)
• ISSN：1520-5851

文摘

Surface properties, dispersion state, and sorption behavior of carbon-based nanomaterials will change after being released into the environment. To study these processes, five different scenarios were considered to probe the impact of changes in surface properties of dispersed fullerenes (nC60) on their sorption potential due to irradiation and presence of oxygen. Sorption isotherms of pyrene by nC60 were determined at environmentally relevant concentrations applying a passive sampling method. Isotherms of all dispersion scenarios were best fit with the Dubinin鈥揂shthakov model. Sorption was strongest for nC60 kept under anoxic condition. Both the presence of oxygen and irradiation significantly decreased the sorption capacity of nC60, while commercially available polyhydroxy fullerenes had the smallest sorption. In addition, competition for sorption sites was never observed in multiple sorbate experiments with four polycyclic aromatic hydrocarbons at small concentration. A strong relationship between sorption coefficients and hydrophobic properties of sorbates suggests that hydrophobic interactions are of major importance. The results emphasize that aging of released fullerenes results in a reduced strength of interactions with nonpolar compounds and, thus, reduces the impact on the environmental transport of hydrophobic pollutants.