Enhanced Diffusion of Polycyclic Aromatic Hydrocarbons in Artificial and Natural Aqueous Solutions

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• 作者：Philipp Mayer ; Margit M. Fernqvist ; Peter S. Christensen ; Ulrich Karlson ; Stefan Trapp
• 刊名：Environmental Science & Technology
• 出版年：2007
• 出版时间：September 1, 2007
• 年：2007
• 卷：41
• 期：17
• 页码：Mayer, Margit M. Fer
• 全文大小：156K
• 年卷期：v.41,no.17(September 1, 2007)
• ISSN：1520-5851

文摘

Uptake of hydrophobic organic compounds into organismsis often limited by the diffusive transport through a thinboundary layer. Therefore, a microscale diffusion techniquewas applied to determine the diffusive mass transfer of12 polycyclic aromatic hydrocarbons through water, air,surfactant solutions, humic acid solutions, aqueous soil andhorse manure extracts, digestive fluid of a deposit-feeding worm, and root exudates from willow plants. Inmost cases the diffusive mass transfer of PAHs was muchhigher through the tested media than through water, andthe enhancement factors increased with increasinghydrophobicity of the PAHs. The diffusive flux of benzo[a]pyrene was for instance enhanced 74 times through gutfluid of a deposit-feeding worm when compared to water.These findings demonstrate that a wide variety of dissolvedorganic carbon (DOC) at environmental levels can enhancediffusive mass transfer in various transport scenarios.The diffusive uptake of PAHs into sediment dwelling organismsis particularly efficient within the gut and at directcontract with the sediment matrix. Bioremediation mightbe enhanced by the addition of auxiliary agents that enhancediffusive mass transfer. Enhanced diffusion needs alsoto be considered in dynamic transport models and for theoperation and calibration of passive sampling techniques.