Biosurfactant- and Biodegradation-Enhanced Partitioning of Polycyclic Aromatic Hydrocarbons from Nonaqueous-Phase Liquids

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• 作者：Marta Garcia-Junco ; Cesar Gomez-Lahoz ; Jose-Luis Niqui-Arroyo ; and José ; -Julio Ortega-Calvo
• 刊名：Environmental Science & Technology
• 出版年：2003
• 出版时间：July 1, 2003
• 年：2003
• 卷：37
• 期：13
• 页码：2988 - 2996
• 全文大小：127K
• 年卷期：v.37,no.13(July 1, 2003)
• ISSN：1520-5851

文摘

A study was conducted on the effect of two differentbiological factors, microbial surfactants and biodegradation,on the kinetics of partitioning of polycyclic aromatichydrocarbons (PAHs) from nonaqueous-phase liquids(NAPLs). The effect of rhamnolipid biosurfactants onpartitioning into the aqueous phase of naphthalene, fluorene,phenanthrene, and pyrene, initially dissolved in di-2-ethylhexyl phthalate (DEHP) or 2,2,4,4,6,8,8-heptamethylnonane(HMN), was determined in multiple-solute experiments.Biosurfactants at a concentration above the CMC enhancedthe partitioning rate of fluorene, phenanthrene, andpyrene but were ineffective with naphthalene. Enhancementof partitioning was also observed in the presence ofsuspended humic acid-clay complexes, which simulatedthe solids often present in the subsurface. Biosurfactantssorbed to the complexes modified PAH partitioning betweenthe NAPL and these solids, increasing the fraction of solid-phase PAH. Biodegradation-driven partitioning wasestimated in mineralization experiments with phenanthreneinitially present in HMN and three representative soilbacterial strains, differing in their potential adherence tothe NAPL. In the three cases, the rates of mineralization werevery similar and significantly higher than the abiotic rateof partitioning. Our study suggests that in NAPL-polluted sites,partitioning of PAH may be efficiently enhanced by insitu treatments involving the use of biosurfactants andbiodegradation.