Modeling the partitioning of BTEX in water-reformulated gasoline systems containing ethanol

Mechanisms Affecting the Infiltration and Distribution of Ethanol-Blended Gasoline in the Vadose Zone

“…Isooctane was substituted for gasoline in these experiments to minimize interference of the more soluble gasoline components with the UV absorbance technique used to quantify ethanol concentrations. The partitioning properties of ethanol in isooctane and gasoline are very similar (5). Fluorescein was also found to interfere with the analytical methods.…”

“…The hydrophilic nature of ethanol causes it to almost completely partition into the aqueous phase (5). As ethanol concentrations in the aqueous phase increase, the solubility of BTEX (benzene, toluene, ethylbenzene, and xylenes) and other gasoline components also increase; a phenomenon termed cosolvency.…”

Analytical model for BTEX natural attenuation in the presence of fuel ethanol and its anaerobic metabolite acetate

“…Therefore the presence of ethanol and ethanol-derived acetate in groundwater can contribute to longer BTEX plumes (Ruiz-Aguilar et al, 2002;Corseuil et al, 2011) increasing the risk of human exposure ). These observations have been corroborated by laboratory studies (Corseuil et al, 1998;Da Silva and Alvarez, 2002;Cápiro et al, 2007Cápiro et al, , 2008, field research (Ruiz-Aguilar et al, 2002;Corseuil et al, 2011) and modeling studies (Heermann and Powers, 1998;Mcnab et al, 1999;Molson et al, 2002;Gomez et al, 2008;Alvarez, 2009, 2010). Nevertheless, the intensity of these effects can be system specific, which underscores the need for simple models that facilitate preliminary risk assessment and evaluate the potential performance of natural attenuation.…”

Peer Reviewed: Will Ethanol-Blended Gasoline Affect Groundwater Quality?

“…With a sufficiently large amount of ethanol in a localized subsurface environment, gasoline and water become completely miscible with each other and merge into a single phase (see sidebar). Although this might occur following a spill of neat ethanol into petroleum-contaminated soil at a terminal, ethanol concentrations (m15% by volume in the aqueous phase) in groundwater near the site of an RFG spill are expected to be much lower than the 80% by volume concentrations in the aqueous phase that is required to create a single phase (10,11). Aqueous-phase concentrations of ethanol that leach from an RFG or oxyfuel spill could also be high enough to increase the groundwater concentrations of individual chemical species equilibrated with the gasoline.…”