Aqueous vapor extraction: a previously unrecognized weathering process affecting oil spills in vigorously aerated...

Simple evaporation of spilled oil is usually thought to be restricted to the smaller hydrocarbons (<15 carbons). We show that aeration of oil in water, at 22 degrees C, substantially extends this evaporation, leading to the loss of alkanes up to at least hexatricosane (nC36) and of polycyclic aromatic hydrocarbons with at least four rings (e.g., chrysene and its alkylated forms). This phenomenon is apparently related to steam distillation and should be considered as an important candidate pathway to explain the observed weathering of oil spilled from the OSSA II pipeline into the Río Desaguadero on the Bolivian Altiplano (approximately 3700 m), which occurred during a very turbulent flood.