Surface films : do they influence the effectiveness of oil spill chemical dispersants as studied in a wave tank facility?

Abstract

Lab basins and wave tanks have unnatural boundaries (walls) that provide an ideal environment for surface film formation on seawater. Surface films form from natural surfactants in oil and dispersant overspray when applied to seawater. The adsorption process of selected crude oils, Arabian Light (ALC) and Alaskan North Slope (ANS) on static seawater in a lab basin was demonstrated to follow diffusion-controlled short time limit adsorption kinetics. The process of crude oil spreading on the surface of the basin seawater was affected in the presence of surface films as shown using kinetic models. ANS dispersed in the dynamic wave tank seawater with and without a surface film (dispersant overspray) was evaluated using kinetic models. It was found that oil dispersed in wave tank seawater, in the presence of dispersant overspray, influences oil dispersant effectiveness and produced confounding outcomes that are an unnatural model of dispersed oil fate and effects.