Estudo das interações e propriedades interfaciais para aplicação da técnica de dispersão química no combate a derramamento de óleo no mar

Abstract

This research aims at evaluating the application of chemical dispersants at oil spills, with focus in a representative Brazilian crude oil with significant share in the country’s offshore production. The crude was characterized, both fresh and weathered, and chemical dispersion efficiency assessed with Corexit EC9500A. The dynamic and equilibrium interfacial tensions were investigated as a function of water salinity and both dispersant and individual surfactants concentrations (DOSS, TWEEN 80 and SPAN 80). The partition coefficients and interfacial rheology parameters were evaluated for different concentrations and conditions. The results indicated that the oil is dispersible only in fresh condition (efficiency = 53%). While DOSS presented a fast adsorption kinetics and an effectiveness (0,50 mN/m) close to Corexit (0,36 mN/m), TWEEN 80 and SPAN 80 showed high viscoelasticity moduli (33,80 and 11,21, respectively), indicating the potential to enhance the stability of interfacial films. A possible interfacial mechanism for surfactants’ action was proposed and the potential to develop optimal formulations when in comparison with the commercial product is identified.