Development and evaluation of solbrax-water nanoemulsions for removal of oil from sand

Abstract

In recent years, surfactants have been used to clean up soils and aquifers contaminated by petroleum and petroleum derivatives. The purpose of this study was to develop and evaluate nanoemulsions for remediation of soil contaminated by petroleum, by using a commercial solvent Solbrax. The nanoemulsions were prepared by the phase inversion temperature (PIT) method, using oil phase Solbrax (a solvent extracted from naphtha with low aromatics content) and a nonionic ethoxylated lauryl ether surfactant. The surfactant concentrations were varied from 10 to 12 wt% and the oil phase was varied from 5 to 20 wt%. A 23 factorial experimental design with center point run was used to evaluate the soil washing process, varying time, temperature, and shear rate of the system. The results show that the most efficient system (with 90% efficiency) was that using the nanoemulsion containing 5 wt% of Solbrax and 12 wt% of surfactant after four hours of washing, on 240 rotation·min -1 of shear rate and at a temperature of 318 K. © 2014 Priscila F. Oliveira et al.