Graphene aerogel - Recovery of heavy crude oil from contaminated sand

Graphene aerogel (GA) is widely studied in the oil contamination field today due its excellent adsorption properties like superhydrophobicity, high surface area, light-weight and high reusability. This study presents the effects of oil viscosity, agitation speed and oil-sand wettability on the adsorption efficiency of heavy crude oil from contaminated sand using GA. Results showed that the adsorption kinetics were best fitted with the Langmuir isotherm and pseudo-second order kinetic model indicating that the adsorption system was a two-stage process, and a monolayer adsorption route. The fitted pseudo-second order kinetic model showed that the adsorption equilibrium decreased from 12354 mg/g to 6180 mg/g with increased in crude oil viscosity from 80 cst to 380 cst, at oil-sand of wettability 4% (wt.), agitation speed of 50 rpm and room temperature of 27 °C. In addition, the highest adsorption capacity was experimentally found to occur at 4% (wt.) oil-sand wettability and agitation speed of 70 rpm, with an oil (180 cst) adsorption capacity of 11736 mg/g. On the other hand, Thus, this study showed that the GA is a promising material to improve the traditional batch extraction to remove and recover heavy crude oil from oil-wet sands.