Removal of crude oil from aqueous medium by sorption on hydrophobic corncobs: Equilibrium and kinetic studies

Crude oil released to the marine environment through accidental spillage or drainage from land causes serious damage to the environment and marine life. The treatment of an oil spill remains a challenge to environmental scientists. Sorption is a popular technique for clean-up of oil spills. In this study, corncobs, which are an abundant, biodegradable agricultural waste, were treated with acetic anhydride to increase their hydrophobic properties and improve their sorption effectiveness in aqueous environments. The crude oil absorption behaviour has been discussed, and the employed kinetic models suggest that the sorption process occurs via a surface reaction and intraparticle diffusion mechanism. Equilibrium isotherm data were analysed using the Langmuir and Freundlich isotherms. Based on the regression coefficients, the Langmuir isotherm provided the best fit to the experimental data. The maximum monolayer sorption capacities were 0.0768 mg/g and 0.0043 mg/g for the acetylated and raw corncobs, respectively. The results presented and discussed in this study indicated that acetylated corncobs are suitable sorbents with the potential for further development for oil spill treatment.