Mopping of crude oil and some refined petroleum products from the environment using sawmill factory waste: adsorption isotherm and kinetic studies

Abstract

The oil (crude oil, diesel and kerosene) sorption capacity, sorbed oil recoverability and retainability by sawdust was determined under the same experimental condition and compared with that of a standard. The result of the study shows that the sawdust has lesser oil sorption capacity and sorbed oil recoverability than the standard, but higher sorbed oil retainability than the standard. Sawdust sorbed per unit mass 5.50g of crude oil, 4.50g of diesel and 4.20g of kerosene while the standard sorbed per unit mass 11.50g of crude oil, 10.35g of diesel and 8.20g of kerosene. Sorbed oil recovered from sawdust and standard are 9.67g of crude oil, 8.40g of diesel, 6.50g of kerosene and 2.90g of crude oil, 2.50g of diesel and 2.90g of kerosene respectively. 2.60g, 2.00g and 1.30g of sorbed crude oil, diesel and kerosene were retained by a unit mass of sawdust while 1.83g, 1.94g and 1.70g of sorbed crude oil, diesel and kerosene were retained by a unit mass of the standard. Adsorption isotherm and kinetic studies shows that the sorption process of crude oil, diesel and kerosene onto sawdust is by Langmuir model and intraparticle diffusion and liquid film diffusion mechanism were parts of the rate determining steps. Sawdust could be employed to clean oil spill on land and aqueous environment. Sawdust is not a very effective oil spill clean-up sorbent, but can be useful when oil recovery is not required but disposal after oil spill clean-up.

Keywords: Sawdust, crude oil, adsorption kinetics, oil sorption capacity, sorbed oil recoverability, adsorption isotherm