Natural aluminosilicate clay obtained from south-eastern Nigeria as potential sorbent for oil spill remediation

Abstract

Few reports exist on the use of natural inorganic sorbents such as clays compared to organic biomass materials for crude oil sorption. Also, the mechanistic kinetic, isotherm and thermodynamics have seldom been discussed in the few clay oil sorption studies available. This work evaluated the use of Natural Clay (NC) for removal of crude oil from solution. The sorbent was characterized by the Fourier transform infrared, scanning electron microscope, X-ray diffraction, X-ray fluorescence and Brunauer-Emmett-Teller surface area analyzer. The chemical oxide composition revealed SiO2 (53.1%) and Al2O3 (19.8%) as major components of NC and cation exchange capacity of 76.1 mEq/100 g. The Langmuir model presented the best fit with higher R2 of 0.981 and lower Sum square error (SSE) of 0.21 compared to the Freundlich and Tempkin isotherm. The pseudo-first order model was found to be applicable compared to the pseudo-second order kinetic analysis, with intra-particle diffusion mechanism involved in the removal process. Thermodynamics revealed a spontaneous, endothermic and physical sorption of crude oil on NC. The sorption capacity of NC for crude oil was found to be higher than most sorbents reported in literature. NC showed good regeneration and reusability for crude oil removal using n hexane after three cycles of sorption-desorption experiment The study indicated enormous potentials of NC as low cost sorbent for oil spill treatment.