Kinetic and thermodynamic studies for the sorptive removal of crude oil spills using a low-cost chitosan-poly (butyl acrylate) grafted copolymer

In this study, a low-cost chitosan (CS) marine biopolymer was grafted with oleophilic butyl acrylate (ButA) monomer for the sorptive removal of crude oil spills from the water surface. Fourier-transform infrared spectroscopy and scanning electron microscope analysis were used for investigating the chemical structure as well as the surface morphology of CS-g-poly (ButA) copolymer. The dependency of oil-sorption capacity on parameters such as sorption time, crude oil concentration, sorbent dosage, agitation rate, and sorption temperature was considered. The empirical equilibrium data were verified using different isotherm models. The results clarified that both Langmuir and Freundlich isotherm had an exceptional agreement with the laboratory data. The maximum monolayer adsorption capacity was 27.7 g/g for native CS, while it reached a maximum value 83.3 g/g for the grafted copolymer. The kinetic characteristics of the adsorptive performance were undertaken by practising several models. The results validated that the sorption regarded the pseudo-second-order model and film-diffusion-controlled mechanism. Besides, the thermodynamic parameters endorsed the process to be endothermic, favorable and spontaneous. The gained results advocate the excellent potential of the developed chitosan grafted copolymer as oil-sorbent materials for oil spill clean-up applications.