Wheat Straw Modified with Palmitic Acid as an Efficient Oil Spill Adsorbent

Raw wheat straw was modified to obtain a new oil absorption material, using palmitic acid as the esterifying agent in dimethyl sulfoxide (DMSO) without additional catalysts. The oil absorbency of the esterified wheat straw material towards 0^# diesel reached 24.31 g/g under the following optimum reaction conditions: pretreated wheat straw: palmitic acid weight ratio of 1:10, reaction temperature of 90 °C, and reaction time of 3 h. The chemical composition and structure of wheat straw fiber before and after esterification reaction were compared using Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and scanning electron microscopy (SEM) methods. The results indicate that the esterification reaction was carried out smoothly, and the wheat straw afterwards had lower crystallinity and a rougher surface with more irregular folds. Additionally, the oil sorption capacity, selectivity, and absorption kinetics of the esterified wheat straw were also investigated. The esterified wheat straw showed good potential for converting agricultural residues into efficient cellulosic oil sorbents.