In the present study, yellow horn shell residues treated by ionic liquid (IL) were prepared for oil removal from water. Scanning electron microscope (SEM) analysis was applied to represent the effects of IL-treatment on this new cellulosic biosorbent. Furthermore, the comprehensive sorption capacities of the shell residues for five types of oils in pure oil and oily water medium were evaluated. The maximum sorption capacities of IL-treated shell residues (0.39-0.61 g/g) were about 1.5-fold to those of untreated shell residues (0.32-0.42 g/g), respectively. The effects of main environmental factors (temperature and pH) on oil removal were also studied. Kinetic models were successfully established for analyzing the oil sorption process. In addition, it was found that the IL-treated shell residues could be reused for several times. The results indicated that IL-treated yellow horn shell residues could be developed as an ideal biosorbent for oil removal from water. (C) 2012 Elsevier Ltd. All rights reserved.