Sorption of Ethylbenzene, Toluene and Xylene onto Crumb Rubber from Aqueous Solutions

Samples of waste tires crumb rubber mesh 14-20, produced by REMA Inc., were contacted with 30ppm aqueous solutions of ethylbenzene (E), toluene (T) and xylene (X) to evaluate the corresponding sorption capability. The concentration of the sorbent varied from 0.1 to 10 g crumb rubber/L. Solution aliquots were withdrawn at different times and analyzed by GC-MS to monitor the progress of the sorption process. Obtained results confirmed the capability of crumb rubber to remove ETX compounds from aqueous solutions. This removal efficiency was dependent on solution pH and crumb rubber concentration. The ethylbenzene concentration dropped from 30 ppm down to 1.4 ppm in the first 30 minutes of contact when 10 g/L of crumb rubber were used. The maximum removal of xylene, ethylbenzene and toluene were 99, 95 and 77%, respectively, at pH 6. The corresponding uptake capacities were 55, 48 and 24 mg/g crumb rubber. The sorption efficiency of crumb rubber was xylene > ethylbenzene > toluene.