The experimental set-up was designed to study the adsorption phenomena for the removal of VOCs (i.e., toluene and xylene) on commercially available granular activated carbon. Breakthrough curves were then drawn for both toluene and xylene under varying operating conditions. A mathematical model was also developed to predict the time-dependent (unsteady state) concentration profiles of the adsorbing species (VOCs) on a solid adsorbent under isothermal conditions. The non-linear coupled partial differential equations were discretized by using orthogonal collocation technique and the resulting ordinary differential equations were solved by using Gear's method. The mathematical model was found to be robust and experimental and its predicted results were found to be in good agreement. Simulations were then carried out to predict the behavior of breakthrough curves for toluene and xylene on granular activated carbon under varying operating conditions such as flow rate, particle diameter, pore diffusivity, bed height, and inlet concentration. Further sensitivity analysis was done to find the most sensitive parameter with respect to breakthrough time. In addition the concentration of VOC in the pores of the adsorbent particle and in the bulk phase was determined with the help of a mathematical model, and the performance of granular activated carbon was found to be better in adsorbing xylene in comparison to toluene when breakthrough curves were drawn for the same input parameters.