Dynamic Adsorption Model Fitting Studies of Typical VOCs Using Commercial Activated Carbon in a Fixed Bed

The adsorption behaviors of five typical volatile organic compounds (VOCs) onto one commercial activated carbon (CAC) in a fixed bed were investigated in this study. The selected CAC as a model adsorbent has a high surface area of 1099.74 m2 g−1. Moreover, five kinds of typical VOCs, including acetone, ethyl acetate, propyl acetate, butyl acetate, and isopropanol, were chosen as the target pollutants. The adsorption capacities of the above VOCs were 289.8, 389.4, 443.7, 467.4, and 474.3 mg g−1, respectively. The adsorption data were fitted by using two dynamic adsorption models (Boltzmann and Yoon-Nelson) and four kinetic models (pseudo-first-order, pseudo-second-order, Elovich and Banham adsorption rate equation). Compared to other models, the Boltzmann model and the Banham adsorption rate equation could well fit the data of the selected sorption periods. These observations indicated that the fixed bed has a small effect of the mass transfer resistance and a high utilization for the adsorbent. Meanwhile, the Banham adsorption rate equation also could well predict the real condition and the maximum adsorption capacity of the adsorbent. Therefore, the present study clarified the adsorption dynamic behaviors of the selected VOCs onto the CAC in a fixed bed. We believe that the finding of this work is helpful to optimize the design of dynamic adsorption system for the removal of VOCs.