Correlation Study of Batch and Fixed Bed Adsorption Procedures Based on the Binding Capacities for Water Pollutants

Abstract

In theoretical studies or practical applications, all adsorption separations, including water pollutant treatment, can be realized by batch or fixed bed processes. However, much uncertainty still exists about the correlation between the adsorption uptake of the two processes of the same adsorption system. To address this issue, batch and fixed bed processes are designed using adsorbent/adsorbate pairs, such as activated carbon, which is commonly used in water treatment. The adsorption capacities of the two processes are obtained under the same or constant parameters, including adsorbent mass, adsorbate solution volume, adsorption time, and temperature. The results demonstrated that there is a significant correlation between the adsorption uptake of the two processes. The correlation can be divided into two distinct categories: r is either directly proportional or kept constant to the adsorbate concentration increase and it is almost less than one in all cases. The relative error between the predicted value and the experimental value was 5.7%. The findings of this study have a significant importance and can be a good reference for further exploration of the mathematical model of the correlation between the adsorption capacities of the two processes. Moreover, the model will provide a powerful tool for the comparison and selection of the appropriate process and in the extraction of adsorption parameters of one process from that of another.