Characterization of adsorption uptake curves for both intraparticle diffusion and liquid film mass transfer controlling systems

Typical parameters influencing AUC include liquid film mass transfer coefficient (kF), effective intraparticle diffusivity (DS), influent concentration (c0) and equilibrium parameters (such as Freundlich isotherm constants k and 1/n). These parameters were investigated in this research and the simulated results indicated that the ratio of kF/DS and Freundlich constant 1/n had impact on AUC. Biot number (Bi) was used to replace the ratio of kF/DS in this study. Bi represents the ratio of the rate of transport across the liquid layer to the rate of intraparticle diffusion. Furthermore, Bi is much more significant than that of 1/n for AUC. Therefore, AUC can be characterized by Bi. In addition, the obtained Bi could be used to determine DS and kF simultaneously. Both parameters (DS and kF) are important for designing and operating fixed bed reactors.