Mathematical modeling of breakthrough curves for 8-hydroxyquinoline removal from fundamental equilibrium and adsorption rate studies
Samuel Aguirre-Contreras, Roberto Leyva‐Ramos, Raúl Ocampo‐Pérez, Carlos G. Aguilar-Madera, J.V. Flores-Cano, Nahúm Andrés Medellín-Castillo
Abstract
The mathematical modeling of the dynamic adsorption of 8-Hydroxyquinoline on activated carbon (AC) in batch and fixed-bed adsorbers is outlined in this study. The model is centered on the mass transport phenomena occurring in the solution and inside the adsorbent and considers the axial dispersion , convective transport, intraparticle diffusion mechanisms , and adsorption on the active site. Moreover, this work proposes a methodology to solve the model based on basic studies of adsorption equilibrium and rate; therefore, the prediction of the breakthrough curves by fitting the mass transport parameters is not considered, which is a significant advance in the design of fixed-bed columns. The equilibrium results demonstrated that 8-HQ adsorbs on AC by dispersive π-π and hydrophobic interactions with a mass 8-HQ adsorbed of 454 mg g −1 . The kinetic study revealed that the time to achieve equilibrium diminished by up to 200 min upon establishing a turbulent stirring regime. In addition, it was found that intraparticle transport is governed by surface diffusion . Finally, using the information obtained in the batch regime, it was possible to interpret and predict the packed bed behavior in a broad range of operational conditions with an error of 10.6 % in the prediction of the breakthrough point.