Mathematical modeling of manganese adsorption onto bone char in a continuous fixed bed column incorporating backmixing and shriking core approaches

Abstract

-The present study investigated the dynamics of manganese adsorption onto bone char in a continuous fixed bed column using a mathematical model that incorporates: (i) the backmixing model to describe the fluid flow through the bed and (ii) the shrinking core model to describe the kinetic and mass transfer phenomena within spherical adsorbent particles. The proposed model consists of an ordinary differential equation system. Hydrodynamic, kinetic and diffusive parameters were determined by fitting the mathematical model to the experimental data obtained by Sicupira et al. (2015). For the operating conditions evaluated in this study, the intraparticle diffusion represented the controlling step of the adsorption process (Bi m > 3.8). The increase in the feed rate of the column (3.0-7.5 mL min -1 ) and the decrease in the height of the bed (8-16 cm) resulted in a decrease in the time required for the saturation of the column bed. The model is flexible for a variety of flow conditions and adequately reproduced the behavior of the manganese adsorption process in the fixed bed column operation (R²> 0.99) with an average percentage error less than15%.

Investigation of the transport characteristics of Pb(II) in sand-bone char columns

“…Therefore, when the flow rate was low, both the breakthrough and termination times increased, and the breakthrough curve tended to be flat, which is consistent with the adsorption characteristics of Mn(II) on bone char. 49 Furthermore, the Dose-Response model fit the breakthrough curve of the experimental data well. As shown in Tables 8 and 9 , the length of the adsorption mass transfer zone and the adsorption capacity of the adsorbent decreased as the flow rate increased.…”