Biosorption of CD 2 + and PB 2 + with Cocoa Bark: Experimentation, Mathematical Modeling and Simulation Numerical

Abstract

Abstract Cocoa shell is a potential adsorbent for the removal of pollutants from wastewater. The goal of this study was to compare, model and simulate the removal of Pb 2 + and Cd 2 + in a fixed bed column using cocoa shell. The experimental studies were carried out in a laboratory burette with a bed height of 10.5 cm, a volumetric flow of 2 mL/min, and a metal concentration of 10 mg/L. The empirical models of Thomas, Dose-Response, and Wang were used to study the dynamic behavior of biosorption, in addition a mathematical model based on a differential mass balance of the column was proposed to study the effect of the axial dispersion phenomenon. The results indicated that the active sites of cocoa shell have a higher affinity for the Pb 2 + cation, with breakthrough and saturation times higher than Cd 2 + . The Dose-Response model was the one that presented the best fit with experimental data, confirming that the adsorption capacity of the cocoa shell is superior with Pb 2 + . The axial dispersion phenomenon is relevant and should not be neglected in the approach of laboratory scale models.

Keywords

• cocoa shell, biosorption, heavy metals, numerical simulation