Studying adsorption of chalcone by using tea leaf powder and activated charcoal

Abstract

This study aimed to evaluate the adsorption efficiency of tea residue powder as a natural adsorbent and activated charcoal as a synthetic adsorbent for the removal of the chalcone compound  ((E)-1-(benzofuran-2-yl)-3-(4-bromo phenyl)pro-2-en-1-one), which was prepared from the reaction of 4-bromo benzaldehyde with 2-acetyl benzofuran). The effect of various factors on adsorption efficiency such as (adsorbent amount, contact time, adsorbate concentration, pH, and  temperature) was studied. The highest removal percentage (79.01%) was achieved when using tea leaf powder at an equilibrium time of 30 minutes. When using activated charcoal, the highest removal percentage (90.87%) was achieved at an equilibrium time of 30 minutes. Four isotherm models were applied to describe the adsorption system; all showed linear relationships with good correlation coefficients. The Freundlich model was found to be the most suitable due to its highest correlation coefficient for both adsorbents used in this study. The study also included calculating thermodynamic function values which indicated that the adsorption process using both types of adsorbents is spontaneous based on ΔG values and exothermic based on calculated ΔH values. In addition, ΔS values indicated that the adsorbate tends to be more organized on the surfaces of the used adsorbents than in solution.