Powdered activated carbon adsorbent for eosin Y removal: modeling of adsorption isotherm data, thermodynamic and kinetic studies

Abstract

Abstract An investigation was conducted to examine the adsorption of eosin Y (EY) from aqueous solution using Powdered Activated Charcoal (PAC) obtained from Biochem Chemopharma (Quebec, Canada) with a surface area of 270 mg/g using the methylene blue method. The adsorption experiments showed that a contact time of 60 min resulted in a high removal efficiency of 98.25 % for EY at a concentration of 10 ppm. The study also offered insights into the effectiveness of different treatment processes and described the main physicochemical processes involved. Various parameters such as adsorbent dosage, contact time, substrate concentration, and pH were evaluated, and the data were analyzed using Freundlich, Langmuir, and Temkin isotherms. The study found that the pseudo-second-order kinetic model provided a better fit to the experimental data compared to the pseudo-first-order model. To optimize the process parameters and enhance overall efficiency, contour plots were employed in the experimental design, considering variables such as adsorbent dosage, contact time, and pH levels. These plots visually represented the relationship between the variables and the removal efficiency of EY, enabling the identification of optimal operating conditions. The investigation’s findings contribute valuable insights into the adsorption of EY using PAC and offer practical implications for improving the efficiency of EY removal in various applications. The use of contour plots in experimental design was highlighted as a crucial tool for refining adsorption process parameters.