Experimental study of the adsorption of eosin yellow dye on the surface of coal derived from walnut shells and a theoretical study through density functional theory

Abstract

Since water pollution constitutes a large part of the pollutants spread on the surface of the earth, pollution is unfortunately the most deadly silent weapon in the world today, especially in light of technological progress. Many efforts have been made to get rid of these pollutants. This study aimed to purify water from pollutants and determine the ideal conditions to improve the adsorption process of eosin yellow dye on the surface of activated carbon derived from walnut shells. Several studies have found that different acidity functions, contact times (512 min for dye), and temperatures (ranging from 298 to 328 K) all played an important role. The adsorption curves were also studied as they apply to Temkin and studying the kinetics of the reaction, and the second-order reaction was reached through the R² value, which was the highest theoretical value by studying the dye in the optimized geometries in the basic case B3LYP and the basis sets 6-311G using density functional theory (DFT). The theoretical features discovered through density functional theory (DFT) simulations such as the HOMO-LUMO value can be used to identify the active sites.  The aim of the theoretical study was to know the energy properties of the dye.