Adsorption behavior of Crys tal Violet dye in aqueous solution using Co+2 hectorite composite as adsorbent surface

This s tudy focused on the adsorption behavior of the cationic Crys tal Violet (CV) dye from aqueous solutions using a Co+2‒hectorite composite as an adsorbent surface. The initial and equilibrium CV dye concentrations were determined using a UV-Vis spectrophotometer. The results were discussed and presented for the impacts of pH, primary CV dye concentration, composite dosage, and temperature. The optimum conditions were found for eliminating Crys tal Violet dye from the aqueous solution at a pH 4, ideal temperature 293 K, and 0.5 g L-1 of composite dose. The pseudo-second-order kinetic, intraparticle diffusion analyzed the tes ts’ data and film diffusion models. Each model’s defining features have been identified, and these models were in good agreement and in charge of regulating the adsorption reaction. The adsorption operation was also thermodynamically examined to determine thermodynamic variables such as Gibbs free energy (ΔGo), entropy (ΔSo), activation energy (Ea), and enthalpy (ΔHo). The negative value of Gibbs free energy (ΔGo) and enthalpy (ΔHo) indicated that the adsorption process was a spontaneous and exothermic reaction. While the activation energy (Ea) data which fell within the normal range for physisorption, was discovered to be 22.434 kJ mol-1. This result proved that physical adsorption occurs between the CV dye and the adsorbent surface (Co+2‒hectorite composite).