Adsorptive Performance of Polypyrrole-Based KOH-Activated Carbon for the Cationic Dye Crystal Violet: Kinetic and Equilibrium Studies
Abdulaziz Alghamdi, Abdel-Basit Al-Odayni, Naaser A. Y. Abduh, Safiah A. Alramadhan, Mashael T. Aljboar, Waseem Sharaf Saeed
Abstract
The aim of this work was to investigate the adsorptive performance of the polypyrrole-based KOH-activated carbon (PACK) in the removal of the basic dye crystal violet (CV) using a batch adsorption system. The equilibrium data, obtained at different initial CV concentrations ([Formula: see text]) and temperatures (25–45°C), were interpreted using the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherms, with the Langmuir model providing a better fit ([Formula: see text]) and a maximum adsorption capacity of 497.51 mg/g at 45°C. Under the examined conditions, the values of the thermodynamic parameters free energy, enthalpy, and entropy indicate a spontaneous, endothermic, and physisorption adsorption process. The kinetic data of the adsorption process were very well described by a pseudo-second-order model ([Formula: see text]). However, surface diffusion seems to be the main rate-controlling step. Thus, we concluded that PACK shows commercial potential for the removal of cationic dyes such as CV from industrial effluent.