Gold nanoparticle loaded activated carbon as novel adsorbent for the removal of Congo red

Abstract

The present investigation assesses the applicability efficiency and performance of gold nano particle loaded activated carbon (Au-NP-AC) adsorbent for remove the Congo red (CR) from wastewater. The adsorption characteristics and dye removal efficiency of adsorbent have been determined by investigating the influence of variables including pH, contact time, concentration of the dye, amount of adsorbent and temperature. The graphical correlation of various adsorption isotherm models like Langmuir, Freundlich and Tempkin have been used to evaluate the ongoing adsorption. Calculation of various thermodynamic parameters such as, Gibb's free energy, entropy and enthalpy of the on-going adsorption process indicate feasibility and endothermic nature of CR adsorption onto Au-NPAC. The kinetic studies suggest that the process follows pseudo second order kinetics and involvement of particle diffusion mechanism.