Thermodynamics and Instrumental Analysis of Congo Red Dye Adsorption onto Commercial Activated Carbon

A. Rajappa¹, K. Ramesh²,V. Nandhakumar^3*, Hema Ramesh¹_, S. Sivakumar¹ and S. Savithri^1 
1Department of chemistry, Sri Manakula Vinayagar Engineering College, Puducherry, India.
²Department of chemistry, Arasu Engineering college, Kumbakonam, India.
^3*Department of chemistry, A.V.V.M  Sri Pushpam college, Poondi, India.

Abstract
Adsorption of Congo Red (CR) from aqueous solution onto Commercial Activated Carbon (CAC) was investigated under various experimental conditions. Batch mode experiments were conducted. The characteristics of CAC were determined by SEM, XRD and FTIR. Equilibrium studies were carried out by varying the parameters such as contact time, initial dye concentration, pH of the solution and temperature. The initial concentration studies were carried out by taking 100,150,200,250 mg/L of solutions and effect of temperature study was carried out at 303,313,323 and 333K. Thermodynamic parameters for such as ΔH°, ΔS°, and ΔG° were determined using Van’t Hoff plots. Analysis of these values infered that the adsorption was endothermic, spontaneous, favorable. The FTIR and XRD studies confirmed that adsorption physisorption with partial chemisorption. The SEM image showed rough surface area with micropores and macropores. Adsorption capacity of the CAC for CR dye was good.
Keywords: Adsorption, Commercial Activated Carbon, Congo red, Thermodynamic parameters, SEM, XRD, FTIR Analysis.