Adsorption and Thermodynamic Studies on the Removal of Congo Red Dye from Aqueous Solution by Alumina and Nano-alumina

Abstract

Removal of Congo red dye from aqueous solution by adsorption onto alumina and nano alumina was investigated using batch adsorption process. The adsorption was studied at different concentrations and at various temperatures. Experimental results indicated that adsorption of the dye unto nano alumina surface followed better defined pattern than that of alumina. Adsorption pattern of nano alumina at different temperatures revealed that the nano adsorbent is more sensitive to temperature than the classical alumina. Adsorption capacity obtained from experiment correlated strongly with theoretical adsorption capacity obtained from the Langmuir isotherms. However, from calculated standard free energies of adsorption, Langmuir separation factors and thermodynamic parameters, nano-alumina is a better adsorbent than alumina.