Biosorption of Remazol Orange Rr From Aqueous Solution: Kinetic, Equilibrium and Thermodynamic Studies

Abstract

Remazol Orange RR ( RORR) is one of the most frequently used textile dye which causes environmental pollution. In the present study, parameters affecting the RORR biosorption with dead Saccharomyces cerevisiae yeast were investigated. The maximum %RORR removal was found to be 84.9% at 2 g/L biosorbent dosage, 200 mg/L initial dye concentration, pH 3.0, and 25 degrees C. RORR biosorption with S. cerevisiae was expalined by pseudo-second-order kinetics model and Langmuir adsorption isotherm with correlation coefficient ( R-2) of 0.99 and 0.87, respectively. The enthalpy change (Delta H), entropy change (Delta S) and activation energy ( E-a) were determined as 35.9 kJ/mol, 88.1 kJ/mol K and 3.36 kJ/mol, respectively. In addition, Gibbs free energy change was calculated as -10.04, -8.03 and -8.33 kJ/mol for 298, 308 and 318 K, respectively. It is concluded that the biosorption of RORR by S. cerevisiae occurs mainly by physical adsorption through a spontaneous process. The high dye removal and biosorbent capacity indicated that S. cerevisiae is a promising biosorbent for dye removal.