The Kinetic and Thermodynamic Study for Decolorization of Congo red from Aqueous Solution Using Electrocoagulation Process

Abstract

The removal of color from synthetic wastewater containing Congo red was experimentally investigated using electrocoagulation process. The effects of operational parameters such as current density, electrolysis time, electrolyte concentration, electrode distance, initial dye concentration, initial pH and temperature on color removal efficiency were investigated in this study. The tentative results showed that Congo red in the aqueous phase was removed effectively by electrocagulation procedure. Optimum operating range for each of these operating variables was experimentally determined. Under the conditions of an initial dye concentration of 50mg/l, electrolysis time 5min, initial pH 7.5, current density 150A/ m2 , sodium chloride concentration 10g/l, interelectrode distance 0.5 cm, the color removal efficiency reached 98% when electrical energy consumption in this conditions for the decolorization of the dye solution containing Congo red was 0.46 KWh/m3 . Outcomes showed that the first-order rate equation could be described correlation for the decolorization rate of Congo red. The thermodynamic parameters, such as ∆Ho , ∆So and ∆Go , were also determined and evaluated. Further the experimental data were tested with different adsorption isotherm model to describe the electrocoagulation process.