KINETICS OF DECOLORIZATION OF ALIZARIN RED S IN AQUEOUS MEDIA BY FENTON-LIKE MECHANISM

Abstract

The decolorization kinetics of Alizarin Red S (ARS) in aqueous solution was studied using Fenton like reaction in dark environment. The effects of dye, iron(III) ions and hydrogen peroxide concentrations were investigated. The reaction was first order in ARS, H2O2 and zero order in iron(III) chloride. Increasing the hydrogen peroxide concentration (2-8 x10-3 mol dm-3) increases the rate constant from 1.05x10-3 to 3.2 x 10-3 s-1 and excess of hydrogen peroxide shows no effect on the rate constant. Iron(III) ions concentration shows soft retardation effect on the degradation rate of ARS. Increasing the initial ARS concentration from 1 to 4x 10-4 mol dm-3 decreases the decolorization from 85 % to 55 % within 15 minutes. Increasing temperature in the range of 298-313 K increases the rate of degradation and no optimal value detected. In addition, the influence of inorganic additives such, carbonate, nitrate and chloride on the efficiency of dye removal were examind