Photo-degradation of acid red 44 using Al and Fe modified silicates.

Al and Fe modified silicates were synthesized using the hydrothermal method. The obtained materials were calcined at different temperatures (250, 500 and 750 degrees C) and characterized using XRD, FTIR, UV and SEM spectroscopy. The obtained materials were applied for the photo-decolorization of acid red 44 as a member of azo dye family, in aqueous medium using UV irradiation (lambda=254 nm) under different experimental conditions. The effect of calcination temperature, catalyst concentration and pH on the decolorization of acid red 44 dye were investigated. The decolorization of acid red 44 dye and the decreasing in concentration of the formed intermediates have been followed using UV-vis spectrophotometry and high performance liquid chromatography (HPLC). Results showed that the addition of Al and Fe-silicate to the dye solution as well as pH change greatly enhanced the rate of degradation. The decolorization followed the pseudo first order kinetics model and a significant mineralization of AR44 was observed.