Studies on UV/NaOCl/TiO2/Sep photocatalysed degradation of Reactive Red 195

Abstract

The photocatalytic degradation of Reactive Red 195 (RR195) has been investigated in aqueous suspensions by using ultraviolet (UV), sodium hypochlorite (NaOCl) and TiO2/Sep nanoparticles together. To get the TiO2/Sep nanoparticle, the nanocrystalline TiO2 anatase phase on sepiolite was obtained using a sufficient thermal treatment by gradually increasing the temperature from 300, 400 and 500 degrees C for 3 h. Then, TiO2/Sep materials were characterized using different spectral and technical structural analyses with scanning electron microscopy (SEM) and X-ray diffraction (XRD). The influence of pH, catalyst amount, oxidant and initial dye concentration was investigated in all the experiments. Maximum colour and chemical oxygen demand (COD) removal were 99.9% and 78% respectively, at a dye concentration of 250 mg L-1. NaOCl dosage of 50.37 mM, 0.1 g L-1 weight of TiO2/Sep and pH of 5.45 in 3 h. In addition, the pseudo-first order model was applied and r(2) values were noted from 0.92 to 0.99. (C) 2009 Elsevier B.V. All rights reserved.