The Bombay Technologist

Photo-Fenton Oxidation of Azo Dyes in Textile Wastewaters in the Presence of FE/AC and FE-TIO₂/AC Catalysts

Rohit Nagargoje

Department of Chemical Engineering, Institute of Chemical Technology, Mumbai

Suheyda Atalay

Department of Chemical Engineering, Ege University, Izmir

Gulin Aytimur Ersoz

Department of Chemical Engineering, Ege University, Izmir

Burcu Palas

Department of Chemical Engineering, Ege University, Izmir

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Abstract

Azo dyes are the most common type of the synthetic dyes, especially used in textile industry and they are seriously hazardous for the environment because of their resistance to biological and chemical degradation. In this study, removal of the azo dye, Procion Red MX-5B by using Photo-Fenton oxidation in presence of Fe/Activated Carbon and Fe-TiO₂/Activated Carbon catalysts was investigated and the catalytic performances of the catalysts were compared. The activated carbon, which was used as catalyst support, was prepared from walnut shells by using ZnCl₂ as chemical activation agent. As well as the comparison of the catalytic performances of the catalysts, the optimum reaction conditions were determined by varying the initial hydrogen peroxide concentration, catalyst loading, pH, and the initial dye concentration in presence of both the catalysts. According to the experimental results, the highest removal efficiencies were obtained in presence of Fe/AC catalyst. The optimum conditions were determined as 2 mM of initial hydrogen peroxide concentration, 0.25 g/L of catalyst loading and pH 3 when the initial dye concentration was 100 mg/L in presence of Fe/AC catalyst and 4 mM of initial hydrogen peroxide concentration, 0.25 g/L of catalyst loading and pH 4 in presence of Fe-TiO₂/AC catalyst. The decolorization and degradation efficiencies were evaluated as 97% and 55% in presence of Fe/AC catalyst and 87.5% and 20.2% at the optimum conditions.