CATALYTIC DYE DECOLORIZATION OF TEXTILE WASTEWATER

Abstract

Azo dyes are generally used as colorants in printing, textile and paper industries. Discharge of wastewater from these industries contains significant amount of these azo dyes making the water polluted and unsafe to be used. These azo dyes should be degraded before drainage in order to decrease the contamination in the wastewater. The first step in the degradation of azo dyes is the discoloration process, which not only removes the color from the water but also turns the dyes into less harmful products. The most commonly used discoloration process is a catalysis process that uses a catalyst or its composites to decolorize the dye and has good efficacy in removing dyes. In this study, dye decolorization has been performed using catalysis technique. Depolymerization of waste PET bottles has been done to obtain Benzene-1, 4-dicarboxylic acid to synthesize Cerium Benzene 1.4-dicarboxylate catalyst. Other than this, Ni/CeO2, Ni/Nb2O5 and Ni/ZrO2 catalysts were synthesized and prepared through wet impregnation. Also our last catalyst Palladium-Activated carbon was obtained commercially. Then all these catalysts were analyzed using several analytical techniques like X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and UV-visible spectroscopy. As synthesized catalysts were subjected to the reduction of methyl orange an azo dye being used in textile industry at large scale. Results have shown that cerium based catalyst has amazing catalytic efficiency for decolorization of methyl orange. But when compared it with Ni/CeO2, Ni/Nb2O5, Ni/ZrO2 and palladium-activated catalyst for methyl orange reduction, degradation efficiency has further increased. The kinetic data has also been generated for dye degradation process.