Sonophotocatalytic treatment of methyl orange dye and real textile effluent using synthesised nano‐zinc oxide

Abstract

In this work, experiments were carried out by combining the sonication technique with the photocatalytic technique (ultraviolet light source) for the degradation of methyl orange dye and real textile effluent. Studies were performed with variation in parameters such as oxidant (sodium persulfate), commercially available zinc oxide, methyl orange concentration, and sonochemically synthesised zinc oxide. Fourier transform infrared spectroscopy, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, and X‐ray diffraction analysis of synthesised zinc oxide showed that the particle size was in the nano range. Near‐complete colour removal by sonophotocatalytic treatment was observed for a concentration of 10 mg l−1 of methyl orange with 1 g l−1 of synthesised zinc oxide and 1500 mg l−1 of sodium persulfate. For 100 mg l−1 of methyl orange, the colour removal was 77% for 1 g l−1 commercially available zinc oxide and 84% for 1 g l−1 synthesised zinc oxide respectively, with 1500 mg l−1 sodium persulfate. Similar experimental conditions were applied for the sonophotocatalytic treatment of real textile effluent with different dilutions (1:100, 1:10, and 1:1) and raw effluent. For real textile effluent, sonophotocatalytic treatment was found to be highly effective both in colour and chemical oxygen demand removal. The chemical oxygen demand removal was 88, 65, 63, and 41% for 1:100, 1:10, and 1:1 dilutions and raw effluent respectively.