Sonochemical synthesis of Ce-TiO2 nanocatalyst and subsequent application for treatment of real textile industry effluent

Treatment of real textile industry effluent using photocatalysis, sonocatalysis, sonophotocatalysis and H2O2 assisted sonophotocatalysis have been studied based on the use of Ce-TiO2 nanocatalyst synthesized using sonochemical co-precipitation method. Characterization studies of the obtained catalyst revealed crystallite size as 1.44 nm with particles having spherical morphology. A shift of the absorption edge to the visible light range was also observed in UV-Vis diffuse reflectance spectra (UV-DRS) analysis. The effects of different operational parameters viz catalyst dose (0.5 g/L-2 g/L), temperature (30 degrees C-55 degrees C) and pH (3-12) on the COD reduction were studied. The reduction in the COD was higher at lower pH and the optimum temperature established was 45 degrees C. It was also elucidated that the required catalyst dose was lesser in combined sonophotocatalysis when compared with individual photocatalysis and sonocatalysis. Combination of processes and addition of oxidants increased the COD reduction with the sonophotocatalytic oxidation combined with H2O2 treatment showing the best results for COD reduction (84.75%). The highest reduction in COD for photocatalysis was only 45.09% and for sonocatalysis, it was marginally higher at 58.62%. The highest reduction in COD achieved by sonophotocatalysis was 64.41%. Toxicity tests coupled with Liquid Chromatography Mass Spectrometry (LC-MS) analysis revealed that there were no additional toxic intermediates added to the system during the treatment. Kinetic study allowed establishing that generalized kinetic model fits the experimental results well. Overall, the combined advanced oxidation processes showed better results than the individual processes with higher COD reduction and lower requirement of the catalyst.

Automated summary

The treatment of real textile industry effluent using combined advanced oxidation processes, such as photocatalysis, sonocatalysis, sonophotocatalysis, and H2O2 assisted sonophotocatalysis, with Ce-TiO2 nanocatalyst synthesized using a sonochemical co-precipitation method, was studied. The obtained catalyst showed a crystallite size of 1.44 nm and spherical morphology. UV-Vis diffuse reflectance spectra (UV-DRS) analysis revealed a shift of the absorption edge to the visible light range. The effects of different operational parameters, including catalyst dose, temperature, and pH, on COD reduction were investigated. The combined sonophotocatalysis with H2O2 treatment showed the best COD reduction (84.75%), with lower catalyst requirement compared to individual photocatalysis and sonocatalysis.