Synthesis of Fe-doped Bi2O3 nanocatalyst and its sonophotocatalytic activity on synthetic dye and real textile wastewater.

Abstract

The catalysts such as Fe, Bi2O3, and Fe-doped Bi2O3 were synthesized for the sonophotocatalytic treatment of synthetic dye and real textile wastewater. The resultant catalysts were characterized for its size and uniform shape using x-ray diffractogram (XRD) and scanning electron microscopy (SEM) which signified the nanorod shape formed Bi2O3. The higher ultraviolet light absorbance capacity of the catalysts was also evident using diffuse reflectance spectroscopy (DRS). Initially, the effect of conventional parameters such as initial pH, gas bubbling (argon, oxygen, air and nitrogen) and oxidant addition (H2O2 and peroxymonosulfate) in the presence of sonolysis (22 and 37kHz frequency) and photolysis (UV-C light) on 10ppm Basic Brown 1 dye was studied. The results showed that highest decolorization of 62% was attained for 3g/L peroxymonosulfate under 37kHz frequency sonolysis treatment. Secondly, with the catalyst study, highest of 46% dye color removal was obtained with 4g/L Fe under 37kHz frequency sonolysis treatment. The sonophotocatalytic treatment of dye with Fe-doped Bi2O3 catalyst in combination with peroxymonosulfate showed highest color removal of 99%. Finally, the sonophotocatalytic treatment of real textile wastewater in the presence of 3g/L Fe-doped Bi2O3 and 6g/L peroxymonosulfate reduced the total organic carbon (TOC) and chemical oxygen demand (COD) level to 77 and 91%, respectively, in 180min. The reported treatment process was found to treat the synthetic dye and real textile wastewater effectively.