Sonocatalytic decolorization of textile wastewater using synthesized γ-FeOOH nanoparticles.

γ-FeOOH nanoparticles were synthesized and applied for decolorization of a textile wastewater containing reactive orange 29 (RO29) by ultrasonic/γ-FeOOH/H2O2 process. X-ray diffraction, transmittance electron microscope, scanning electron microscope, and nitrogen adsorption/desorption analysis approved synthesis of γ-FeOOH nanoparticles with the average width of 60-70 nm. The catalyst dosage, H2O2 concentration, pH, and ultrasonic power had significant effect on catalytic performance of γ-FeOOH nanoparticles. γ-FeOOH nanoparticles can be effectively used as catalyst in successive US/γ-FeOOH/H2O2 processes without significant activity loss. Gas chromatography-mass spectrometry analysis was used to verify the main intermediates produced through the RO29 degradation. Mineralization of the textile wastewater during treatment process was determined by chemical oxygen demand analysis.