Ultrasound-assisted Fenton process using siderite nanoparticles prepared via planetary ball milling for removal of reactive yellow 81 in aqueous phase

Nano-sized siderite was used as catalyst for the heterogeneous Fenton process combined with ultrasonic irradiation to degrade reactive yellow 81 (RY-81) in the aqueous phase. As the most efficient process, nano-sized siderite prepared via ball milling was chosen to carry out the experiments. 6 h milled siderite at initial pH of 3.0 led to the highest removal efficiency of 92.09% within the reaction time of 30 min. At a short reaction time of 20 min, increasing siderite nanoparticles dosage from 0.3 to 0.75 g/L resulted in increasing removal efficiency from 49.82 to 79.86%, respectively, while further increase in the dosage caused a substantial decrease in the efficiency. In the case of the effect of solute concentration, increasing the dye up to 400 mg/L led to a significant decrease in the removal efficiency (65.77%). The presence of 0.01 M Na₂CO₃ and C₂H₅OH significantly diminished the decolorization efficiency of RY-81 (<10%) with initial concentration of 100 mg/L. The intermediates produced during the treatment process were also identified using GC–MS analysis. This research suggested that ball milled siderite is a potential catalyst for the efficient decolorization of textile effluents via ultrasound-assisted Fenton process.