Iranian Research Organization for Science and Technology Advances in Environmental Technology 2476-6674 10 1 2024 01 01 Degradation of azo dyes using hydrodynamic cavitation and external oxidants 55 69 1362 10.22104/aet.2024.6092.1679 EN Manisha V Bagal Department of Chemical Engineering, Bharati Vidyapeeth College of Engineering, India Vinayak Rajan Department of Chemical Engineering, AISSMS College of Engineering, India Shubham Shinde Department of Chemical Engineering, AISSMS College of Engineering, India Barnali V Banerjee Department of Chemical Engineering, AISSMS College of Engineering, India Vitthal Gole Department of Chemical Engineering, Madan Mohan Malaviya University of Technology, India Ashish V Mohod Department of Chemical Engineering, AISSMS College of Engineering, India Journal Article 2023 07 19 Hydrodynamic cavitation (HC) with an orifice as the cavitating device was used to study the degradation of methyl orange dye. The operating parameters of the process, such as pH and inlet pressure, were optimized. The effect of hydroxyl radical promoters like Fenton oxidation and hydrogen peroxide (H₂O₂) on the extent of degradation was also investigated. It has been observed that acidic conditions (pH 2) favor the degradation of methyl orange. The combined effect of hydrodynamic cavitation with hydrogen peroxide was investigated at the solution’s natural pH and an optimized solution pH 2. Maximum degradation of 99.2% was observed at natural pH, whereas complete degradation of methyl orange dye was observed at pH 2 with 8 ml/L of hydrogen peroxide addition. The hybrid process of HC/Fenton and HC/H₂O₂ showed the highest efficiency for the degradation of methyl orange with a minimum energy requirement (0.11 kWh) and operational cost (USD $<strong> </strong>0.0062/L).   https://aet.irost.ir/article_1362_2d4fd60ed443ef678fb042aa83190f93.pdf