Title: Mechanism and kinetic model of the oxidative degradation of Rhodamine B dye in aqueous solution by ultrasound-assisted Fenton's process
Authors: Mahjabeen Akram; Sampa Chakrabarti
Addresses: Department of Chemical Engineering, University of Calcutta, 92, Acharya P.C. Road, Kolkata 700009, India ' Department of Chemical Engineering, University of Calcutta, 92, Acharya P.C. Road, Kolkata 700009, India
Abstract: A plausible mechanism for sono-Fenton reaction has been proposed and a kinetic model was developed with verification by experimental data. Degradation of Rhodamine B dye using sono-Fenton process has been investigated. Effects of initial pH, initial dye concentration, dosage of FeSO4, H2O2 and ultrasonic power density were studied. Optimum values were: pH = 3, H2O2 = 2.74 × 10-2 mol/dm3, FeSO4 = 3.60 × 10-4 mol/dm3. Maximum 99.57% decolourisation and 69.41% COD reduction were obtained in 30 minutes. Sono-Fenton process was more efficient than dark-Fenton or sonolysis under the same conditions. Decolourisation rate increased with increase in initial dye concentration up to 7.30 × 10-4 mol/dm3 after which it decreased. Similarly, the maximum decolourisation rate was obtained at 2.74 × 10-2 mol/dm3 of H2O2. Decolourisation increased with increasing FeSO4 dosage and ultrasonic power density. Initial rate was influenced by initial dye concentration, ultrasonic power density and the initial dosage of H2O2 and FeSO4.
Keywords: kinetics; mechanism; sono-Fenton's process; Rhodamine B dye; wastewater; ultrasonic cavitation; decolourisation; COD removal.
International Journal of Environment and Waste Management, 2022 Vol.29 No.1, pp.80 - 94
Received: 02 Sep 2019
Accepted: 22 Jan 2020
Published online: 28 Jan 2022 *