Degradation of neomycin using hydrodynamic cavitation based hybrid techniques

• Published in: Chemical engineering and processing 2023-11, Vol.193, p.109543, Article 109543
• Main Authors: Gawande, Gayatri D., Pinjari, Dipak V., Chavan, Prakash V.
• Format: Article
• Language: English
• Subjects: Advanced oxidation processes; Antibiotics; Hydroxyl radicals; Kinetic analysis; Process intensification; Wastewater treatment
• ISSN: 0255-2701; 1873-3204
• DOI: 10.1016/j.cep.2023.109543

•Degradation of neomycin using hydrodynamic cavitation (HC) based hybrid techniques.•Optimization of operating parameters for HC and HC based hybrid techniques.•Pseudo first order kinetics to correlate the experimental degradation data.•Estimation of synergetic coefficient and energy efficiency of hybrid techniques.•HC in conjugation with Fenton reagents has shown maximum COD reduction of 88%. In the present work, degradation of neomycin was performed using hydrodynamic cavitation (HC) alone and its combination with supplementary oxidative agents like H2O2 and Fenton reagents. Initially, the effect of concentration of H2O2 and Fenton reagents was studied individually and corresponding values were optimized to obtain maximum degradation of neomycin. The maximum degradation was found to be 71.80% at an H2O2 concentration of 35.30 × 10−3 mol/L while the corresponding value was obtained as 80.40% using Fenton chemistry at Fe2+:H2O2 molar ratio of 0.15:1 in 60 min. Further, degradation of neomycin was studied using HC alone and eventually, operating parameters such as inlet pressure, cavitation number, and solution pH were optimized. The maximum degradation was found to be 54.50% at 5 bar inlet pressure and solution pH of 3 in 60 min. Following the optimization of HC parameters, the degradation of neomycin was carried out using the combination of HC with H2O2 and Fenton reagents. The intermediates formed during degradation of neomycin were analyzed by LC-MS technique and subsequently, probable degradation mechanism of neomycin was proposed. The maximum degradation was obtained as 80% and 88% for HC + H2O2 and HC + Fenton reagents, respectively in 25 min. The kinetics of degradation was studied and subsequently, the synergistic coefficients were estimated. The synergistic coefficients were estimated to be 2.03 and 2.38 for HC + H2O2 and HC + Fenton reagents, respectively. Electrical energy efficiency was estimated as 8.70 × 10−4 mg of neomycin degraded/J for the HC + Fenton reagent system. [Display omitted]