Improved degradation of oseltamivir phosphate, an antiviral drug, through hydrodynamic cavitation based hybrid advanced oxidation processes: An insight into geometrical parameter optimization

Abstract

The study focused on using hydrodynamic cavitation (HC) to degrade Oseltamivir Phosphate (OP), a pharmaceutical compound found in sewage and surface water. Eight cavitating devices, including a circular venturi and seven orifice plates with different flow areas and perimeters, were evaluated. The influence of operating factors, including solution pH, inlet pressure, and cavitation number on OP degradation was studied and identifying the optimum conditions for this process. Oxidizing agents like H2O2, Fenton's reagent, and ozone were combined with HC to enhance OP degradation. Using HC with H2O2 at a 1:40 OP to H2O2 molar ratio led to 99.51 % degradation within 90 min, while HC with ozone at a 3 g/h feed rate achieved 95.43 % degradation within 30 min. A 1:3 molar ratio of FeSO4·7H2O to H2O2 with HC resulted in 86.87 % degradation. The highest mineralization rate, 68.3 × 10−3 min−1, was attained using HC and ozone. The per pass removal factor was used to assess the degradation efficiency of the cavitating devices. The study conducted a comparative analysis of the cavitational yield and treatment cost, with the HC+O3 method yielding the highest cavitational yield of 2.67 × 10−4 mg/J and lowest treatment cost at 0.000221US$/(L.mg). The degradation pathway of HC+O3 has also been established.