Removal of Amoxicillin from Processing Wastewater by Ozonation and UV-Aided Ozonation: Kinetic and Economic Comparative Study

Abstract

This work presents an empirical and scaling-up study of the degradation and mineralization of amoxicillin (AMX) from expired pharmaceutical formulations by O3-based processes. A set of UV–ozone-based experiments was used to model the kinetics of AMX degradation, considering several chemical/photochemical mechanisms (hydrolysis, direct ozonation, radical reactions, and photolysis). Finally, the modeling data were used for scaling-up purposes, considering CAPEX and OPEX costs on the US Gulf Coast basis. In terms of experimental results, the amoxicillin (AMX) pharmaceutical effluent was successfully degraded by ozone technology at high pH values. The semi-batch ozonation process was effective after 60 min of treatment in all experimental conditions, producing degradation intermediates recalcitrant to O3 oxidative process. From the bench-scale kinetics, scaling-up simulations indicate that the gain provided by adding a UV unit does not compensate for the increase in capital and operational costs of adding irradiation equipment. It suggests ozonation at high pH as the best cost-effective approach to degrade AMX. The figures-of-merit electric energy consumption per order (EEO) corroborates the scaling-up simulations. EEO results indicate no-UV ozonation as the best option to degrade AMX at high pH values. The EEO of the present work showed a lower energy consumption system than previous papers from the literature.