Aplicação dos Processos Eletroquímicos Oxidativos Avançados (PEOAs) no tratamento de efluentes farmacêuticos utilizando ânodo de DDB

Abstract

In this study, the Anodic Oxidation processes with in situ hydrogen peroxide (OA-H2O2) and Electro-Fenton (EF) processes were used to decontaminate two synthetic effluents containing the drugs caffeine and metformin hydrochloride (MET). the first one of the compounds most consumed by the general population and the last used in the treatment of type II diabetes. The anode using was the DDB Boron Doped Diamond. The efficiency of the processes was evaluated by means of spectroscopy in UV-vis, COD, COT and HPLC. In order to optimize the processes, the influence of operational parameters was studied, such as concentration of the support electrolyte, concentration of drugs, density of applied current (15, 30 and 60 mAcm-2) and pH equal to 3.0 ± 0.2. According to the results obtained, a decrease of 92% and 53% in chemical oxygen demand (COD) was achieved for caffeine after 360 min of electrolysis for EF and OA-H2O2, respectively, with an initial caffeine concentration of 100 mgL-1, with a constant current density of 30mAcm-2 and 0.05 molL-1 of the Na2SO4 electrolyte. As for MET, it was possible to notice that the increase in the applied current density also favored its removal using both processes, with a reduction of Total Organic Carbon Observing from 71% for EF and 70% for OA-H2O2 (60 mAcm-1). In terms of concentration reduction, HPLC analyzes showed a 97% decrease in concentration for EF when compared to OA-H2O2 which achieved 85% removal.