The Role of the Anode Material in Selective Penicillin G Oxidation in Urine

In this work, the removal of antibiotic penicillin G by electrolysis with boron doped diamond (BDD) and mixed metal oxide (MMO) anodes in urine media is evaluated. First, electrolysis in different water matrices (sulfate, chloride and urine) were carried out with diamond anodes to shed light on the contribution of mediated mechanisms. Results showed that penicillin G was completely removed by electrolysis for electric charges below 5 Ah dm(-3), regardless of the water matrix and the current density applied (10-100 mA cm(-2)). Then, the influence of the anode material was evaluated for the degradation of penicillin G in urine media. A complete removal of the antibiotic was attained, regardless of the tested anode material, although the BDD anode was found to be more efficient than MMO. Results also showed that, at the current charges in which the antibiotic is depleted, the removal of other organics was much lower and the formation of chlorates was negligible, especially operating at low current densities. Because of this selective oxidation of the pharmaceutical compound, electrolysis can be proposed to be used as a pre-treatment technology for later and cheaper biological treatment.