**Fernando L. Silva 1, Cristina Sáez 2,\*, Marcos R.V. Lanza 1, Pablo Cañizares <sup>2</sup> and Manuel A. Rodrigo <sup>2</sup>**


Received: 2 November 2018; Accepted: 18 December 2018; Published: 24 December 2018

**Abstract:** In this work, the electrolysis, photoelectrolysis and sonoelectrolysis with diamond electrodes of amoxicillin (AMX) and ampicillin (AMP) solutions were studied in the context of the search for technologies capable of removing antibiotics from liquid wastes. Single-irradiation processes (sonolysis and photolysis) were also evaluated for comparison. Results showed that AMX and AMP are completely degraded and mineralized by electrolysis in both chloride and sulfate media, although the efficiency is higher in the presence of chloride. The effect of the current density on mineralization efficiency is not relevant and this may be related to the role of mediated oxidation. Irradiation by ultraviolet light or ultrasound (US) waves does not produce a synergistic effect on the mineralization of AMX and AMP solutions. This indicates that the massive formation of radicals during the combined processes can favor their recombination to form stable and less reactive species.

**Keywords:** Anodic oxidation; diamond electrodes; UV irradiation; ultrasounds; amoxicillin; ampicillin
