The Role of Mediated Oxidation on the Electro-irradiated Treatment of Amoxicillin and Ampicillin Polluted Wastewater

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.

Electro-irradiated technologies for clopyralid removal from soil washing effluents

“…This means that these reactions may compete with organic oxidation and that active radicals are not available to oxidize the organic pollutants. In the literature, a similar antagonistic effect has been previously reported [41].…”

“…Vidales et al [42] observed an antagonism effect in the mineralization of caffeine applying conductive diamond by means of sono-photo-electrochemical oxidation technology. On the other hand, Silva et al [41] reported also an antagonism in the degradation of amoxicillin and ampicillin using a similar technology.…”

“…The highest efficiency showed in photoelectrolysis could be explained because of the formation of additional hypochlorite during electrolysis. The SWE contained NaCl, this chemical could be decomposed into chlorine radicals by means of UV irradiation (Equations (12-13)) [41].…”

Testing and scaling-up of a novel Ti/Ru0.7Ti0.3O2 mesh anode in a microfluidic flow-through reactor

“…In previous works, related to the oxidation of antibiotics and methylparaben, it was also observed this behavior during electrolysis and photoelectrolysis with diamond anodes, and it was explained in terms of unexpected more facile oxidation of short-chain carboxylic acids [35,38]. Conditions: pH: 3.4; current density: 30 mA cm -2 ; clopyralid0: 100 mg L -1 .…”

Special Issue: New Trends in Photo (Electro)catalysis: From Wastewater Treatment to Energy Production

“…Cathodic materials were also the focus of some papers in which WWTP were coupled with the electrical energy production in microbial fuel cells [7,8] The effectiveness of PEC processes has been assessed also in combined processes with sono-electrolysis for the degradation of drugs [9]: in that case boron-doped diamond electrodes were used, which are widely known in the electrocatalysis field.…”