Electro-irradiated technologies for clopyralid removal from soil washing effluents

Abstract

In this work, electrolysis and electro-irradiated technologies, i.e. sonoelectrolysis, photoelectrolysis and photosonoelectrolysis have been evaluated in order to improve the biodegradability of soil washing effluents polluted with the herbicide clopyralid. Results obtained showed that simple electrolysis with carbon felt anodes improved the biodegradability of the effluent and that combination of electrolysis with irradiation technologies lead to very different operative results. Photoelectrolysis produced a synergistic effect in clopyralid removal and mineralization, while sonoelectrolysis and photosonoelectrolysis did not generate any positive effect, showing antagonisms. Regarding the biodegradability of the effluents, photoelectrolysis was the only technology which demonstrated a significant enhancement; nevertheless, it has associated an important energy consumption in comparison to simple electrolysis processes.