Ecotoxicological assessment and electrochemical remediation of doxorubicin

Abstract

Doxorubicin (DOX) is an anthracycline widely used in treatments of several cancers, so it has found in hospital effluents with a significant concentration (above 1 μg L −1 ). Electrochemical remediation is an alternative to promote its degradation. The aim of this work was to evaluate the ability of nanostructured graphite electrodes with metallic oxides to degrade DOX by electro-oxidation (EO). Graphite, TiO 2 @graphite and AuO-TiO 2 @graphite electrodes were used in medium with tap water or 10 mmol L −1 NaCl. DOX treatments at concentrations of 1.25–5 mg L −1 were carried out in a voltage source with 1.5–5 V. The cathode used was the platinum electrode. The treatment of DOX 1.25 mg L −1 with 10 mmol L −1 NaCl electrolyte using the AuO-TiO 2 @graphite electrode at 5 V and 1 mA was the best methodology to promote its degradation. Also, the modified electrode was efficient to DOX degradation after 17 cycles of reuse. An energy expenditure of 1.11 and 0.2 kWh m −3 were obtained for 3 and 50 mL of treatment, respectively. Fish embryo acute toxicity test with zebrafish (Danio rerio) were performed before and after treatment by EO using NaCl. This treatment caused no effect on embryo-larval development, however it induced significant damage in the DNA of the zebrafish larvae after 96 h of exposure, which emphasizes the importance of a depth ecotoxicological evaluation during the development of EO methodologies.