Electrochemical oxidation of psychoactive compounds using RuO₂/IrO₂ electrodes: impacts on neuronal activity and water matrix influence

BACKGROUND This study focuses on utilizing the electrochemical oxidation (EO) process to eliminate psychoactive substances and aims to assess the impact of EO‐treated water on the neuronal activity of rat hippocampus (specifically the CA3 region). The effectiveness of the ruthenium–iridium (Ru/Ir) EO process in degrading a mixture of carbamazepine and four benzodiazepines (alprazolam, clonazepam, diazepam and lorazepam) was evaluated in ultrapure (UP) water under various pH levels (ranging from 3 to 10), current densities (30–50 A m −2 ) and electrolyte concentrations (0.5 and 1.0 g L −1 NaCl). Ru/Ir were used as anode materials, with all pharmaceutical compounds initially present at a concentration of 100 μg L −1 in the mixture. Experiments were also conducted with surface water (SW) and municipal wastewater (MWW). RESULTS The optimal conditions, achieved at a current density of 50 A m −2 , pH 7 and 1.0 g NaCl L −1 , led to complete degradation of the compounds in 5 min. Higher removal efficiency were observed in UP water compared to real matrices, indicating greater competition for radicals in complex compositions. When using MWW, residual pharmaceuticals were detected even after 120 min of reaction. Neurotoxicity studies revealed varying impacts on reactive oxygen species production, with SW‐treated solutions showing reversible effects and MWW‐treated solutions displaying irreversible increases, highlighting the significance of Ru/Ir electrodes in EO processes. CONCLUSION Overall, this study demonstrates the efficacy of EO using Ru/Ir electrodes for removing psychoactive substances from water sources. Thus, assessments of neurotoxicity can be incorporated into evaluations of treatment process effectiveness, serving as a complement to physicochemical analyses.