Chloride-mediated electrochemical degradation of the venlafaxine antidepressant

The presence of venlafaxine, one of the popular antidepressants, in environmental aquatic media has become a rising issue and potential threat to global ecology and human health. However, advanced technologies for efficient venlafaxine degradation remain underdeveloped. Herein, we propose to use chloride-mediated electrochemical degradation to efficiently remove venlafaxine in aqueous media. The degradation rate of venlafaxine can be significantly increased when Cl⁻ is added to the conventional electrochemical degradation process. It is found the Cl⁻ can convert to Cl^⋅, which selectively attacks benzene ring and accelerates its opening, thus leading to the improved degradation and mineralization performance of venlafaxine. Based on the analysis of reactive species and degradation intermediates, the degradation pathways with and without Cl⁻ were proposed. Toxicity test demonstrates that the toxic oxidation products formed during venlafaxine degradation could be completely mineralized in the chloride-mediated electrochemical degradation process. This work demonstrates the chloride-mediated advanced oxidation technology may be a promising way to degrade venlafaxine, which may also apply to other emerging antidepressants contained benzene ring, thus paving a new route for the removal of organic pollutants.