Electrochemical Removal of Clavulanic Acid from Aqueous Matrices Using BDD Anode

In this study, the application of the boron-doped diamond (BDD) electrode for electrochemical removal of clavulanic acid was investigated. The studied pharmaceutical is one of the most commonly prescribed β-lactamase inhibitors, which raises concerns about its impact on the spread of antibiotic resistance, as well as environmental toxicity. Preliminary experiments conducted in buffered solutions showed that neutral pH ensures substantially higher degradation rates than basic and acidic conditions. Further studies featuring standardized humic substances revealed that the presence of dissolved organic matter can even improve the process’s performance, resulting in over 99% degradation achieved within 30 min of the electrooxidation experiment. Two detected intermediates were identified as the products of a β-lactam ring cleavage, which supposedly led to the loss of enzyme inhibiting properties. Total organic carbon (TOC) analysis (namely the non-purgeable carbon—NPOC—assay) showed that the time necessary to fully mineralize clavulanic acid is significantly longer than to degrade it. Nevertheless, BDD electrodes can be successfully applied for the removal of the studied compound from aquatic environments, which confirms their suitability as a part of water treatment systems.