Résumé
The growing prevalence of micropollutants in water resources has emerged as a critical environmental and public health challenge. Micropollutants, often originating from pharmaceuticals, personal care products, pesticides, and industrial discharges, are typically present at trace concentrations (parts per billion or million) but pose disproportionate ecological and toxicological risks. Among emerging water treatment strategies, electrooxidation with boron-doped diamond (BDD) electrodes has gained attention as a promising approach to remove these persistent contaminants and meet stricter water quality standards, such as those established by the European Water Framework Directive.This study investigates the electrooxidative removal of carbamazepine, diuron, and perfluorooctane sulfonate (PFOS) from synthetic wastewater effluents containing organic matter concentrations representative of membrane filtration outputs, simulating advanced-stage treatment conditions relevant to municipal and industrial polishing processes. Emphasis was placed on the quantification of trace-level micropollutants and some of their degradation products using a validated solid-phase extraction method coupled with liquid chromatography-mass spectrometry, enabling reliable analysis in complex water matrices.Electrooxidation experiments were conducted using a laboratory-scale, single-compartment electrochemical cell fitted with a BDD anode and a stainless-steel cathode. An optimized experimental design was employed to investigate the influence of four main factors: applied current intensity (1.06 - 3.33 A), electrolysis duration (13 - 56 min), micropollutant concentration (0.26 - 8.5 µg/L), and organic matter concentration (0.86 - 29 mg/L COD). The selected matrix concentrations reflect membrane-treated municipal and low-strength industrial effluents, while current and time ranges were determined from preliminary trials to ensure effective removal within operational limits reported in the literature.Carbamazepine exhibited the most consistent removal, reaching up to 99.8% across all tested conditions. Diuron showed moderate variability, with removal ranging from 52.7% to 98.5%, influenced mainly by electrolysis time. PFOS, known for its persistence, was the most challenging compound to eliminate; nonetheless, up to 93.2% removal was achieved under optimized conditions. To further assess treatment performance, additional parameters including dissolved organic carbon (DOC), specific UV absorbance, and acute toxicity were measured. While DOC mineralization remained moderate (<20%), a decrease in UV absorbance was observed, with statistical analysis highlighting a strong correlation with organic matter concentration. Acute toxicity was assessed using Microtox® assays based on Vibrio fischeri bioluminescence inhibition. An initial increase in toxicity was observed, indicating the formation of oxidation intermediates, followed by a substantial reduction after prolonged treatment. Organic matter slightly reduced the removal of carbamazepine and diuron, whereas PFOS degradation was less affected, suggesting compound-specific degradation mechanismsOperational conditions were identified under which carbamazepine, diuron, and PFOS removals exceeded 90%, with corresponding energy consumption ranging from 0.52 to 1.46 kWh per mg of micropollutant removed over a treatment time of 50 minutes. These findings highlight the potential of BDD electrooxidation, combined with robust trace-level quantification techniques, as an energy-efficient polishing step for the removal of trace micropollutants in advanced wastewater treatment, in line with evolving regulatory standards.