Electrochemical degradation of acetaminophen in urine matrices: Unraveling complexity and implications for realistic treatment strategies

• Published in: Water research (Oxford) Vol. 261; p. 122034
• Main Authors: Felisardo, Raul José Alves, Brillas, Enric, Boyer, Treavor H., Cavalcanti, Eliane Bezerra, Garcia-Segura, Sergi
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.09.2024
• Subjects: Acetaminophen; Dimensional Stable Anode (DSA); Effluent strategies; Electrochemical oxidation; Fresh real urine; Hydrolyzed real urine; Hydrolyzed real urine; Acetaminophen; Fresh real urine; Electrochemical oxidation; Dimensional Stable Anode (DSA); Effluent strategies
• ISSN: 0043-1354; 1879-2448; 1879-2448
• DOI: 10.1016/j.watres.2024.122034

•Effective treatment of acetaminophen in synthetic urine at 48 mA cm−2 via DSA.•Acetaminophen removal competes with organic constituents in complex urine matrices.•Lower degradation in fresh real urine than in synthetic and hydrolyzed real urine.•Slow mineralization, low urea degradation and/or carboxylic acids accumulation.•Detected acetic, tartaric, maleic, and oxalic acids, and released NO3−, NO2−, NH4+. Urine has an intricate composition with high concentrations of organic compounds like urea, creatinine, and uric acid. Urine poses a formidable challenge for advanced effluent treatment processes following urine diversion strategies. Urine matrix complexity is heightened when dealing with pharmaceutical residues like acetaminophen (ACT) and metabolized pharmaceuticals. This work explores ACT degradation in synthetic, fresh real, and hydrolyzed real urines using electrochemical oxidation with a dimensional stable anode (DSA). Analyzing drug concentration (2.5 - 40 mg L−1) over 180 min at various current densities in fresh synthetic effluent revealed a noteworthy 75% removal at 48 mA cm−2. ACT degradation kinetics and that of the other organic components followed a pseudo-first-order reaction. Uric acid degradation competed with ACT degradation, whereas urea and creatinine possessed higher oxidation resistance. Fresh real urine presented the most challenging scenario for the electrochemical process. Whereas, hydrolyzed real urine achieved higher ACT removal than fresh synthetic urine. Carboxylic acids like acetic, tartaric, maleic, and oxalic were detected as main by-products. Inorganic ionic species nitrate, nitrite, and ammonium ions were released to the medium from N-containing organic compounds. These findings underscore the importance of considering urine composition complexities and provide significant advancements in strategies for efficiently addressing trace pharmaceutical contamination. [Display omitted]