Degradation of Paracetamol by an UV/Chlorine Advanced Oxidation Process: Influencing Factors, Factorial Design, and Intermediates Identification

• Published in: International journal of environmental research and public health Vol. 15; no. 12; p. 2637
• Main Authors: Dao, Yen Hai, Tran, Hai Nguyen, Tran-Lam, Thien Thanh, Pham, Trung Quoc, Le, Giang Truong
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 25.11.2018; MDPI
• Subjects: Analgesics; Carbon; Chlorine; Chlorine compounds; Chromatography; Degradation; Design factors; Disinfection & disinfectants; Efficiency; Experiments; Factorial design; Gas flow; Hydrogen peroxide; Independent variables; Intermediates; Liquid chromatography; Low pressure; Mass spectrometry; Mass spectroscopy; Mathematical models; Mercury; Mercury lamps; Optimization; Organic matter; Oxidation; Oxidation process; Paracetamol; Radical groups; Response surface methodology; Scientific imaging; Sodium; Sodium hypochlorite; Variables; Water treatment; United States > US; Germany; UV/chlorine; response surface methodology; reaction kinetics; paracetamol; transformation products
• ISSN: 1660-4601; 1661-7827; 1660-4601
• DOI: 10.3390/ijerph15122637

The combination of a low-pressure mercury lamp and chlorine (UV/chlorine) was applied as an emerging advanced oxidation process (AOP), to examine paracetamol (PRC) degradation under different operational conditions. The results indicated that the UV/chlorine process exhibited a much faster PRC removal than the UV/H₂O₂ process or chlorination alone because of the great contribution of highly reactive species ( OH, Cl, and ClO ). The PRC degradation rate constant ( ) was accurately determined by pseudo-first-order kinetics. The values were strongly affected by the operational conditions, such as chlorine dosage, solution pH, UV intensity, and coexisting natural organic matter. Response surface methodology was used for the optimization of four independent variables (NaOCl, UV, pH, and DOM). A mathematical model was established to predict and optimize the operational conditions for PRC removal in the UV/chlorine process. The main transformation products (twenty compound structures) were detected by liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS).