The contribution of free radicals in paracetamol degradation by UV/NaClO
Keywords:Paracetamol, UV/Chlorine process, reactive species
UV/Chlorine is an emerging advanced oxidation process which forms several reactive species including •OH, •Cl, •OCl. This study investigated the contribution of three main free radicals: •OH, •Cl, •OCl on Paracetamol degradation under different conditions. Benzoic acid (BA), Nitro benzene (NB) and DMOB were used as probe compounds. The second rate constant of •OH, •Cl, •OCl with PRC were determined: 4.19 (±0.15) ×109 M-1s-1; 3.71 1010 M-1s-1; 3.532×109 M-1s-1, respectively. The formation of free radicals depends on pH. In particular, at pH 5: the contribution of •OH and (-•OCl, •Cl) are 45 %, 41 %, respectively, at pH 8.5, the contribution of free radicals increases up to 63 %.
Keywords. Paracetamol, UV/Chlorine process, reactive species.
Huerta-Fontela, M., M.T. Galceran, and F. Ventura, Occurrence and removal of pharmaceuticals and hormones through drinking water treatment, Water Research, 45(3), 1432-1442 (2011).
Watts, M. J. and K.G. Linden, Chlorine photolysis and subsequent OH radical production during UV treatment of chlorinated water, Water Research, 41(13), 2871-2878 (2007).
Fang J., Y. Fu, and C. Shang. The Roles of Reactive Species in Micropollutant Degradation in the UV/Free Chlorine System. Environmental Science and Technology, 48(4), 334-338 (2014).
Wu Z., J. Fang, Y. Xiang, C. Shang, X. Li, F. Meng, and X. Yang. Roles of reactive chlorine species in trimethoprim degradation in the UV/chlorine process: Kinetics and transformation pathways. Water Research, 104(Supplement C), 272-282 (2016).
B. Alfassi, Z., S. Mosseri, and P. Neta, ChemInform Abstract: Reactivities of Chlorine Atoms and Peroxyl Radicals Formed in the Radiolysis of Dichloromethane. Cheminform, 20(4), 1234-1242 (1989).
Nam S. -W., Y. Yoon, D. -J. Choi, and K. -D. Zoh. Degradation characteristics of metoprolol during UV/chlorination reaction and a factorial design optimization, Journal of Hazardous Materials, 285 (Supplement C), 453-463 (2015).
Wang, W.-L., Q.-Y. Wu, N. Huang, T. Wang, and H.-Y. Hu, Synergistic effect between UV and chlorine (UV/chlorine) on the degradation of carbamazepine: Influence factors and Radical Species. Water Research, 98(7), 143-153 (2016).
Xiang, Y., J. Fang, and C. Shang, Kinetics and pathways of ibuprofen degradation by the UV/chlorine advanced oxidation process. Water Research, 90(Supplement C), 301-308 (2016).
Sun P., W. -N. Lee, R. Zhang, and C. -H. Huang. Degradation of DEET and Caffeine under UV/Chlorine and Simulated Sunlight/Chlorine Conditions. Environmental Science & Technology, 50(24), 13265-13273 (2016).
Kong X., J. Jiang, J. Ma, Y. Yang, W. Liu, and Y. Liu, Degradation of atrazine by UV/chlorine: Efficiency, influencing factors, and products. Water Research, 90(Supplement C), 15-23 (2016).
Zhou, S., Y. Xia, T. Li, T. Yao, Z. Shi, S. Zhu, and N. Gao, Degradation of carbamazepine by UV/chlorine advanced oxidation process and formation of disinfection by-products. Environ Sci Pollut Res, 23(3), 1153-1161 (2016).
Collado N., S. Rodriguez-Mozaz, M. Gros, A. Rubirola, D. Barceló, J. Comas, I. Rodriguez-Roda, and G. Buttiglieri. Pharmaceuticals occurrence in a WWTP with significant industrial contribution and its input into the river system. Environmental Pollution, 185(Supplement C), 202-212 (2014).
Ferrer I., and E. M. Thurman. Chapter 4 - Analysis of Pharmaceuticals in Drinking Water, Groundwater, Surface Water, and Wastewater, in Comprehensive Analytical Chemistry, M. Petrovic, D. Barcelo, and S. Pérez, Editors, Elsevier, 91-128 (2013).
Andreozzi R., V. Caprio, R. Marotta, D. Vogna. Paracetamol oxidation from aqueous solutions by means of ozonation and H2O2/UV system, Water Research, 37(5), 993-1004 (2003).
Kosma C. I., D. A. Lambropoulou, and T. A. Albanis. Investigation of PPCPs in wastewater treatment plants in Greece: Occurrence, removal and environmental risk assessment. Science of The Total Environment, 466(Supplement C), 421-438 (2014).
Hamdi El Najjar, N., A. Touffet, M. Deborde, R. Journel, and N. Karpel Vel Leitner. Kinetics of paracetamol oxidation by ozone and hydroxyl radicals, formation of transformation products and toxicity, Separation and Purification Technology, 136, 137-143 (2014).