Photochemical reaction kinetics and mechanistic investigations of nitrous acid with sulfamethazine in tropospheric water
Nitrous acid (HONO) is an important atmospheric pollutant that can strongly absorb ultraviolet irradiation in the region of 300–400 nm, as previously reported. Since the solar irradiance that reaches the surface of the earth has wavelengths greater than 290 nm, the photodissociation of HONO is considered the major method of hydroxyl radical formation in the troposphere. Thus, the photoinduced chemical reactivity of HONO is important. The present work investigated the reaction mechanism and kinetic parameters of HONO and sulfamethazine by using a laser flash photolysis technique and liquid chromatography-mass spectrometry. The results indicated that the sulfamethazine degradation rate was influenced by the HONO concentration and the initial concentration of sulfamethazine. Hydroxyl radicals derived from the photolysis of HONO attacked the aromatic ring of sulfamethazine to form sulfamethazine-OH adducts with a second-order rate constant of (3.8 ± 0.3) × 109 L mol−1 s−1. This intermediate would then react with HO· and oxygen molecules. The reaction rate constants of sulfamethazine-OH adducts with oxygen are (1.3 ± 0.1) × 107 L mol−1 s−1. The generation of sulfanilic acid and pyrimidine implies that the breaking down of S–N bonds of sulfamethazine and its HO adducts probably occur at the same time.
KeywordsLaser flash photolysis Sulfamethazine Nitrous acid Hydroxyl radical Reaction mechanism
The authors thank for the financial support from National Natural Science Foundation of China (NSFC) (21876038 and 51609058) for support this study.
- Barsotti F, Bartels-Rausch T, De Laurentiis E, Amman M, Brigante M, Mailhot G, Maurino V, Minero C, Vione D (2017) Photochemical formation of nitrite/nitrous acid (HONO) upon irradiation of nitrophenols in aqueous solution and in viscous secondary organic aerosol proxy. Environ Sci Technol 51:7486–7495. https://doi.org/10.1021/acs.est.7b01397 CrossRefGoogle Scholar
- García-Galán MJ, Díaz-Cruz MS, Barceló D (2012) Kinetic studies and characterization of photolytic products of sulfamethazine, sulfapyridine and their acetylated metabolites in water under simulated solar irradiation. Water Res 46:711–722. https://doi.org/10.1016/j.watres.2011.11.035 CrossRefGoogle Scholar
- Huang RJ, Yang L, Cao J, Wang Q, Tie X, Ho K, Shen Z, Zhang R, Li G, Zhu C, Zhang N, Dai W, Zhou J, Liu S, Chen Y, Chen J, O'Dowd CD (2017) Concentration and sources of atmospheric nitrous acid (HONO) at an urban site in Western China. Sci Total Environ 593:165–172. https://doi.org/10.1016/j.scitotenv.2017.02.166 CrossRefGoogle Scholar
- Kim B, Ji K, Kim C, Kang H, Lee S, Kwon B, Kho Y, Park K, Kim K, Choi K (2019) Pharmaceutical residues in streams near concentrated animal feeding operations of Korea - Occurrences and associated ecological risks. Sci Total Environ 655:408–413. https://doi.org/10.1016/j.scitotenv.2018.11.233 CrossRefGoogle Scholar
- Lee Y, Gunten UV (2010) Oxidative transformation of micropollutants during municipal wastewater treatment: comparison of kinetic aspects of selective (chlorine, chlorine dioxide, ferrate VI, and ozone) and non-selective oxidants (hydroxyl radical). Water Res 44:555–566. https://doi.org/10.1016/j.watres.2009.11.045 CrossRefGoogle Scholar
- Li X, Brauers T, Häseler R, Bohn B, Fuchs H, Hofzumahaus A, Holland F, Lou S, Lu KD, Rohrer F, Hu M, Zheng LM, Garland RM, Su H, Nowak A, Wiedensohler A, Takegawa N, Shao M, Wahner A (2012) Exploring the atmospheric chemistry of nitrous acid (HONO) at a rural site in Southern China. Atmos Chem Phys 12:1497–1513. https://doi.org/10.5194/acp-12-1497-2012 CrossRefGoogle Scholar
- Mezyk SP, Neubauer TJ, Cooper WJ, Peller JR (2007) Free-radical-induced oxidative and reductive degradation of sulfa drugs in water: absolute kinetics and efficiencies of hydroxyl radical and hydrated electron reactions. J Phys Chem A 111:9019–9024. https://doi.org/10.1021/jp073990k CrossRefGoogle Scholar
- Periša M, Babić S, Škorić I, Frömel T, Knepper TP (2013) Photodegradation of sulfonamides and their N 4- acetylated metabolites in water by simulated sunlight irradiation: Kinetics and identification of photoproducts. Environ Sci Pollut Res 20(12):8934–8946. https://doi.org/10.1007/s11356-013-1836-1 CrossRefGoogle Scholar
- Wang J, Sun Y, Feng J, Xin L, Ma J (2016) Degradation of triclocarban in water by dielectric barrier discharge plasma combined with TiO2/activated carbon fibers: effect of operating parameters and byproducts identification. Chem Eng J 300:36–46. https://doi.org/10.1016/j.cej.2016.04.041 CrossRefGoogle Scholar
- Ziemba LD, Dibb JE, Griffin RJ, Anderson CH, Whitlow SI, Lefer BL, Rappenluck B, Flynn J (2010) Heterogeneous conversion of nitric acid to nitrous acid on the surface of primary organic aerosol in an urban atmosphere. Atmos Environ 44:4081–4089. https://doi.org/10.1016/j.atmosenv.2008.12.024 CrossRefGoogle Scholar