Degradation behaviors of Isopropylphenazone and Aminopyrine and their genetic toxicity variations during UV/chloramine treatment

Bingqi Jiang; Yajun Tian; Zichen Zhang; Ze Yin; Li Feng; Yongze Liu; Liqiu Zhang

doi:10.1016/j.watres.2019.115339

Degradation behaviors of Isopropylphenazone and Aminopyrine and their genetic toxicity variations during UV/chloramine treatment

Water Res. 2020 Mar 1:170:115339. doi: 10.1016/j.watres.2019.115339. Epub 2019 Nov 27.

Authors

Bingqi Jiang¹, Yajun Tian¹, Zichen Zhang¹, Ze Yin¹, Li Feng¹, Yongze Liu², Liqiu Zhang³

Affiliations

¹ Beijing Key Laboratory for Source Control Technology of Water Pollution, Engineering Research Center for Water Pollution Source Control and Eco-remediation, Beijing Forestry University, Beijing, 100083, China.
² Beijing Key Laboratory for Source Control Technology of Water Pollution, Engineering Research Center for Water Pollution Source Control and Eco-remediation, Beijing Forestry University, Beijing, 100083, China. Electronic address: liuyongze@bjfu.edu.cn.
³ Beijing Key Laboratory for Source Control Technology of Water Pollution, Engineering Research Center for Water Pollution Source Control and Eco-remediation, Beijing Forestry University, Beijing, 100083, China. Electronic address: zhangliqiu@163.com.

PMID: 31805497
DOI: 10.1016/j.watres.2019.115339

Abstract

Combination of ultraviolet and chloramine (i.e., UV/chloramine) treatment has been attracting increasingly attention in recent years due to its high efficiency in removing trace organic contaminants. This study investigated the degradation behaviors of two pyrazolone pharmaceuticals (i.e., Isopropyl phenazone (PRP) and Aminopyrine (AMP)) and their genetic toxicity variations during UV/chloramine treatment. The results showed that chloramine could hardly degrade PRP and AMP, while UV/chloramine greatly increased the observed first-order rate constant (k_obs) of PRP and AMP degradation. The quenching and probe experiments illustrated that the reactive chlorine species (RCS) contributed dominantly to PRP removal, and hydroxyl radical (HO^•) was the major contributor to the degradation of AMP, while the reactive amine radicals (RNS) could hardly degrade them. The overall degradation rates of PRP and AMP decreased as pH increased from 6.5 to 10. The k_obs of PRP and AMP increased along with NH₂Cl dosage increasing and reached a plateau at higher concentrations (0.2-0.5 mM). The present background carbonate (HCO₃^-, 1-10 mM), chloride (Cl^-, 1-10 mM) and natural organic matter (NOM, 5-10 mg-C L^-1) exhibited inhibition impacts on PRP and AMP degradation. In addition, the intermediates/products of PRP and AMP were identified and their general degradation pathways were proposed to be hydroxylation, deacetylation, and dephenylization. Specifically, Cl-substitution was inferred during PRP degradation, while demethylation in tertiary amine group was only observed in AMP degradation. These mechanisms including the main reactive sites of PRP and AMP were further confirmed by the frontier orbitals calculation. Moreover, the results of the genetic toxicity according to the micronucleus test of Viciafaba root tip indicated that UV/chloramine treatment could partially reduce the genetic toxicity of PRP and AMP.

Keywords: Degradation pathway; Genetic toxicity; Hydroxyl radical; Pyrazolone pharmaceuticals; Reactive chlorine species; UV/Chloramine.

MeSH terms

Aminopyrine
Antipyrine / analogs & derivatives
Chloramines
Chlorine
Kinetics
Oxidation-Reduction
Ultraviolet Rays
Water Pollutants, Chemical*
Water Purification*

Substances

Chloramines
Water Pollutants, Chemical
Aminopyrine
Chlorine
propyphenazone
Antipyrine