Degradation of acesulfame in UV/monochloramine process: Kinetics, transformation pathways and toxicity assessment

Chi Hang Chow, Japhet Cheuk Fung Law, Kelvin Sze-Yin Leung*

*Corresponding author for this work

Research output: Contribution to journalJournal articlepeer-review

19 Citations (Scopus)
22 Downloads (Pure)


UV/monochloramine (UV/NH2Cl) is an emerging advanced oxidation process that can generate various reactive species like reactive chlorine species (RCS) and hydroxyl radicals for micropollutant removal. This study investigated the potential toxicity of transformation products resulting from UV/NH2Cl treatment of acesulfame (ACE), as an example of micropollutant, found in worldwide aquatic environment. Compared with UV photolysis and chloramination, the UV/NH2Cl process more effectively degraded ACE. The transformation products of ACE treated with the UV/NH2Cl process were identified and characterized with high resolution mass spectrometry. The formation of chlorinated-TPs indicated the role of RCS in UV/NH2Cl transformation even though UV photolysis was predominantly responsible for the ACE degradation. The Vibrio fischeri bioluminescence inhibition assay revealed a higher toxicity of TPs derived from UV/NH2Cl than from UV photolysis. The increased toxicity could be attributed to most of the generated chlorinated-TPs (Cl-TPs), in particular those halo-alcohols. The ECOSAR program predicts that halo-alcohol TPs are more toxic than their non-chlorinated analogues and other Cl-TPs. This study provides insight into the important role of reactive species in the micropollutants’ transformation of UV/NH2Cl process. It further provides information relevant to the potential risk when applying the process for micropollutant removal in water treatment.

Original languageEnglish
Article number123935
JournalJournal of Hazardous Materials
Early online date13 Sept 2020
Publication statusPublished - 5 Feb 2021

Scopus Subject Areas

  • Environmental Engineering
  • Environmental Chemistry
  • Waste Management and Disposal
  • Pollution
  • Health, Toxicology and Mutagenesis

User-Defined Keywords

  • acesulfame
  • Advanced Oxidation Process
  • toxicity
  • transformation products
  • UV/monochloramine


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