Degradation of acrylamide by the UV/chlorine advanced oxidation process

Chemosphere. 2017 Nov:187:268-276. doi: 10.1016/j.chemosphere.2017.08.085. Epub 2017 Aug 19.

Abstract

The degradation of acrylamide (AA) during UV/chlorine advanced oxidation process (AOP) was investigated in this study. The degradation of AA was negligible during UV irradiation alone. However, AA could be effectively degraded and mineralized during UV/chlorination due to the generation of hydroxyl radicals (OH). The degradation kinetics of AA during UV/chlorination fitted the pseudo-first order kinetics with the rate constant between AA and OH radicals being determined as 2.11 × 109 M-1 s-1. The degradation rate and mineralization of AA during UV/chlorination were significantly promoted at acidic conditions as well as increasing chlorine dosage. The volatile degradation products of AA during UV/chlorination were identified using gas chromatography-mass spectrometry and the degradation pathways were then proposed accordingly. The formation of disinfection by-products (DBPs) in Milli-Q water and tap water during UV/chlorination of AA was also investigated. The DBPs included chloroform, dichloroacetonitrile, trichloroacetonitrile, 2,2-dichloroacetamide and 2,2,2-trichloroacetamide. Furthermore, the variations of AA degradation during UV/chlorination in different real water samples were evaluated.

Keywords: Acrylamide; Flocculants; Hydroxyl radicals; UV/chlorination; Water treatment.

MeSH terms

  • Acetamides / chemistry
  • Acrylamide / analysis*
  • Acrylamide / chemistry
  • Chlorine / chemistry
  • Chloroform / analysis
  • Disinfection / methods
  • Halogenation
  • Hydroxyl Radical
  • Ions
  • Kinetics
  • Models, Chemical*
  • Oxidation-Reduction
  • Ultraviolet Rays*
  • Water Pollutants, Chemical / analysis
  • Water Pollutants, Chemical / chemistry*
  • Water Purification / methods

Substances

  • Acetamides
  • Ions
  • Water Pollutants, Chemical
  • Acrylamide
  • Hydroxyl Radical
  • Chlorine
  • Chloroform
  • 2,2-dichloroacetamide