Degradation of the typical herbicide atrazine by UV/persulfate: kinetics and mechanisms

Environ Sci Pollut Res Int. 2022 Jun;29(29):43928-43941. doi: 10.1007/s11356-022-18717-x. Epub 2022 Feb 5.

Abstract

Atrazine (ATZ), a widely used herbicide, had received a significant amount of attention due to its widespread detection in aquatic environments as well as its potential risks to human health. UV/persulfate (PS) process is an emerging technology for degrading organic pollutants in water. Thus, the degradation of ATZ by a UV/PS process was investigated in this study. The results showed that the removal rate of ATZ was 98.4% with a PS dosage of 2 mg/L and an initial ATZ concentration of 0.1 mg/L. In addition, a relatively high degradation efficiency was obtained under pH = 7. However, the addition of humic acid (HA) reduced the removal rate of ATZ. Hydroxyl radicals (•OH) and sulfate radicals (•SO4-) respectively contributed to 21.7% and 29% of the ATZ degradation. The ATZ degradation pathway was proposed, and the main reactions of ATZ in this UV/PS process included dechlorination, demethylation, and deethylation. Moreover, the toxicity of ATZ and its degradation products was assessed using the Toxicity Estimation Software Tool (TEST), and the results showed that the toxicity of the ATZ solution was reduced after the UV/PS process. These results indicate that UV/PS shows good promise as a remediation technique for the treatment of persistent herbicides such as ATZ in contaminated water.

Keywords: Atrazine; Degradation efficiency; Degradation mechanism; Radicals; Ultraviolet/persulfate process.

MeSH terms

  • Atrazine* / analysis
  • Herbicides*
  • Humans
  • Kinetics
  • Oxidation-Reduction
  • Ultraviolet Rays
  • Water
  • Water Pollutants, Chemical* / analysis
  • Water Purification* / methods

Substances

  • Herbicides
  • Water Pollutants, Chemical
  • Water
  • Atrazine