Ozonation of Sitagliptin: Removal Kinetics and Elucidation of Oxidative Transformation Products

Research output: Contribution to journalArticle

Abstract

Due to the increasing use and high excretion rates, high quantities of the antidiabetic drug sitagliptin (STG) enter wastewater treatment plants (WWTPs). In conventional biological treatment, only a moderate removal was achieved, and thus, STG can be detected in WWTP effluents with concentrations in the higher ng/L range. Ozonation is a widely discussed technique for advanced wastewater treatment. In lab-scale experiments, STG showed pH-dependent removal kinetics with a maximum apparent rate constant of k ∼1 × 104 M-1 s-1 at pH ≥ 9. With an apparent rate constant of kO3 = (1.8 ± 0.7) × 103 M-1 s-1 at pH 8, STG can be considered to be readily degraded by ozonation of WWTP effluents. Ozone attacks the primary amine moiety of STG, leading to nitro-STG (TP 437) (the primary amine moiety is transformed into a nitro group). Furthermore, a diketone (TP 406) was formed, which can be further degraded by ozone. Lab-scale and pilot-scale experiments on ozonation of WWTP effluents confirmed that the ozone attack of STG was incomplete even at high ozone doses of 1.7 and 0.9 mg O3/mg DOC, respectively. These experiments confirmed that nitro-STG was formed as the main TP in the wastewater matrix. Two other TPs, TP 421c and TP 206b, were also detected, albeit with low intensities.

Details

Authors
  • Nina Hermes
  • Kevin S. Jewell
  • Per Falås
  • Holger V. Lutze
  • Arne Wick
  • Thomas A. Ternes
Organisations
External organisations
  • Federal Institute of Hydrology
  • University of Duisburg-Essen
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Environmental Engineering
Original languageEnglish
Pages (from-to)10588-10598
Number of pages11
JournalEnvironmental Science and Technology
Volume54
Issue number17
Early online date2020 Aug 11
Publication statusPublished - 2020
Publication categoryResearch
Peer-reviewedYes