Electrochemical Oxidation of Atrazine and Clothianidin on Bi-doped SnO2-Ti nO2 n-1 Electrocatalytic Reactive Electrochemical Membranes

Environ Sci Technol. 2018 Nov 6;52(21):12675-12684. doi: 10.1021/acs.est.8b04103. Epub 2018 Oct 11.

Abstract

This research focused on improving mineralization rates during the advanced electrochemical oxidation treatment of agricultural water contaminants. For the first time, bismuth-doped tin oxide (BDTO) catalysts were deposited on Magnéli phase (Ti nO2 n-1, n = 4-6) reactive electrochemical membranes (REMs). Terephthalic acid (TA) was used as a OH probe, whereas atrazine (ATZ) and clothianidin (CDN) were chosen as model agricultural water contaminants. The BDTO-deposited REMs (REM/BDTO) showed higher compound removal than the REM, due to enhanced OH production. At 3.5 V/SHE, complete mineralization of TA, ATZ, and CDN was achieved for the REM/BDTO upon a single pass in the reactor (residence time ∼3.6 s). Energy consumption for REM/BDTO was as much as 31-fold lower than the REM, with minimal values per log removal of <0.53 kWh m-3 for TA (3.5 V/SHE), <0.42 kWh m-3 for ATZ (3.0 V/SHE), and 0.83 kWh m-3 for CDN (3.0 V/SHE). Density functional theory simulations provided potential dependent activation energy profiles for ATZ, CDN, and various oxidation products. Efficient mass transfer and a reaction mechanism involving direct electron transfer and reaction with OH were responsible for the rapid and complete mineralization of ATZ and CDN at very short residence times.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Atrazine*
  • Electrodes
  • Guanidines
  • Neonicotinoids
  • Oxidation-Reduction
  • Thiazoles
  • Titanium
  • Water Pollutants, Chemical*

Substances

  • Guanidines
  • Neonicotinoids
  • Thiazoles
  • Water Pollutants, Chemical
  • clothianidin
  • Titanium
  • Atrazine