Bioelectrochemical chlorate reduction by Dechloromonas agitata CKB

Bioresour Technol. 2020 Nov:315:123818. doi: 10.1016/j.biortech.2020.123818. Epub 2020 Jul 13.

Abstract

Chlorate has been described as an emerging pollutant that compromises water sources. In this study, bioelectrochemical reactors (BERs) using Dechloromonas agitata CKB, were evaluated as a sustainable alternative for chlorate removal. BERs were operated under flow-recirculation and batch modes with an applied cell-voltage of 0.44 V over a resistance of 1 kΩ. Results show chlorate removal up to 607.288 mg/L. After 115 days, scanning electron microscopy showed biofilm development over the electrodes, and electrochemical impedance spectroscopy confirmed the biocatalytic effect of CKB. The theoretical chlorate bioreduction potential (ε° = 0.792 V) was proven, and a kinetic study indicated that 6 electrons were involved in the reduction mechanism. Finally, a hypothetical bioelectrochemical mechanism for chlorate reduction in a BER was proposed. This research expands upon current knowledge of novel electrochemically active microorganisms and widens the scope of BER applications for chlorate removal.

Keywords: Biocathode; Bioelectrochemical reactor; Chlorate; Dechloromonas agitata; Microbial Electrochemical Technology.

MeSH terms

  • Betaproteobacteria
  • Chlorates*
  • Electrodes
  • Electrons*
  • Oxidation-Reduction

Substances

  • Chlorates

Supplementary concepts

  • Dechloromonas agitata