Electrochemical degradation of indigo carmine by low voltage pulse electrolysis

Wei Zhan, Yaguang Du, Jirong Lan, Runlong Lei, Ruiyue Li, Dongyun Du, Tian C. Zhang

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

Degradation of indigo carmine (IC) in aqueous solution via electrochemical oxidation (EO) was investigated by low voltage pulse electrolysis. The effects of experimental operating variables on total organic carbon(TOC) removal efficiency were studied, including initial pH, NaCl addition, charging voltage/frequency, and initial concentration of IC. The IC removal efficiency (in TOC) was higher under highly acidic or alkaline conditions, increased with the NaCl addition and an increase in charging voltage or frequency, but decreased with an increase in the initial concentration of IC. Intermediates formed during the degradation such as isatin-5-sulfonic acid (m/z = 226), 2-amino-α-oxo-5-sulfo-benzeneacetic acid (m/z = 242), 2-amino-5-sulfobenzoic acid (m/z = 198), and 2-amino-5-hydroxybenzoic acid (m/z = 152) were identified, on the basis of which a degradation pathway was proposed for the electrochemical degradation of IC in aqueous solution. The electrical energy consumption (Ec) in electrocatalytic oxidation was 159 kWh/kgTOC and the current efficiency is 15.3%. The EO technique on the basis of low voltage pulse electrolysis may be a promising approach to treatment of textile wastewater.

Original languageEnglish (US)
Article number118006
JournalJournal of Molecular Liquids
Volume348
DOIs
StatePublished - Feb 15 2022

Keywords

  • Electrochemical degradation
  • Indigo carmine
  • Low voltage pulse electrolysis

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics
  • Spectroscopy
  • Physical and Theoretical Chemistry
  • Materials Chemistry

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