Radiolytic degradation of gallic acid and its derivatives in aqueous solution

R. Melo, J. P. Leal, E. Takács, L. Wojnárovits

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

Polyphenols, like gallic acid (GA) released in the environment in larger amount, by inducing some unwanted oxidations, may constitute environmental hazard: their concentration in wastewater should be controlled. Radiolytic degradation of GA was investigated by pulse radiolysis and final product techniques in dilute aqueous solution. Subsidiary measurements were made with 3,4,5-trimethoxybenzoic acid (TMBA) and 3,4,5-trihydroxy methylbenzoate (MGA). The hydroxyl radical and hydrogen atom intermediates of water radiolysis react with the solute molecules yielding cyclohexadienyl radicals. The radicals formed in GA and MGA solutions in acid/base catalyzed water elimination decay to phenoxyl radicals. This reaction is not observed in TMBA solution. The hydrated electron intermediate of water decomposition adds to the carbonyl oxygen, the anion thus formed protonates on the ring forming cyclohexadienyl radical or on the carbonyl group forming carbonyl centred radical. The GA intermediates formed during reaction with primary water radicals in presence of oxygen transform to non-aromatic molecules, e.g., to aliphatic carboxylic acids.

Original languageEnglish
Pages (from-to)1185-1192
Number of pages8
JournalJournal of Hazardous Materials
Volume172
Issue number2-3
DOIs
Publication statusPublished - Dec 30 2009

Fingerprint

Gallic Acid
aqueous solution
Derivatives
Degradation
Radiolysis
degradation
Acids
Water
acid
Pulse Radiolysis
Oxygen
Molecules
Polyphenols
Waste Water
Carboxylic Acids
Hydroxyl Radical
Anions
Hydrogen
Hazards
Wastewater

Keywords

  • Gallic acid
  • Polyphenols
  • Radiolysis
  • Radiolytic degradation
  • Water purification

ASJC Scopus subject areas

  • Health, Toxicology and Mutagenesis
  • Pollution
  • Waste Management and Disposal
  • Environmental Chemistry
  • Environmental Engineering

Cite this

Radiolytic degradation of gallic acid and its derivatives in aqueous solution. / Melo, R.; Leal, J. P.; Takács, E.; Wojnárovits, L.

In: Journal of Hazardous Materials, Vol. 172, No. 2-3, 30.12.2009, p. 1185-1192.

Research output: Contribution to journalArticle

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