Oxidation of municipal wastewater by free radicals mechanism. A UV/Vis spectroscopy study

J Environ Manage. 2017 Jun 15;195(Pt 2):186-194. doi: 10.1016/j.jenvman.2016.07.055. Epub 2016 Aug 1.

Abstract

This study investigates the oxidation of municipal wastewater (WW) by complexation with natural polyphenols having radical scavenging activity, such as (3,4,5 tri-hydroxy-benzoic acid) gallic acid (GA) in alkaline pH (>7), under ambient O2 and temperature. Physicochemical and structural characteristics of GA-WW complex-forming are evaluated by UV/Vis spectroscopy. The comparative analysis among UV/Vis spectra of GA monomer, GA-GA polymer, WW compounds, and GA-WW complex reveals significant differences within 350-450 and 500-900 nm. According to attenuated total reflectance (ATR) spectroscopy and thermogravimetric analysis (TGA), these spectra differences correspond to distinct complexes formed. This study suggests a novel role of natural polyphenols on the degradation and humification of wastes.

Keywords: Complexation; Free radicals; Municipal wastewater; Oxidation; Polyphenols.

MeSH terms

  • Free Radicals / chemistry*
  • Gallic Acid
  • Oxidation-Reduction
  • Spectrum Analysis
  • Wastewater*

Substances

  • Free Radicals
  • Waste Water
  • Gallic Acid