Abstract

Ethylenediaminetetraacetic acid (EDTA) is a widely used chelate in household and industrial applications and behaves as a persistent compound in natural waters and in ordinary wastewater treatment plants. Due to its low degradability, Advanced Oxidation Technologies (AOTs) are considered as possible methods of EDTA abatement We report the Fe(III)-EDTA (1.34 mM) degradation by a catechol-driven Fenton reaction. In this reaction, iron availability is increased using catechol, which coordinates Fe(III) and reduces it to Fe(II) promoting the Fenton reaction. The effect of the variables catechol, Fe(III), and H2O2 concentration was studied. The time course of the degradation reaction and a comparison with a Fe(II)-Fenton reaction is also shown. The main reaction products were identified by GC-MS analysis as acetic acid, glyoxal, citric acid, glycine, nitrilotriacetic acid and N-methyl-N-(2-iminoaceryl)-1,2-dioxaethyl-2- aminoacetic acid. Fe(III)-EDTA degradation yields of 90% and TOC (Total Organic Carbon) removal of 20% were achieved. This is the first time that the degradation of a non-aromatic compound by a dihydroxybenzene-driven Fenton reaction is reported, broadening the substrate spectrum for future applications of the reaction. It is concluded that the catechol-driven Fenton reaction is a suitable way of degradation of Fe(III)-EDTA.