Removal of the herbicide amitrole from water by anodic oxidation and electro-Fenton

Abstract

Here we demonstrate that an aqueous solution of the herbicide amitrole can be completely depolluted at pH 3.0 by anodic oxidation and electro-Fenton process. Anodic oxidation gives faster degradation with a borondoped diamond anode than with a Pt anode. ElectroFenton with a Pt anode and 1 mmol l 1 Fe 2+ as catalyst yields the quickest depollution. Amitrole decay always follows a pseudo first-order reaction. NO 3 and NH 4 + are accumulated in the medium during mineralization, although volatile N-products are also formed. These environmentally friendly electrochemical treatments could be applied to the remediation of wastewaters containing amitrole.

On the ability to electrogenerate hydrogen peroxide and to regenerate ferrous ions of three selected carbon-based cathodes for electro-Fenton processes

“…The development of an electrochemical process capable of producing the Fenton reagent at selected cathodes has overcome the main drawbacks represented by the need of notable amounts of reagents and the overproduction of iron-containing sludge. Due to the results obtained, this technology has experienced a fast development and its applications over the years have ranged from treatment of dyes [4][5][6], pesticides [7,8] herbicides [9], explosives [10], surfactants [11], drugs [12,13], real effluents [14][15][16] and spent adsorbent regeneration [17].…”

Mixed first and zero order kinetics in the electrooxidation of sulfamethoxazole at a boron-doped diamond (BDD) anode

“…The ensuing interest in electrolysis at BDD has led to studies of remediation of matrices such as wastewater [4,5], dye waste [6], soil [7], and removal of herbicides from waste water [8]. Some recalcitrant organics can be mineralized completely upon electrolysis at BDD anodes [4-6, 8, 9].…”

Activated carbon cloth as adsorbent and oxidation catalyst for the removal of amitrole from aqueous solution

“…V = 0.1 L, C carbon = 0.5 g/L, C H 2 O 2 = 60 mM, C AMT = 1.07 mM amount of nitrate ions, NO − 3 (exp), was similar to the theoretical amount, NO − 3 (theor), which was obtained by assuming that only two nitrogen atoms per oxidized amitrole molecule are converted to nitrate ions. The agreement between these values indicates that the rest of N is mainly converted to gaseous nitrogen compounds such as N 2 , which can be formed (Da Pozzo et al 2005) from the two proximate N atoms in the pentagonal AMT cycle (see Fig. 1).…”

“…It is a non-selective herbicide sometimes used in place of other prohibited herbicides (Oesterreich et al 1999;Catastini et al 2004;Da Pozzo et al 2005). AMT can be found at relatively high levels in surface water and can contribute to ground-water contamination via leaching, due to its high solubility.…”