Open AccessComparative study of electrochemical oxidation of herbicide 2,4,5-T: Kinetics, parametric optimization and mineralization pathway
Author(s) -
Hicham Zazou,
Nihal Oturan,
Hui Zhang,
Mohamed Hamdani
Publication year - 2017
Publication title -
sustainable environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.061
H-Index - 29
ISSN - 2468-2039
DOI - 10.1016/j.serj.2016.11.008
Subject(s) - mineralization (soil science) , chemistry , kinetics , aqueous solution , electrochemistry , reaction rate constant , anodic oxidation , anode , hydroxyl radical , ion , inorganic chemistry , photochemistry , radical , electrode , organic chemistry , nitrogen , physics , quantum mechanics
Oxidative degradation of herbicide 2,4,5-T was studied by electrochemical advanced oxidation processes anodic oxidation and electro-Fenton (EF) using Pt/carbon felt and BDD/carbon felt cells. The effect of main operating parameters on oxidation of 2,4,5-T and mineralization of its aqueous solution were investigated. The rate constant for oxidation of 2,4,5-T by ·≡OH was determined as (3.7 ± 0.2) × 109 M−1 s−1 using competition kinetics method. The EF process with BDD anode was shown to be very efficient reaching 94% mineralization in 3 h treatment. Based on identified aromatic intermediates, short-chain carboxylic acids, released inorganic ions and total organic carbon removal measurements, a plausible oxidation pathway for mineralization of 2,4,5-T by hydroxyl radical was proposed. In addition, the evolution of solution toxicity during treatment was monitored by Microtox method showing the formation of toxic aromatic/cyclic intermediates. The results showed also that EF process was able to remove efficiently toxic intermediates and consequently solution toxicity