APPLICATION OF THE ELECTRO-FENTON PROCESS TO MESOTRIONE AQUEOUS SOLUTIONS: KINETICS, DEGRADATION PATHWAYS, MINERALIZATION, AND EVOLUTION OF TOXICITY

作者：Murati Minir^*; Oturan Nihal; Zdravkovski Zoran; Stanoeva Jasmina Petreska; Aaron Snezhana Efremova; Aaron Jean Jacques; Oturan Mehmet A

来源：Macedonian Journal of Chemistry and Chemical Engineering, 2014, 33(1): 119-135.

DOI：10.20450/mjcce.2014.407

• mesotrione
• electro-Fenton
• BDD
• hydroxyl radicals
• degradation mechanism
• mineralization
• toxicity

The kinetics and the mechanism of degradation of the mesotrione herbicide by three electrochemical advanced oxidation processes (EAOPs) systems, namely electro-Fenton (EF) with Pt anode (EF-Pt), anodic oxidation with BDD anode (AO), and EF-boron-doped diamond anode (EF-BDD), were investigated in acidic aqueous solutions. The degradation of mesotrione obeyed apparent first-order reaction kinetics, and its absolute rate constant value with hydroxyl radicals at pH 3.0, determined by the competitive kinetics method, was found to be 8.20 x 10(8) l mol(-1) s(-1). Fourteen different mesotrione degradation products were separated and/or identified using HPLC/MS n analyses. A rationalized scheme is proposed for the reaction pathways of mesotrione degradation in the EF process. The mesotrione mineralization yield values ranged between about 58% and 97% for a 6 h electrolysis time, according to the type of EAOP system and the electrolysis current intensity value. The evolution of the toxicity of mesotrione aqueous solutions with electrolysis time (t) was investigated during treatment by the EF-Pt and EF-BDD systems. Toxicity was measured with the Microtox (R) method, based on the luminescence inhibition of marine bacteria Vibrio fischeri. The curves of % inhibition vs. time were found to depend on the toxicity of the formed mesotrione degradation products.

• 出版日期2014