Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6305972 | Chemosphere | 2017 | 8 Pages |
â¢Effective removal of aspartame (ASP) by electro-Fenton process.â¢Effect of current and catalyst concentration on mineralization rate of ASP.â¢Determination of rate constant for oxidation of ASP by OH as 5.23 Ã 109 Mâ1 sâ1.â¢Nitrogen present in ASP is released as oxamic acid and nitrate/ammonium ions.â¢Toxicity assessment by Microtox highlights detoxification of treated solution.
The degradation and mineralization of aspartame (ASP) in aqueous solution were investigated, for the first time, by electrochemical advanced oxidation processes (EAOPs) in which hydroxyl radicals were formed concomitantly in the bulk from Fenton reaction via in situ electrogenerated Fenton's reagent and at the anode surface from the water oxidation. Experiments were performed in an undivided cylindrical glass cell with a carbon-felt cathode and a Pt or boron-doped diamond (BDD) anode. The effect of Fe2+ concentration and applied current on the degradation and mineralization kinetics of ASP was evaluated. The absolute rate constant for the reaction between ASP and OH was determined as (5.23 ± 0.02) Ã 109 Mâ1 sâ1 by using the competition kinetic method. Almost complete mineralization of ASP was achieved with BDD anode at 200 mA constant current electrolysis. The formation and generation of the formed carboxylic acids (as ultimate end products before complete mineralization) and released inorganic ion were monitored by ion-exclusion high performance liquid chromatography (HPLC) and ion chromatography techniques, respectively. The global toxicity of the treated ASP solution during treatment was assessed by the Microtox® method using V. fischeri bacteria luminescence inhibition.
Graphical abstractDownload high-res image (129KB)Download full-size image