Electrochemical and sonoelectrochemical processes applied to amaranth dye degradation.

Juliana R Steter, Willyam R P Barros, Marcos R V Lanza, Artur J Motheo

Chemosphere 2014 Dec

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Amaranth dye is an organic compound largely used in the food and beverage industries with potential toxicity effects on humans. It can be found as a pollutant species in aquatic environments and has been classified as an endocrine disruptor. This study describes amaranth degradation upon ultrasonication associated with an electrochemical system that uses a boron-doped diamond anode BDD, defined as a sonoelectrochemical process. Ninety-minute electrolyses were performed using current densities in the 10-50 mA cm(-2) range, and the concentration decay, pH, energy and current efficiencies, as well as the discoloration rate were evaluated. The amaranth concentration decayed as a function of electrolysis time and the reactions obeyed pseudo first-order kinetics, with an apparent constant rate between 10(-1) and 10(-3)min(-1). The electrochemical and sonoelectrochemical processes at 35 mA cm(-2) yielded TOC removal values between 92.1% and 95.1% respectively, after 90 min. Current efficiency values obtained for both processes were 18.2% and 23.6%. Exhaustive 5h electrolysis was performed and the degradation products were identified by HPLC-MS. A mechanism for the degradation of amaranth was proposed based on an analysis of the aromatic and aliphatic intermediates. Copyright © 2014 Elsevier Ltd. All rights reserved.

Citation

Juliana R Steter, Willyam R P Barros, Marcos R V Lanza, Artur J Motheo. Electrochemical and sonoelectrochemical processes applied to amaranth dye degradation. Chemosphere. 2014 Dec;117:200-7