Electrochemical and sonoelectrochemical processes applied to amaranth dye degradation

Abstract

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.

Catalytic activity of Fe3−Cu O4 (0 ≤x≤ 0.25) nanoparticles for the degradation of Amaranth food dye by heterogeneous electro-Fenton process

“…Advanced Oxidation Process (AOP) is an alternative technology that has been applied for the remediation of wastewater containing dyes [13][14][15], and other organic pollutants [16][17][18], showing good performance in terms of discoloration and degradation. The electro-Fenton (E-Fenton) process stands out among the various types of AOP, as one of the most efficient technologies for the oxidation of wastewater contaminated by dyes [19][20][21].…”

Advanced oxidation processes: a review regarding the fundamentals and applications in wastewater treatment and industrial wastewater

“…A degradação do corante amaranto mediante aplicação de ultrassom associado a um sistema eletroquímico foi investigada por Steter et al (2014b). Mediante 90 min de eletrólise a 35 mA cm -2 obteve-se uma remoção de COT de 92,1% e 95,1% para os processos eletroquímico e sonoeletroquímico, com eficiência de 18,2% e 23,6%, respectivamente.…”

Removal of Endocrine Disruptors from Urban Wastewater by Advanced Oxidation Processes (AOPs): A Review

“…More recent studies have been directed towards the combination of sonolysis with other processes, such as ultraviolet irradiation [46,47], photocatalysis [48], electrochemical processes [49]. The coupling of ultrasound with other processes was found to result in synergistic effects, leading to improved removal rates as well as to partial mineralization for a wide range of contaminants.…”

“…[ 49] Environmental conditions are as important as the mass transfer of ozone in the matrix to be treated. Chan et al [60] investigated an ozone membrane reactor that synergistically combined ozone oxidation, adsorption and membrane separation to treat recalcitrant EDC pollutants in water.…”