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Electrochemical and sonoelectrochemical degradation of Allura Red and Erythrosine B dyes with Ti-PbO2 anode

2021; Elsevier BV; Volume: 889; Linguagem: Inglês

10.1016/j.jelechem.2021.115212

1873-2569

Sabrine Ben Kacem, Sourour Chaâbane Elaoud, Antonio Maria Asensio, Marco Panizza, Davide Clematis,

Advanced Photocatalysis Techniques

The degradation of food dyes such as Allura Red AC and Erythrosine B is studied using electrochemical (ECh) and sonoelectrochemical (SECh) oxidation. The electrochemical cell has a Ti/PbO2 anode and stainless steel cathode. SECh process used an ultrasound transducer with a frequency of 40 kHz. The influence of process parameters on removal performance is examined, such as the effect of US, current intensity, stirring rate, nature and concentration of supporting electrolytes (Na2SO4, NaCl, Na2CO3) and energy consumptions are discussed as a function of chemical oxygen demand removal. The results show that ultrasonic irradiation promotes the removal of organic matter due to the activation of oxidant species. The synergistic index gives useful information about the effect of ultrasounds, which have a higher relevance working in mild conditions (low current intensity, stirring rate and supporting electrolyte concentrations). The most relevant impact has been detected in the presence of chloride, which promotes the removal of pollutants and chemical oxygen demand (COD), with a substantial reduction of the required time. On the other hand, bicarbonate ions in solution had a detrimental effect on both processes. Nevertheless, in all cases tested in this paper, this index has a value greater than one, pointing out a positive influence of ultrasound application. Then, the integration of such technology with electrochemical advanced oxidation processes can improve the removal of Allura Red and Erythrosine B with a PbO2-based anode.