Degradation of the Dye Reactive Blue 4 by Coupled Photoassisted Electrochemistry at DSA^®-Type Electrode

Abstract

We investigated the photoelectrochemical oxidation of the dye Reactive Blue 4 in the presence of a DSA ® -type electrode of nominal composition Ti/Ru 0.3 Ti 0.7 O 2 under ultraviolet radiation, aiming to enhance the degradation yields of this dye. We conducted the photoelectrocatalytic treatment under galvanostatic control, using an 80 W mercury vapor lamp as the UV source. We also compared unassisted electrooxidative processes and photocatalytic processes with photoelectrochemical oxidation, to gain better insight into the employed advanced oxidation processes and to evaluate their applicability. The photoelectrooxidative process conducted at 37.8 mA cm -2 promoted fast color removal in the tested solution. The chemical oxygen demand and total organic carbon decreased by approximately 64.7 and 42.7%, respectively. High performance liquid chromatography, gas chromatography coupled to mass spectrometry helped to identify the intermediate compounds produced along the photoelectrochemical process, namely phthalic anhydride, phthalimide, phthalide, 1,3-indanone, and benzoic acid.

Electrochemical decolorization of Rhodamine B dye: Influence of anode material, chloride concentration and current density

“…In comparison to other electrodes, DSAs have high chemical and mechanical, and higher current density. Many workers have been used DSA as an efficient material for degradation of glyphosate formulations [24], Reactive Blue 4 [25], Methyl orange [26] and mixtures of phenol-formaldehyde [27]. In these studies, the efficiency depended on several parameters, like pollutant concentration, initial pH, supporting electrolyte, cathode material, current density and temperature.…”

Degradation of Anthraquinone Dyes from Effluents: A Review Focusing on Enzymatic Dye Degradation with Industrial Potential

“…This shows the lack of control over the dye degradation reactions and the existence of spontaneous reactions that can lead to the same lower fragments via multiple paths. , With regards to the auxiliary groups present on the dye structures (such as amino-groups, sulfone-groups, halogen-groups), mapping down their degradation pathway was more difficult. Research examples either did not identify further degradation past the original rupture from the dye structure, ,, or identified big fragments and even polymerized by-products …”

“…These fragments were mainly produced by the cleavage and subsequent degradation of the anthraquinone ring through various steps. In some cases it was noted that different dyes (Reactive Blue 19 213 and Reactive Blue 4 214 ) treated with the same method led to the same degradation products (as derived by the AQ ring). This observation could be an indication of some control over the end products if a specific method is applied.…”

Application of impregnated biocarbon produced from soybean hulls in dye decolorization

“…Structurally, RB4 consists of a dichlorotriazine group and anthraquinone chromophore. Due to its high water solubility and low biodegradability, wastewater treatment is required in processes using this dye [5,6].…”