New insights into the anodic oxidation and electrocoagulation using a self-gas stirred reactor: A comparative study for synthetic C.I Reactive Violet 2 wastewater

• Published in: Journal of cleaner production Vol. 167; pp. 432 - 446
• Main Authors: El-Ashtoukhy, E-S.Z., Amin, N.K., Abd El-Latif, M.M., Bassyouni, D.G., Hamad, H.A.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 20.11.2017
• Subjects: COD reduction; Decolorization; Electrochemical oxidation; Electrocoagulation; Hydroxyl radicals; Wastewater treatment; Hydroxyl radicals; COD reduction; Decolorization; Electrocoagulation; Wastewater treatment; Electrochemical oxidation
• ISSN: 0959-6526; 1879-1786
• DOI: 10.1016/j.jclepro.2017.08.174

This work deals with the studying the role of oxidizing agents through the comparative behavior of two anodic oxidation and electrocoagulation processes as a technological alternative for the decolorization of C.I Reactive Violet 2 dye. A typical mono azo dye is tested by using a new fixed bed batch self-gas stirred electrochemical cell. The optimum condition is obtained as current density = 79 A/m2, initial dye concentration = 100 mg/L, pH 7, and NaCl concentration = 2 g/L, for which the predicted color removal efficiencies are 94.71 and 99.8%, rate constants of 0.072 and 0.179 min−1 with half life time 9.36 and 3.87 min and achieved in 60 and 45 min as a time of reaction for anodic oxidation and electrocoagulation, respectively. The most enormous technique is electrocoagulation, achieving an almost total decolorization faster than anodic oxidation. Although the mechanisms of two processes are various manners, the results show that the pseudo-first-order rate kinetic oxidation that is fitted the best correlation of the decolorization rate of the dye. The relationship between decolorization and chemical oxygen demands reduction is finally discussed. This work indicates that two processes generally utilized in chemical industry and are a promising alternative for the treatment of the textile wastewater containing reactive dyes. [Display omitted] •Faster decolorization of Reactive Violet 2 dye by two processses.•A new self gas stirred reactor for degradation of reactive dye by two processes.•Various operational conditions affect on the oxidation efficiency.•Up to 100% decolorization by the most powerful EC process.•Synergy between coagulation and oxidation by OH and active chlorine species.