Optimisation of decolourisation and degradation of Reactive Black 5 dye under electro-Fenton process using Fe alginate gel beads

• Published in: Environmental science and pollution research international Vol. 20; no. 4; pp. 2172 - 2183
• Main Authors: Iglesias, O., Fernández de Dios, M. A., Rosales, E., Pazos, M., Sanromán, M. A.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.04.2013; Springer Nature B.V
• Subjects: Alginates; Alginates - chemistry; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Beads; Biological Oxygen Demand Analysis; Bioremediation; Catalysis; Chemical oxygen demand; Color removal; Coloring Agents - chemistry; Crack opening displacement; Dyes; Earth and Environmental Science; Ecotoxicology; Electrochemical Techniques; Energy consumption; Environment; Environmental Chemistry; Environmental Health; Environmental science; Experimental design; Experiments; Gels; Glucuronic Acid - chemistry; Hexuronic Acids - chemistry; Hydrogen Peroxide - chemistry; Iron; Iron - chemistry; Models, Statistical; Naphthalenesulfonates - chemistry; Optimization; Oxidation; Pollutants; Reduction; Regression Analysis; Research Article; Studies; Waste Water - chemistry; Waste Water Technology; Wastewater pollution; Water Management; Water Pollutants, Chemical - chemistry; Water pollution; Water Pollution Control; Water Purification - methods; Spain; Fe alginate gel; COD; Decolourisation; Electro-Fenton process; Reactive Black 5; CCF
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-012-1035-5

The aim of this work was to improve the ability of the electro-Fenton process using Fe alginate gel beads for the remediation of wastewater contaminated with synthetic dyes and using a model diazo dye such as Reactive Black 5 (RB5). Batch experiments were conducted to study the effects of main parameters, such as voltage, pH and iron concentration. Dye decolourisation, reduction of chemical oxygen demand (COD) and energy consumption were studied. Central composite face-centred experimental design matrix and response surface methodology were applied to design the experiments and to evaluate the interactive effects of the three studied parameters. A total of 20 experimental runs were set, and the kinetic data were analysed using first-order and second-order models. In all cases, the experimental data were fitted to the empirical second-order model with a suitable degree for the maximum decolourisation of RB5, COD reduction and energy consumption by electro-Fenton–Fe alginate gel beads treatment. Working with the obtained empirical model, the optimisation of the process was carried out. The second-order polynomial regression model suggests that the optimum conditions for attaining maximum decolourisation, COD reduction and energy consumption are voltage, 5.69 V; pH 2.24 and iron concentration, 2.68 mM. Moreover, the fixation of iron on alginate beads suggests that the degradation process can be developed under this electro-Fenton process in repeated batches and in a continuous mode.