title: Electro-oxidation of two reactive azo dyes on boron-doped diamond electrode.
abstract: Electrochemical oxidation (decolorization/degradation) of blue and red commercial reactive azo dyes was carried out on boron-doped diamond (BDD) electrode. The effect of various quantities of FeSO(4) was investigated in the electro-Fenton reaction on BDD. Progress of dyes degradation during the electrolysis and electro-Fenton reaction was monitored by UV-visible absorption and by estimation of the chemical oxygen demand (COD). Direct electrolysis showed a limiting capacity for red and blue dye removal even at high current densities, e.g. maximum red color and COD removal were 70 and 20%, respectively at 30 mA cm(-2) after 300 min. Higher red and blue color removal efficiencies were achieved by electro-Fenton oxidation. Current density of 30 mA cm(-2) in the presence of 0.05 mmol/L of FeSO(4) resulted in the red color and COD removal of 98 and 96%, respectively. The optimum FeSO(4) concentration for the electro-Fenton reaction was determined to be 0.05 mmol/L. Instantaneous current efficiency (ICE) in the presence of FeSO(4) was almost three times higher than for experiments carried out without FeSO(4).
authors: Department of Chemical and Biological Engineering, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
authors: Fares
authors: F
authors: Almomani
authors: Elena A
authors: EA
authors: Baranova
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D057919:Biological Oxygen Demand Analysis; D001895:Boron / Q000737:chemistry*; D003116:Color; D004396:Coloring Agents / Q000737:chemistry*; D018130:Diamond / Q000737:chemistry*; D004560:Electricity; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D006861:Hydrogen Peroxide / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D010084:Oxidation-Reduction; D013056:Spectrophotometry, Ultraviolet; D013997:Time Factors
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; C045076:Fenton's reagent; D018130:Diamond; D006861:Hydrogen Peroxide; D007501:Iron; D001895:Boron