Removal of Acid Orange 7 from water by electrochemically generated Fenton's reagent.
The removal of azo dye Acid Orange 7 (AO7) from water was investigated by the electro-Fenton technology using electrogenerated hydroxyl radicals (OH) which leads to the oxidative degradation of AO7 up to its complete mineralization. H(2)O(2) and Fe (II) ions are electrogenerated in a catalytic way at the carbon-felt cathode. AO7 decay kinetics and evolution of its oxidation intermediates were monitored by high-performance liquid chromatography. The absolute rate constant of AO7 hydroxylation reaction has been determined as (1.20+/-0.17)x10(10)M(-1)s(-1). The optimal current value for the degradation of AO7 was found as 300 mA. AO7 degradation rate was found to decrease by increase in Fe(3+) concentration beyond 0.1mM. Mineralization of AO7 aqueous solutions was followed by total organic carbon (TOC) measurements and found to be 92%. Based on TOC evolution and identification of aromatic intermediates, short-chain carboxylic acids and inorganic ions released during treatment, a plausible mineralization pathway was proposed.
Ozcan
Ali
A
Anadolu University, Faculty of Science, Department of Chemistry, 26470 Eskişehir, Turkey. aozcan3@anadolu.edu.tr
Oturan
Mehmet A
MA
Oturan
Nihal
N
Sahin
Yücel
Y
D001391:Azo Compounds / Q000737:chemistry / Q000302:isolation & purification*; D001557:Benzenesulfonates / Q000737:chemistry / Q000302:isolation & purification*; D055664:Electrochemical Techniques; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D014873:Water Pollutants / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods
D001391:Azo Compounds; D001557:Benzenesulfonates; C045076:Fenton's reagent; D014873:Water Pollutants; D006861:Hydrogen Peroxide; D007501:Iron; C014722:2-naphthol orange