Photodegradation Kinetics and Color Removal of 2-(4-hydroxyphenylazo) Benzoic Acid by Advanced Oxidation Processes
Yeliz Karaman
*
Department of Chemistry, Sinop University, Sciences and Arts Faculty, 57000, Sinop, Turkey and Department of Interdisciplinary Environmental Health, Sinop University, Institute of Graduate Studies, 57000, Sinop, Turkey.
Emine Baltaci
Department of Interdisciplinary Environmental Health, Sinop University, Institute of Graduate Studies, 57000, Sinop, Turkey.
*Author to whom correspondence should be addressed.
Abstract
Degradation kinetics and color removal of 2-(4-hydroxyphenylazo)benzoic acid azo dye by the hydrogen peroxide/ultraviolet irradiation and sodium hypochlorite/ultraviolet irradiation processes were carried out in Spectroline CM-10A Model ENF-260C/FE photoreactor which has ultraviolet lamps irradiating at 254 and 365 nm wavelengths. All experimental studies were performed at room temperature in 0.04 M Britton Robinson buffer (pH 2-12). For this purpose, the degradation kinetics of 2-(4-hydroxyphenylazo)benzoic acid was investigated depending on pH, initial dye concentration and hydrogen peroxide concentration. Optimum pH and hydrogen peroxide concentration were determined as pH 10 and 3.57x10-2 M, respectively, for 3.5x10-5 M 2-(4-hydroxyphenylazo)benzoic acid. Optimum pH value in 1.55x10-3 M sodium hypochlorite medium has been found as pH 8 for 3.5x10-5 M azo dye. These methods used for degradation of dye are compared, it is concluded that sodium hypochlorite/ultraviolet irradiation and sodium hypochlorite methods are more effective than hydrogen peroxide/ultraviolet irradiation and hydrogen peroxide methods because of color removal of 83% and 64%, respectively.
Keywords: Azo dye, ultraviolet, radiation, spectrophotometer, rate constant