Comparative Study of Oxidation of Some Azo Dyes by Different Advanced Oxidation Processes: Fenton, Fenton-Like, Photo-Fenton and Photo-Fenton-Like

This study makes a comparison between Fenton, Fenton-like, photo-Fenton and photo-Fenton-like treatment methods to investigate the removal of two acid dyes. The two selected acid dyes are C.I. Acid Orange 8 (AO8) and C.I. Acid Red 17 (AR17). These were chosen as model organic contaminants. The effect of operating parameters, such as amount of Fenton’s reagent (H2O2 and Fe) and Fenton’s-like reagent (H2O2 and Fe), hydrogen peroxide concentration, the two azo dyes concentration and the solution pH have been studied. Results indicated that simultaneous utilization of UV irradiation with Fenton’s and Fenton’s-like reagent increase the degradation degree (DD%) of (AO8) and (AR17). The dyes quickly lose their color, indicating that the dissolved organics have been oxidized. The dye degradation is dependent upon, concentrations of Fenton’s and Fenton’s-like reagents, H2O2 concentration, dyes concentration and the solution pH. Decolorization efficiency observed in the order of photo-Fenton>photo-Fenton-like>Fenton>Fenton-like for the two azo dyes. The color removal was found also to depend on the dye structure. Mono sulphonic azo dye (AO8) was degraded faster than disulphonic azo dye (AR17). The results indicated that the treatment of the two azo dyes with four advanced oxidation processes (AOPs) were efficient at optimum conditions. [Journal of American Science. 2010, 6(10):128-142]. (ISSN: 1545-1003).