Textile industries discharge large quantity of colored wastewater which is harmful to the ecosystem. In this study, two kinds of dyes were investigated: the mono azo Acid Orange 7 (AO7) and diazo Reactive Green 19 (RG19). The photocatalytic degradation of single (AO7, RG19) azo dye and binary (AO7 and RG19 mixture) azo dye aqueous solutions were photocatalyzed by commercial titanium dioxide (TiO2, P25) under solar light irradiation. The objectives of this study are to compare the photocatalytic degradation between single and binary azo dye aqueous solution and to study the various parameters such as effect of different initial azo dye concentration, different initial azo dye pH values, compare the adsorption capacity of azo dyes between with and without solar light irradiation that influence the photocatalytic activities of single and binary azo dye aqueous solution on TiO2 suspension. The results showed that photocatalytic degradation of AO7 and RG19 in single azo dye aqueous solution was faster than binary azo dye solution under solar light irradiation process. Chemical oxygen demand results revealed that complete mineralization could be achieved for both AO7 and RG19 azo dyes under solar light irradiation within 22 hours time intervals.
- adsorption capacity
- azo dyes
- photocatalytic degradation
- solar light
- titanium dioxide
- First received 22 February 2015.
- Accepted in revised form 9 May 2015.
- © IWA Publishing 2015