In this study, the photocatalytic degradation of batik wastewater in the presence of zinc oxide (ZnO) as photocatalyst was
investigated. The effect of various operating parameters, such as pH of batik wastewater, catalyst dosage and aeration
on the photocatalytic degradation process, was examined. The mineralization of batik wastewater was also evaluated
through chemical oxygen demand analysis. The decolorization of batik wastewater was enhanced at acidic conditions
(pH3) which was 88.2% after 10 h irradiated under solar light, meanwhile its mineralization was 286 mg/L after 12 h
irradiation time. The data obtained for photocatalytic degradation of batik wastewater was well fitted with the LangmuirHinshelwood
kinetic model. It can be concluded that batik wastewater could be decolorized and mineralized under solar
light irradiation with presence of ZnO.