Background & objectives: Millions of liters colored effluent is daily discharged into the environment by textile industries. These effluents are usually non-biodegradable and pose a serious problem to human and aquatic life. The aim of this study was to evaluate the degradation of acid black 1 using ZnO nanoparticle doped with the CuO as a catalyst in presence of the sunlight.

Methods: This study was an applied research in which ZnO:CuO nanoparticle was synthesized and its chemical properties was evaluated by X-ray diffraction (XRD). To evaluate the photocatalytic efficiency of synthesized nanoparticles, acid black 1 was prepared and the effects of parameters such as initial dye concentrations, photocatalyst dose, and pH on the photocatalytic process were studied. The results were analyzed using kenetic equations.

Result: The results showed that the synthesized particles are heterogeneous and have nanoscale size with no agglomeration. Dye degradation decreased with increasing the dye concentration and nanoparticle dose. It is observed that photocatalysis degradation rate of dye to increase with decreasing solution pH, because hydroxyl radicals are the dominant reactive oxidant under acidic pH. It was also found that the photocatalysis degradation to follow the Langmuir-Hinshelwood kinetic equation.

Conclusion: It is concluded that the synthesized nanoparticles have a high potential for dye degradation comparing to pure ZnO and can be used as an effective photocatalyst for degradation of dyes form colored effluents.