In this paper, magnetic zinc ferrite (ZnFe2O4) nanoparticle was synthesized and its photocatalytic dye degradation ability from colored wastewater was studied. Reactive Red 198 (RR198) and Reactive Red 120 (RR120) were used as model dyes. The characteristics of ZnFe2O4 were investigated using Fourier transform infrared (FTIR), X-ray diffraction (XRD) and scanning electron microscope (SEM). Photocatalytic dye degradation by ZnFe2O4 was studied by UV-vis spectrophotometer and ion chromatography (IC). The effects of ZnFe2O4 dosage, initial dye concentration and salt on dye degradation were evaluated. Formate, acetate and oxalate anions were detected as dominant aliphatic intermediate. Inorganic anions (nitrate and sulfate anions) were detected as dye mineralization products. The results indicated that ZnFe2O4 could be used as a magnetic photocatalyst to degrade dyes from colored wastewater. (C) 2013 Elsevier Ltd. All rights reserved.