BACKGROUNDThe extensive use of dyes in textile industries leads to discharge of dye effluents into water bodies which causes problem to human and aquatic life. In this regard, magnetic nanospinels having formula MFe2O4 (M=Cu, Zn, Ni and Co) were developed and characterized by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), powder x-ray diffraction (XRD) and diffuse reflactance spectra (DRS). The activity of all the ferrites as heterogeneous Fenton and photo-Fenton catalysts was evaluated by degradation of Remazol Black 5 (RB5) which is used in the textile industry to dye cotton. RESULTSThe optimum reaction conditions for the degradation reactions were 0.50 g L-1 ferrite, pH 2.5, H2O2 8 mmol L-1 and dye 50 mg L-1. Among the four ferrites CuFe2O4 was found to be best (k=0.228 min(-1)) which might be attributed to coupling between Fe3+/Fe2+ and Cu+/Cu2+ redox pairs thus generating more efficient Fenton reagent. Reusability of all the catalysts after magnetic separation was also tested over four cycles. CONCLUSIONAll the spinel ferrites had good photodegradation ability and recyclability demonstrating their use to remove organic pollutants from wastewater. (c) 2014 Society of Chemical Industry