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• ZC 1.3 F 0.7 O-5C was prepared from waste ferrous sulfate by microwave assisted method. • Focused beam reflection meter was investigate the agglomeration of catalyst. • ZC 1.3 FO-5C had high stability and low ion impregnation rate. • Degradation intermediates were determined and degradation pathways were proposed. Cobalt-doped ZnFe 2 O 4 supported on rice husk carbon (RHC) has been prepared by a microwave-assisted method as a catalyst for the degradation of bisphenol A (BPA) by persulfate (PS) oxidation. Ferrite is a good absorbing material, RHC contains abundant channels, which provide channels for microwaves(MW) reflecting and scattering, and accelerate the synthesis of ZC 1.3 FO. In addition, the polarization and synergistic effect of the contact interface between the two phases is enhanced, which not only improves the dispersity of the magnetic material, but also enhances electron delocalization in the mixed material, promoting electron transfer between Co3+/Co2+ and Fe3+/Fe2+, and improving the catalytic activity. Our results have shown the degradation rate of BPA by ZnCo 1.3 Fe 0.7 O 4 -50 wt%RHC (ZC 1.3 FO-5C) (0.0697 L/mg min) to be 28 times higher than that by ZC 1.3 FO (0.00251 L/mg min), and the extents of leaching of cobalt and iron were lower than 45 μg/L. Particle video microscopy (PVM) have been used to confirm improved dispersion of composite particles compared to that of a single catalyst during degradation. Free radical quenching experiments, electron paramagnetic resonance (EPR), and X-ray photoelectron spectroscopy (XPS) have confirmed that BPA degradation was caused by the synergistic action of non-free radical and free radical pathways. Intermediates have been identified by electrospray ionization mass spectrometry (ESI-MS), on the basis of which a degradation pathway of BPA by activated PS oxidation in the presence of ZC 1.3 FO-5C is proposed. In brief, a ZC 1.3 FO-5C composite has been prepared by a microwave method to activate PS for the degradation of BPA, realizing the resource utilization of waste ferrous sulfate derived from titanium dioxide production, providing a new concept for the degradation of organic pollutants. [ABSTRACT FROM AUTHOR]

Graphical abstract Mechanism of the activation on PS by NiFe 0.7 Co 1.3 O 4 -RGO for the degradation of BPA. Highlights • Magnetic NiFe 0.7 Co 1.3 O 4 -RGO 1 was fabricated via a simple hydrothermal route. • Bisphenol A was completely removed by NiFe 0.7 Co 1.3 O 4 -RGO/PS in 25 min. • Co doping enhances the activity of the catalyst for persulfate activation. • BPA degradation is achieved partly via nonradical pathway promoted by RGO. • The influence of reaction parameters for the mineralization of BPA was evaluated. Abstract A simple route was reported for the synthesis of reduced graphene oxide (RGO) based NiFe 2−x Co x O 4 nanocomposite (NiFe 2−x Co x O 4 -RGO), a catalyst to activate persulfate (PS) for the degradation of bisphenol A (BPA). The crystalline structure and morphology of the composite were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). It is confirmed that spherical NiFe 2−x Co x O 4 nanoparticles with a size around 14 nm are uniformly anchored on RGO sheets. Compared with recently reported catalysts, NiFe 0.7 Co 1.3 O 4 -RGO 1 exhibits impressively higher catalytic activity, leading to much faster degradation of BPA with pretty less PS used. Moreover, the excellent catalytic performance can be maintained in a wide range of pH. The radical scavenging study and EPR experiments indicate that free radical, surface-bound radical and nonradical processes are involved in the degradation of BPA. In addition, the degradation of various organic contaminants other than BPA were also carried out, indicating that NiFe 0.7 Co 1.3 O 4 -RGO 1 /PS system has higher catalytic activity toward BPA. [ABSTRACT FROM AUTHOR]