In this study, magnetic nanocomposites viz. SiO2@CoFe2O4 nanoparticles decorated on graphene oxide were synthesized using solvothermal and sol-gel processes. The prepared nanocomposite materials were used as magnetic adsorbents for the removal of organic and inorganic pollutants (acid black 1 dye and Cr (VI) ions as model pollutants) from aqueous solution. The structure, morphology and other physicochemical properties of nanocomposites were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), high resolution-transmission electron microscopy (HR-TEM), vibrating sample magnetometer (VSM), X-ray photo spectroscopy (XPS), zeta potential and Fourier transform infrared (FT-IR) spectroscopy. Batch mode adsorption studies were conducted with the prepared nanocomposites to determine the maximum adsorption capacity of acid black 1 dye and Cr(VI) ions as a function of contact time, pH, adsorbent dosage and initial adsorbate concentrations. Different kinetic and isotherm models were tested to describe and elucidate the adsorption mechanisms. Based on the experimental results obtained, the synthesized materials proved to exhibit considerable potential for the removal of acid black 1 and Cr(VI) ions from aqueous solution. (C) 2017 Elsevier B.V. All rights reserved.