In the current paper, the nanoparticles of cobalt iron oxide doped by chromium (CIC) of (CrxCoFe2-xO4) formula were prepared by sol-gel method using the nitrate salts of the elements composed of this nanomaterial. The characteristic properties of CIC nanoparticles prepared were determined using X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) in addition to scanning electron microscopy (SEM) and also examination of the surface area (BET). These tests showed that the CIC nanoparticle prepared was in a pure phase, in addition to having various functional groups; moreover their structural framework includes multiple pores, which was the reason for the high surface area, reached to 223.36 m2.g-1. The prepared CIC nanoparticle was applied as an adsorbent to recover the malachite green dye from aqueous contaminated solutions in a batch mode adsorption unit and under different operating conditions. Designing factors used to determine the efficiency of the CIC as an adsorption media for the organic dye included the acidic function (pH), contact time and amount of nanomaterial CIC. The obtained practical results showed that the removal efficiency of the malachite green dye using CIC nanoparticle was 88.519% at 50 ppm of the initial concentration of the contaminated solution and that the percentage removal was directly proportional to the amount of adsorbent, contact time and acidic function.
