In this study, the efficiency of magnetic nanoparticles for removal of hexavalent chromium from simulated electroplating wastewater was evaluated. The nanoparticles were prepared using the sol-gel method and were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), a scanning electron microscopy energy dispersive X-ray analyzer (SEM-Edx), a particle sizer and a vibrating sample magnetometer (VSM). The results showed that synthesized nanoparticles were in the size range of 40-300 rim, had purity of about 90 percent, and had magnetization of 36.5 electromagnetic unit per gram (emu/g). In conditions including pH 2, Cr (VI) concentration of 10 mg/L, nanomagnetite concentration of 1 g/L, a shaking speed of 250 rpm and a 20 minute retention time, 82% of Cr(VI) was removed. Competition from common coexisting ions such as Na(+), Ni(2+), Cu(2+), NO(3)(-), SO(4)(2-), and Cl was negligible. The adsorption data was well fitted by the Freundlich isotherm. It was concluded that magnetite nanoparticles have considerable potential for removal of Cr(VI) from electroplating wastewaters
