Abstract:
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
nm, 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+, Ni2+, Cu2+, NO3 -, SO4 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.

Mohammad Mehdi Amin, Abbas Khodabakhshi, Morteza Mozafari, Bijan Bina, Soleiman Kheiri