The plating industry is one of the causes of hexavalent chromium Cr (VI) pollution in surface water, raising problems

for human health and other living things. In this study, we synthesized CoFe 2 O 4 magnetic nanoparticles and coated them

with cetyltrimethylammonium bromide (CTAB), a commonly used cationic surfactant, to form CTAB/CoFe 2 O 4 magnetic

nanocomposite for Cr (VI) adsorptive removal application from aqueous solution. Characteristic properties of CTAB/

CoFe 2 O 4 were examined using scanning electron spectrometry, surface area apparatus, X-ray diff ractometer, Fourier

transform infrared spectrometry, zeta potential analyzer, and vibrating sample magnetometer. The CTAB/CoFe 2 O 4 had

superparamagnetic properties, being easily isolated from an aqueous solution and well regenerated by an external magnet.

Besides, the CTAB molecules anchored onto the Co 2 FeO 4 nanoparticle surfaces could increase the positive charge

and thus facilitate the electrostatic interaction with the Cr (VI) anions. Accordingly, the CTAB/CoFe 2 O 4 reached the Cr

(VI) adsorption effi ciency of 89%, two times higher than the pure CoFe 2 O 4 , at an optimal pH of 2, an adsorbent dose of

1 g/L, and an initial Cr (VI) concentration of 10 mg/L. The CTAB/CoFe 2 O 4 magnetic nanocomposite would promise a

high potential for Cr (VI) treatment from plating wastewater with simple separation, good adsorption capacity, and an

inexpensive, nontoxic production process.