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Abstract
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A new magnetic nanocomposite (MNC) was prepared by grafting 3-chloropropyltrimethoxysilane
and melamine (CPMSi-Mel) onto the surface of Fe3O4@TiO2 nanoparticles. Then, nanocomposite of
chloroacetyl-chitosan (CACS) and (Fe3O4@TiO2-CPMSi-Mel) was fabricated from coprecipitation of
CACS on the (Fe3O4@TiO2-CPMSi-Mel) nanoparticles. The synthesized MNC was characterized by
Fourier transform infrared spectroscopy, X-ray diffraction analysis, field emission scanning electron
microscopy, transmission electron microscopy, CHN elemental analysis, thermogravimetric analysis,
and vibrating sample magnetometer. The ability of MNC for removing heavy metal ion (Cd2+)
from polluted water was studied, and the effects of different parameters on the adsorption characteristics
were investigated. The adsorption equilibrium data were well explained by the Langmuir
isotherm model. The sorption kinetics was tested with pseudo-first-order and pseudo-second-order
reaction and the rate constants of kinetic models were calculated. Results indicate that Cd2+ uptake
process followed the pseudo-second-order rate expression. Furthermore, thermodynamic studies
specify that adsorption was spontaneous and endothermic. The adsorption mechanism onto MNC
was controlled by electrostatic attraction between MNC and Cd2+. Excellent adsorption capacity with
other advantages such as reusability, easy separation, and environment-friendly composition make
them suitable adsorbents for removal of heavy metal ions from environmental and industrial wastes.
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