Adsorptive removal of cadmium from aqueous solutions using NiFe2O4/hydroxyapatite/graphene quantum dots as a novel nano-adsorbent

Parya Kahrizi, Fatemeh S. Mohseni-Shahri, Farid Moeinpour
2018 Journal of Nanostructure in Chemistry  
In this study, NiFe 2 O 4 /hydroxyapatite/graphene quantum dots (NiFe 2 O 4 /HAP/GQDs) as nano-adsorbent to remove cadmium (Cd 2+ ) from aqueous solution were synthesized. This nano-adsorbent was depicted by some techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR). Adsorption studies were conducted to investigate the effect of contact time, pH, adsorbent dosage and initial
more » ... um ion concentration on removal efficiency. To determine the most fitting kinetic model, the suitability of pseudo-first-order and pseudo-second-order models was compared. The adsorption isotherm was described well by the Langmuir isotherm and maximum equilibrium uptake capacity (q e ) was 344.83 mg g −1 . Studies revealed that adsorption process is not a physical process and formation of complexes (bidentate and monodentate complexes) between-COO − and-OH functional groups on the surface of NiFe 2 O 4 /HAP/GQDs and Cd 2+ ions may occur. In addition, the adsorbent can simply be removed by an ordinary filtration process.
doi:10.1007/s40097-018-0284-3 fatcat:cmznjvrwgjb4hfia3uqvfmtsoy