Efficient removal of Cu(II) and Pb(II) heavy metal ions from water samples using 2,4-dinitrophenylhydrazine loaded sodium dodecyl sulfate-coated magnetite nanoparticles

This study reports on synthesis of a new nanoadsorbent for efficient Cu(II) and Pb(II) ions removal from water samples. In this regard, magnetite nanoparticles have been modified with 2,4-dinitrophenylhydrazine. The synthesized adsorbent has been fully characterized using scanning electron microscope, X-ray diffractometer, Fourier transform infrared spectrometer, and Brunauer, Emmett, and Teller measurements. The metal ions adsorption process has been thoroughly studied from both kinetic and equilibrium points of views. The adsorption isotherms were analyzed using five different isotherm models. It was found that the Sips isotherm showed better correlation with the experimental data than other isotherms, and the synthesized nanoadsorbent presents adsorption capacities for removal of Pb(II) and Cu(II) as high as 484.7 mg g⁻¹ and 570.0 mg g⁻¹, respectively. The adsorption kinetics was tested for the pseudo-first order and pseudo-second order kinetic models at different experimental conditions. The kinetic data showed that the process is very fast and the adsorption process follows pseudo-second order kinetic models for modified magnetite adsorbents. The results suggest that the new nanoadsorbent is favorable and useful for the removal of the investigated metal ions under the optimized condition (pH: 6.0, adsorbent dosage: 0.02 g, agitation time: 45 min), and the high adsorption capacity makes it promising candidate material for metal ions removal from water samples.