Background: Cadmium, as a heavy metal, has received considerable attention due to its high toxicity, causing excessive damage to health and the biomagnification effects on ecology. In present study, a facile and economic approach has been described for preparing a novel magnetic EDTA/Chitosan/TiO₂ (MECT) nanocomposite to remove a wide range of pollutants, especially Cd(ІІ) ions, from aqueous solution.
Methods: In this method, not only EDTA has a cheap and environmentally friendly cross-linker function, embeds Fe₃O₄ nanoparticles in chitosan surface, but also participates in the chelating process of metal ions, caused by functional groups. The morphology, structure, and property of the MECT were characterized by FE-SEM, EDX, and XRD techniques and the effect of different parameters including pH, contact time, and initial cadmium concentration were evaluated.
Results: The results represented that MECT nanoparticles with an average diameter less than 40 nm had the best performance in adsorption of Cd(II) at optimum pH values of 5-6 and contact time of 120 min. Moreover, Langmuir adsorption isotherm is the best fit for the experimental data, in which maximum capacity of Cd(II) adsorption has been achieved 211.416 mg g^-1. Finally, reusability of the nanocomposite was measured using Na₂EDTA as an elution agent and regeneration efficiency of MECT was observed more than 90% in five successive sorption-desorption cycles.
Conclusions: Thus, magnetic MECT nanocomposite as an environmentally friendly, economical, and recyclable adsorbent has a great potential to develop the industry of water and wastewater treatment.