Removal of Cd (II) Ions from Water Solutions Using Dispersive Solid-Phase Extraction Method with 2-aminopyridine/graphene Oxide Nano-Plates

Background: The effluent release containing heavy metals, such as Cd (II) ions, poses drastic risks to both the natural environment and human health. In this research, a novel nano sorbent from the pyridine derivative was prepared for dispersive solid-phase extraction of Cd (II) ions. Methods: Graphene oxide (GrO) was chemically modified by a 2-aminopyridine group (2Ap) through a multistep procedure. The effect of adsorbent amount, pH, temperature, and equilibrium time on sorption of the Gr2Ap adsorbent was studied; Gr2Ap adsorbent displayed a high ability to adsorb Cd (II) at pH = 6. Furthermore, to inquire about the adsorption isotherms of metal ions sorption mechanism, the model of Freundlich and Langmuir was fitted to empirical isotherm data. Besides, in the inspection of the basic process of the metal sorption mechanism, pseudo-first and second-order kinetics and Roginsky-Zeldovich types were found to be compatible with adsorption kinetic results. Results: The concentration factor and limit of detection for Cd (II) were 12.5 and 1.84 μg/L, respectively. According to the value of the correlation coefficient factor, the Gr2Ap adsorbent exhibited the highest ability to adsorb Cd (II) ions (22.54 mg/g) at pH=6. The pseudo-second-order pattern of Cd (II) adsorption fit best with the kinetic result. Conclusion: The Gr2Ap exhibited a high potential for removing the heavy metal ions from aqueous samples. Besides, the current research showed the method to be efficient, easy, inexpensive, and apt for evaluating the Cd (II) ions in several samples of water and wastewater.