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

Abstract

Background: The effluent release containing heavy metals as Cd (II) ions has 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 affection of adsorbent amount, pH, temperature, equilibrium time on its sorption with Gr2Ap adsorbent was studied and 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, to inspect the basic process of the metal sorption mechanism pseudo-first and second-order kinetic, and Roginsky-Zeldovich types were 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, that the Gr2Ap adsorbent exhibits the highest ability to adsorb Cd (II) ions (22.54 mg/g) at pH=6. The pseudo-second-order pattern of Cd (II) adsorption fits 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 was shown an efficient, easy, inexpensive, and selectable method for evaluating the Cd (II) ions in several samples of water and wastewater.