Highly efficient removal of toxic As(V), Cd (II), and Pb(II) ions from water samples using MnFe2O4@SBA-15-(CH2)3-adenine as a recyclable bio-nanoadsorbent

Millions of people nowadays are exposed to highly toxic ions, including arsenic, cadmium, and lead, which all have detrimental effects on human health and cause irreparable damage to the nature and health of living species. It is, therefore, absolutely crucial to remove these toxic ions from ecosystems. Herein, a sponge-like bio-nanocomposite with a core-shell-shell structure consisting of magnetic MnFe2O4 nanoparticles (NPs) as core and mesoporous silica (SBA-15) functionalized with the nucleobase adenine (Ade) as a shell was synthesized to be applied for the adsorptive removal of toxic ions from aqueous media. The prepared material was characterized using various techniques, such as FTIR, XRD, TEM, VSM, and BET. Under optimum conditions, the MnFe2O4@[email protected](CH2)3-Ade removed As(V), Cd(II), and Pb(II) ions with greater than 96% efficiency. The kinetic and equilibrium data were satisfactorily described by the pseudo-second-order and the Redlich-Peterson models. The maximum adsorption capacities for As(V), Cd(II), and Pb(II) were calculated to be 21.99 mg g−1, 29.62 mg g−1, and 31.01 mg g−1, respectively. Also, the bio-nanocomposite showed ion removal efficiencies of over 95% during the seventh cycle of adsorption-desorption. Pb (II) ions had a stronger affinity for the active sites of the bio-nanoadsrobent when all of the studied systems (mono-, bi-, and multi-component) were compared. In addition, the practical application of the bio-nanocomposite for ion capture was evaluated in groundwater and industrial wastewater samples. Based on the findings of this study, the MnFe2O4@[email protected](CH2)3-Ade can be considered a promising adsorbent for the fast and efficient removal of heavy metals from water matrices.