Cross-linked poly (vinyl alcohol)/modified α-manganese dioxide composite as an innovative adsorbent for lead (II) ions

Abstract

In the current work, we developed glutaraldehyde (GA)-cross-linked composite film containing poly (vinyl alcohol) (PVA) as a matrix and modified α-manganese dioxide (α-MnO₂) nanorods with 3-aminopropyltriethoxysilane (APES) (α-MnO₂-APES), as a nanofiller. Consequently, we investigated the Pb²⁺ adsorption process onto the PVA-GA/α-MnO₂-APES composite. In order to study the effect of APES on the adsorption performance of the composite, we used GA-cross-linked composite containing PVA and α-MnO₂ without surface modification as a control substance. The results showed that the PVA-GA/α-MnO₂-APES composite has a promising potential for adsorption of Pb²⁺ from the water media. The adsorptive behavior of the PVA-GA/α-MnO₂-APES composite matched with the linear pseudo-second-order kinetic and linear Freundlich isotherm models. The thermodynamic parameters (ΔG° and ΔH°) indicated the spontaneous and endothermic nature of Pb²⁺ adsorption onto the aforementioned composite, accompanied by physical interactions. Furthermore, the obtained composite owing to its easy preparation and separation would be a cost-effective sorbent.