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

In the current work, we developed glutaraldehyde (GA) cross linked composite film containing poly (vinyl alcohol) (PVA) as a matrix and modified alpha-manganese dioxide (alpha-MnO2) nanorods with 3-aminopropyltriethoxysilane (APES) (alpha-MnO2-APES), as a nanofiller. Consequently, we investigated the Pb2+ adsorption process onto the PVA-GA/alpha-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 alpha-MnO2 without surface modification as a control substance. The results showed that the PVA-GA/alpha-MnO2-APES composite has a promising potential for adsorption of Pb2+ from the water media. The adsorptive behavior of the PVA-GA/alpha-MnO2-APES composite matched with the linear pseudo-secondorder kinetic and linear Freundlich isotherm models. The thermodynamic parameters (Delta G degrees and Delta H degrees) 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. (C) 2019 Elsevier Ltd. All rights reserved.