Antibacterial property and biocompatibility of Chitosan/Poly(vinyl alcohol)/ZnO (CS/PVA/ZnO) beads as an efficient adsorbent for Cu(II) removal from aqueous solution

Abstract

The feasibility of using chitosan/Poly(vinyl alcohol)/ZnO beads (CS/PVA/ZnO) as an adsorbent for removal of Cu(II) ions from aqueous solutions was studied in a batch method. The developed adsorbent material was characterized by XRD, FTIR, SEM and TEM analysis. Pure ZnO shows the characteristic peaks at (100), (002), (101), (102), (110), (103), (200) and (112) that were in good agreement with wurtzite ore having hexagonal lattice structure. Antibacterial properties and biocompatibility of the CS/PVA/ZnO was tested. CS/PVA/ZnO showed strong antibacterial property as well as it was biocompatible. The antibacterial activity of CS/PVA/ZnO against Escherichia coli, and Staphylococcus aureus were evaluated with the zone of inhibition method. The effect of various process variables such as solution pH, adsorbent dose, contact time, initial metal ion concentration, and temperature was investigated. The adsorption kinetic data was fitted well with the pseudo-second-order model. Langmuir and Freundlich isotherm models were used to analyze the equilibrium data. Langmuir model showed better correlation to the experimental data compared to Freundlich model. Different thermodynamic parameters namely, Gibbs free energy, enthalpy and entropy changes were also evaluated from the temperature dependence, and the results suggested that the sorption of Cu(II) onto CS/PVA/ZnO is spontaneous and endothermic in nature. The maximum adsorption capacity of CS/PVA/ZnO was found to be 90.90 at pH 4.5 and indicated that developed material could be effectively utilized for the removal of Cu(II) ions from aqueous environment.