Materials characterization and adsorption isotherm data

Nano-zirconia (ZO) was synthesized using a microwave assisted one pot precipitation route. Two biopolymers, chitosan (CTS) and carboxymethyl cellulose (CMC), were then combined with zirconia at different w/w ratios in order to identify the system with the most improved sorption properties towards Pb(II), Cd(II), As(V) and F-. The formulation with 30% w/w chitosan (ZO-CTS) was found to give enhanced uptake of F- and As(V). Improved sorption properties could not be observed for Pb(II) and Cd(II) in any of the ZO-polymer blends, with ZO being the most potent sorbent here. ZO and the lead system ZO-CTS were characterized in detail using Fourier transform infra-red spectroscopy, scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy (XPS). These confirmed the formation of a composite system comprising nanoparticles with 50 nm in size in which ZO was present in the amorphous form. Interactions between Zr and the amide and hydroxide groups of chitosan were suggest..., ,