Amine-crosslinked Shaddock Peel embedded with hydrous zirconium oxide nano-particles for selective phosphate removal in competitive condition

In this paper, we prepared a novel biomass-based adsorbent, amine-crosslinked Shaddock Peel embedded with nano hydrous zirconium oxide (ACSP-HZO), to capture the phosphate ions in competitive adsorption systems. The ACSP-HZO was characterized by SEM, EDS, FTIR, XRD, TEM, XPS and Zeta potential analysis. Zeta potential indicated that the pure HZO nanoparticles were negatively charged. Element mapping showed that Zr distribution is closely related to P distribution, which indicated that the phosphate adsorption was dominated by the negatively charged HZO nanoparticles in ACSP-HZO. Results indicated that the ACSP-HZO exerted higher absorption capacity for phosphate than amine-crosslinked, Shaddock Peel (ACSP). The maximum adsorption capacity of phosphate declined as temperature arose, which indicated the exothermal nature of phosphate adsorption by ACSP-HZO. Results in kinetics study indicated that the adsorption equilibrium data was fitted better with pseudo-second-order rate model. Phosphate adsorption by ACSP-HZO decreased as the increase of humic acid (HA), but effect of HA on phosphate adsorption by ACSP was negligible. In desorption experiment, spent ACSP-HZO still showed great capacity for phosphate after two cycles of adsorption-desorption. (C) 2017 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.