Journal of Hazardous Materials, Vol.337, 178-188, 2017
Preparation and characterization of a novel macroporous silica-bipyridine asymmetric multidentate functional adsorbent and its application for heavy metal palladium removal
The effective removal of heavy metal Pd-107(II) from highly active liquid waste (HLW) is very valuable for reducing its hazardous and risk to public health and environment. For this purpose, a novel silica-bipyridine multidentate functional adsorbent was synthesized by vacuum infusing a new asymmetric N-donor ligand CA-MTBP (bipyridine derivative) into the macroporous SiO2-P support. SEM, N-2 adsorption-desorption isotherms, TGA, XRD, FT-IR, Si-29 solid-state NMR and XPS spectroscopy were utilized to systematically characterize the physicochemical properties of the adsorbent. The characterization results indicated that CA-MTBP was successfully immobilized onto the pores of SiO2-P by intermolecular interaction. Strong hydrogen-bonding interactions identified by single crystal structure of the ligand and Si-29 NMR may play a key role in achieving this immobilization. TGA and TOC studies showed that CA-MTBP/SiO2-P had excellent thermal stability and highly HNO3 resistance. EDS and XPS investigations provided directly evidences for Pd(II) being selectively adsorbed onto the adsorbent. The adsorbent had excellent adsorption capability, fast adsorption kinetics and high selectivity for Pd(II) over other typical tested metals in HNO3 media. (C) 2017 Published by Elsevier B.V.