Improved Solid-Phase Synthesis of Phosphorylated Cellulose Microsphere Adsorbents for Highly Effective Pb2+ Removal from Water: Batch and Fixed-Bed Column Performance and Adsorption Mechanism

Abstract

A highly effective adsorbent with phosphate groups bound to cellulose microspheres was designed by an improved solid-phase modification method to adsorb lead ions from water by a batch and fixed-bed column method. The phosphorylated cellulose microsphere adsorbents were prepared through esterification by which phosphate groups were introduced to the interface of regenerated cellulose microspheres which were previously prepared through a sol–gel transition process from a simple cellulose solution. Their morphological, structural, and physicochemical properties were characterized by SEM, FTIR, XRD, and DSC, etc. Furthermore, EDX and XPS were used to confirm the chemical modification process and to investigate their phosphate adsorption mechanism. In the batch adsorption experiments, the equilibrium time and adsorption capacity were determined by both equilibrium and kinetic adsorption experiments, which were also conducted to investigate the adsorption mechanism. In the dynamic adsorption experiments, multi...