A facile syntheses of two engineered poly(vinyl alcohol) macroporous hydrogel beads for the application of Cu(II) and Pb(II) removal: batch and fixed bed column

In this work, two novel macroporous hydrogel beads (PVA/GO–N and PVA/CS) were prepared to remove Cu²⁺ and Pb²⁺ ions in the solution. The maximum Cu²⁺ sorption capacities on PVA/GO–N and PVA/CS beads were 96.22 and 74.66 mg g⁻¹, while the counterpart sorption capacities of Pb(II) were 278.16 and 144.53 mg g⁻¹, respectively. Isotherm, kinetics and XPS analysis investigation indicated that the sorption processes were controlled by multiple mechanisms. The Cu(II) and Pb(II) removal rates were influenced by the changes of pH, initial dosage, ionic strength, chelator and co-existed ions. The packed-bed sorption column experiments were also carried out to investigate the operating parameters and the potential of the two adsorbents in large scale adsorption systems in practical use. The kinetic model, Thomas equation, was applied to predict dynamic behavior of the fixed bed column for a successful design of a sorption column. (paper)