Fe3O4 encapsulated by sodium polyacrylate (CPAANa@Fe3O4)
was prepared via dispersed solution polymerization followed by Ca2+ surface-crosslinking and characterized by techniques of XRD
FT-IR
SEM and TGA. Static adsorption of Pb2+ and Cd2+ ions to the polymer in aqueous solutions was investigated by varying solution pH
polymer adsorbent dosage
and initial concentration of heavy metal ions. The CPAANa@Fe3O4 magnetic crosslinking polymer showed good adsorption performance in solutions with pH in the range of 2-6. The maximum adsorptions for Pb2+ and Cd2+ were observed at adsorbent dosage of 1.0 and 1.6 g·L-1 for initial Pb2+ concentration of 200 mg·L-1 and initial Cd2+ concentration of 100 mg·L-1
respectively
such that the residual Pb2+ concentration could meet the standard for discharge (GB 8978-1996). The adsorption kinetics of both Pb2+ and Cd2+ on CPAANa@Fe3O4 polymer followed pseudo-second order model and their adsorption isotherms obeyed the Langmuir model. Maximum adsorption capacities of the polymer for Pb2+ and Cd2+ were 454.55 and 275.48 mg·g-1
respectively. The CPAANa@Fe3O4 polymer effectively removed Pb2+ and Cd2+ from complex electrolytic pulp wastewater
indicating its potential application advantages as an efficient adsorbent.