Studies on the uptake behavior of a magnetic Co3O4-containing resin for Ni(II), Cu(II) and Hg(II) from their aqueous solutions

A magnetic chelating resin was obtained from polymerization of glycidyl methacrylate in the presence of divinylbenzene as a crosslinker and finely divided magnetic particles of Co3O4. The resin obtained was investigated by means of XRD, IR, magnetic susceptibility and DTA/TGA thermal analysis. The measurements showed that the particles of Co3O4 became completely coated with a film of the resin. The embedded metal oxide particles impart magnetic properties to the resin in addition to increasing the chelating active sites on the surface. The resin obtained was modified with amine functionality and evaluated towards the uptake of Hg2+, Cu2+ and Ni2+ from their aqueous solutions. Various factors affecting the uptake behaviour such as contact time, pH and initial concentration of the metal ions were investigated. Uptake values of 2.10, 2.00 and 1.10 mmol/g were recorded for Hg2+, Cu2+ and Ni2+, respectively. The adsorption results were found to fit Langmuir model. The modified resin displays higher uptake capacity compared to the metal oxide-free resin. The loaded resin with metal ions was regenerated to efficiency of 97.5% using 1 M H2SO4.