Preparation of Thiourea Functionalized Polyvinyl Alcohol-Coated Magnetic Nanoparticles and Their Application in Pb~(2+) Ions Adsorption

摘要

We have prepared a novel kind of magnetic nanoparticle with high adsorption capacity and good selectivity for Pb~(2+) ions by modifying the magnetic nanoparticles with polyvinyl alcohol (PVA) and thiourea. The resultant magnetic nanoparticles were used to adsorb Pb~(2+) ions from aqueous solution. The influence of the solution pH, the adsorption time, the adsorption temperature, coexisting ions, and the initial concentration of Pb~(2+) ions on the adsorption of Pb~(2+) ions were investigated. The results indicated that Pb~(2+) ions adsorption was an endothermic reaction, and adsorption equilibrium was achieved within 30 min. The optimal pH for the adsorption of Pb~(2+) ions was pH 5.5, and the maximum adsorption capacity of Pb~(2+) ions was found to be 220 mg/g. Moreover, the coexisting cations such as Ca~(2+), Co~(2+), and Ni~(2+) had little effect on adsorption of Pb~(2+) ions. The regeneration studies showed that thiourea functionalized PVA-coated magnetic nanoparticles could be reused for the adsorption of Pb~(2+) ions from aqueous solutions over five cycles without remarkable change in the adsorption capacity.