Abstract
Composite particles of superparamagnetic nanoparticles coated with silica and chelate resin, we call superparamagnetic chelate resin (SPMCR) particles, were synthesized by a combined method of aerosol and liquid process for removing metal ions from wastewater by adsorption. First, Fe3O4 nanoparticles were prepared by a co-precipitation method and were embedded in silica particles by an alkaline hydrolysis of tetraethylorthosilicate. The Fe3O4 nanoparticles embedded in silica particles (Fe3O4@SiO2 nanoparticles) showed a magnetic property similar to superparamagnetic and were hardly dissolved in 2M HCl aqueous solution. Then the SPMCR particles were prepared by spraying the suspension of Fe3O4@SiO2 nanoparticles and chelate resin particles. The resultant particles by this method were the mixture of SPMCR particles and Fe3O4@SiO2 nanoparticles. They adsorbed 0.89 mmol g-1 of Cu2+ but 0.61 mmol g-1 was recovered by the desorption with water. Both the adsorbed and the desorbed masses of Cu2+ were reduced by 22~25 % after five repetitions of adsorption and desorption.
