Dynamic Adsorption and Desorption Behaviors of Cu(II), Ag(I), and Au(III) on Silica Gel Microspheres Encapsulated by Salicylic Acid-Functionalized Polystyrene.

Composite material silica gel microspheres encapsulated by salicylic acid functionalized polystyrene(SG-PS-azo-SA) have been synthesized, and the dynamic adsorption and desorption properties of this silica gel matrix inorganic-organic composite material for Cu(II), Ag(I), and Au(III) have been investigated. The results displayed that SG-PS-azo-SA had excellent adsorption for Cu(II), and the film diffusion dominated the adsorption process of SG-PS-azo-SA for Cu(II), Ag(I), and Au(III). These metal ions could be desorbed with the eluent solution of 2.5 mol/L HCl, 3% thiourea in 0.5 mol/L HCl, and 0.5% thiourea in 1 mol/L HCl, respectively. When the elution was carried out for 30 min, 30 min, and 132 min, the desorption ratio ω could reach 91.1%, 99.4%, and 60.84%, respectively. Thus, silica gel encapsulated by polystyrene coupled with salicylic acid (SG-PS-azo-SA) is favorable and useful for the removal of metal ions Cu(II), Ag(I), and Au(III), and the high adsorption capacity make it a promising candidate material for the metal ions removal. [ABSTRACT FROM AUTHOR]