Recovery of Cu(II) and Cd(II) by a chelating resin containing aspartate groups.
A chelating resin, crosslinked poly(glycidyl methacrylate-aspartic acid) (PASP), was synthesized by anchoring sodium aspartate to crosslinked poly(glycidyl methacrylate) for the recovery of Cu2+ and Cd2+ from aqueous solutions. The resin was characterized by Fourier transform infrared spectroscopy, scanning electron microscope and mass balance. In non-competitive conditions, the adsorptions tended toward equilibrium at 60 min and the equilibrium adsorption capacities were 1.40 and 1.28 mmol/gPASP for Cu2+ and Cd2+, respectively. The adsorption isothermals of the metal ions by PASP followed the Freundlich isotherm. Adsorption of Cu2+ was affected slightly in the presence of NaNO3 (0-0.3M) but the uptake of Cd2+ decreased significantly in the same condition. Except pH> or =4.0, the adsorption capacity of each metal ion decreased with lowering of solution pH. The reusability of PASP in adsorptions was investigated for five successive adsorption-desorption operations. When the pH of Cu2+/Cd2+ mixture was 2 or 2.5, the competitive adsorption tests confirmed this resin had good adsorption selectivity for Cu2+ with the coexistence of Cd2+.
Chen
Chuh-Yean
CY
Department of Chemical and Materials Engineering, Southern Taiwan University, 710 Yung-Kang City, Tainan County, Taiwan. yean@mail.stut.edu.tw <yean@mail.stut.edu.tw>
Lin
Mao-Syong
MS
Hsu
Kun-Rong
KR
D000327:Adsorption; D001224:Aspartic Acid / Q000737:chemistry*; D002104:Cadmium / Q000302:isolation & purification*; D002614:Chelating Agents / Q000737:chemistry*; D003300:Copper / Q000302:isolation & purification*; D008855:Microscopy, Electron, Scanning