Adsorption of copper using macroporous phosphonic acid resin
摘要
The adsorption behavior and mechanism of a novel chelate resin, macroporous phosphonic acid resin(PAR) for Cu(Ⅱ) were investigated. The statically saturated Cu(Ⅱ) adsorption capacity is 168 mg/g resin at 298K in HAc-NaAc medium. The Cu(Ⅱ) adsorbed on PAR can be eluted by 1.03.0 mol/L HCl and the elution percentage reaches 100%. The resin can be regenerated and reused without apparent decrease in adsorption capacity. The apparent adsorption rate constant is (k=1.64×10~(-4) s~(-1)) at 298K. The adsorption behavior of PAR for (Cu(Ⅱ)) obeys the Freundlich isotherm. The thermodynamic adsorption parameters, enthalpy change ΔH, free energy change ΔG and entropy change ΔS of PAR for Cu(Ⅱ) are 11.8 kJ/mol, -2.0 kJ/mol and (46.4 J·mol~(-1)·K~(-1)) respectively. The apparent activation energy is E_a=8.0 kJ/mol. The molar coordination ratio of the functional group of PAR to Cu(Ⅱ) is about 2∶1. The adsorption mechanism of PAR for Cu(Ⅱ) was examined by chemical method and IR spectrometry.