Adsorption of Er(Ⅲ) and Its Mechanism on Diglycolamidic Acid Resin
来源期刊:JOURNAL OF RARE EARTHS2002年第5期
论文作者:熊春华 沈秋仙
Key words:rare earths; diglycolamidic acid resin; erbium; sorption mechanism;
Abstract: The adsorption behavior and mechanism of a novel chelate resin, diglycolamidic acid resin (DAAR) for Er(Ⅲ) were investigated. The optima adsorption condition of DAAR for Er(Ⅲ) is pH 6.20 in HAc-NaAc medium. The statically saturated adsorption capacity is 189 mg*g-1 resin at 298 K. The Er (Ⅲ) adsorbed on DAAR can be eluted reaching 100% by 2 mol*L-1 HCl used as eluant. The resin can be regenerated and reused without apparent decreasing of adsorption capacity. The apparent adsorption rate constant is k298=1.94×10-5 s-1. The apparent activation energy is 24.7 kJ*mol-1. The adsorption behavior of DAAR for Er(Ⅲ) obeys the Freundlich isotherm. The thermodynamic adsorption parameters, enthalpy change ΔH of DAAR for Er(Ⅲ) is 24.1 kJ*mol-1. The molar coordination ratio of the functional group of DAAR to Er (Ⅲ) is 3∶1. The adsorption mechanism of DAAR for Er (Ⅲ) was examined by using chemical method and IR spectrometry. The coordination compound is formed between oxygen atoms in the functional group of DAAR and Er(Ⅲ).
熊春华1,沈秋仙1
(1.Department of Chemistry, Lishui Teachers College, Lishui 323000, China)
Abstract:The adsorption behavior and mechanism of a novel chelate resin, diglycolamidic acid resin (DAAR) for Er(Ⅲ) were investigated. The optima adsorption condition of DAAR for Er(Ⅲ) is pH 6.20 in HAc-NaAc medium. The statically saturated adsorption capacity is 189 mg*g-1 resin at 298 K. The Er (Ⅲ) adsorbed on DAAR can be eluted reaching 100% by 2 mol*L-1 HCl used as eluant. The resin can be regenerated and reused without apparent decreasing of adsorption capacity. The apparent adsorption rate constant is k298=1.94×10-5 s-1. The apparent activation energy is 24.7 kJ*mol-1. The adsorption behavior of DAAR for Er(Ⅲ) obeys the Freundlich isotherm. The thermodynamic adsorption parameters, enthalpy change ΔH of DAAR for Er(Ⅲ) is 24.1 kJ*mol-1. The molar coordination ratio of the functional group of DAAR to Er (Ⅲ) is 3∶1. The adsorption mechanism of DAAR for Er (Ⅲ) was examined by using chemical method and IR spectrometry. The coordination compound is formed between oxygen atoms in the functional group of DAAR and Er(Ⅲ).
Key words:rare earths; diglycolamidic acid resin; erbium; sorption mechanism;
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