( 1. 麗水學(xué)院 化學(xué)系， 麗水 323000；
2. 浙江工商大學(xué) 化學(xué)系， 杭州 310035)
摘 要: 研究了用亞胺基二乙酸樹脂(D401)吸附鎘離子的過程。 結(jié)果表明， 在pH=5.73時樹脂對鎘的吸附效果最佳， 測得樹脂的靜態(tài)飽和吸附容量為363 mg·g-1； 用0.5 mol/L HCl作解吸劑， 解吸率為100%， 表觀吸附速率常數(shù)k298=2.05×10-5 s-1， 表觀吸附活化能Ea=18.0 kJ/mol， 等溫吸附服從Freundlich經(jīng)驗(yàn)式； 吸附熱力學(xué)參數(shù)ΔH=3.08 kJ/mol， ΔS=35.9 J/(mol·K)， ΔG=-7.62 kJ/mol， 樹脂功能基與鎘離子的配位摩爾比為1∶1。 用化學(xué)和紅外光譜等方法討論了吸附機(jī)理。
關(guān)鍵字: 亞胺基二乙酸樹脂； 鎘； 動力學(xué)； 熱力學(xué)； 吸附； 機(jī)理
（ 1. Department of Chemistry, Lishui University, Lishui 323000, China;
2. Department of Chemistry, Zhejiang Gongshang University,
Hangzhou 310035, China）
Abstract: The sorption of Cd(Ⅱ) with iminodiacetic acid resin (D401) was investigated. The results show that D401 has a good sorption ability for Cd(Ⅱ) in the HAc-NaAc medium at pH=5.73. The statically saturated sorption capacity of resin is 363 mg/g and 0.5 mol/L HCl can be used as an eluant; the elution percentage is 100%, the sorption rate constant is k298=2.05×10-5 s-1, and the apparent sorption activation energy of D401 for Cd(Ⅱ) is 18.0 kJ/mol. The sorption behavior of D401 for Cd(Ⅱ) obeys the Freundlich isotherm. The sorption thermodynamic parameters of D401 for Cd(Ⅱ) are: enthalpy change ΔH=3.08 kJ/mol, free energy change ΔG =-7.62 kJ/mol, entropy change ΔS=35.9 J/(mol·K), respectively. The coordination molar ratio of the functional group of D401 to Cd(Ⅱ) is 1∶1. The sorption mechanism of D401 for Cd(Ⅱ)was confirmed by chemical analysis and IR spectrometry.
Key words: iminodiacetic acid resin; cadmium; kinetics; thermodynamics; sorption; mechanism
