文献类型： 外文期刊

作者： Wang Qiang ¹ ; Wei Shiqiang ¹ ; Huang Yuming ³ ; Zhang Jinzhong ¹ ;

作者机构： 1.Southwest Univ, Coll Resources & Environm, Chongqing 400716, Peoples R China

2.Chongqing Key Lab Agr Resources & Environm, Chongqing 400716, Peoples R China

3.Southwest Univ, Coll Chem & Chem Engn, Chongqing 400715, Peoples R China

关键词： adsorption and desorption characteristics;Al~(3+);humic acid

期刊名称：JOURNAL OF ENVIRONMENTAL SCIENCES （ 影响因子：5.9； 五年影响因子：5.6 ）

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收录情况： SCI

摘要： The adsorption and desorption characteristics of Al~(3+)to/from humic acids at different pH,ionic strength,and temperature were studied by the C-25 glucosan-gel chromatography method.The results showed that the maximum adsorption amount(Q_(max))and adsorption constant(k)increased,whereas,the absolute value of standard thermodynamic molar free energy change(DELTA G_m~0)decreased with the increase of pH at constant ionic strength and temperature.With ionic strength increasing from 0 to 0.15 mol/L,Q_(max)and k increased and the absolute value of DELTA G_m~0 decreased at constant pH and temperature.High temperature was unfavorable for the adsorption reaction,as indicated by the dramatic decrease of Q_(max)and the absolute value of DELTA G_m~0 with an increase in temperature.The standard thermodynamic molar free energy change(DELTA G_m~0)and the standard thermodynamic enthalpy change(DELTA G_m~0)of the adsorption reaction were both negative,suggesting that adsorption reaction was spontaneous and exothermic.The desorption rate of HA-Al~(3+)complex accelerated with the decrease of pH,and a significant linear relationship could be obtained between pH and the desorption rates of Al~(3+)from humic acids.These results demonstrated that the Al~(3+)adsorption reaction was a"biphase"reaction,and adsorption occurred at both the interior and exterior adsorption sites of humic acids.