pH、富里酸和温度对铀酰在ZrP_2O_7上的吸附影响  

Effect of pH,fulvic acid and temperature on the sorption of uranyl on ZrP_2O_7

作　　者：钱丽娟[1] 胡佩卓[1] 蒋正江[1] 耿艳霞[1] 吴王锁[1] 

机构地区：[1]兰州大学核科学与技术学院,兰州730000

出　　处：《中国科学：化学》2010年第11期1712-1720,共9页SCIENTIA SINICA Chimica

基　　金：国家自然科学基金(20871062;J0630962)资助

摘　　要：采用质量滴定法和静态法分别研究了ZrP2O7的零电荷点(pHPZC)和铀酰离子在ZrP2O7上的吸附及解吸行为.铀酰离子在ZrP2O7上的吸附受体系pH、固液比、电解质种类及富里酸(FA)强烈影响,离子强度对铀酰离子在ZrP2O7上吸附的影响较小;随着固液比(m/V)和pH增大,吸附边界向左偏移;磷酸根与硫酸根对吸附有相反的影响;在低pH下,富里酸(FA)促进铀酰离子在ZrP2O7上吸附;柠檬酸根对吸附有非常大的影响;温度升高有利于吸附.采用Langmuir和Freundlich模型对吸附等温线进行拟合研究,表明Freundlich模型可以更好地拟合铀酰离子在ZrP2O7上的吸附.通过对热力学数据如(△H0,△S0和△G0)的计算可知吸附过程是自发和吸热过程.铀酰离子在ZrP2O7上吸附为不可逆吸附.The sorption of UO 2 2＋ onto ZrP2O7 was studied using the batch technique and the point of zero charge of ZrP2O7 was obtained through mass titration.The results indicated that sorption of UO 2 2＋ onto ZrP2O7 was strongly affected by pH,solid-to-liquid ratio（m/V） ,the species of electrolyte in solution and fulvic acid（FA） but was insensitive to ionic strength.The sorption of UO 2 2＋ increased with increasing pH and m/V.The presence of FA enhanced UO 2 2＋ sorption onto ZrP2O7 at low pH.The presence of phosphate or sulfate caused opposite effects on the sorption of UO 2 2＋ onto ZrP2O7.Addition of citrate also significantly affected UO 2 2＋ sorption.The sorption of UO 2 2＋ increased as the temperature of the system increased.The Langmuir and Freundlich models were used to simulate the sorption isotherms of UO2 2＋ onto ZrP2O7 at different temperatures.The results indicated that the Freundlich model described UO 22 ＋ sorption better than the Langmuir model.Thermodynamic parameters for the sorption process were calculated from the temperature dependent sorption isotherms.The results suggested that the sorption process of UO2 2＋ onto ZrP2O7 was spontaneous and endothermic.The desorption process of UO 2 2＋ from ZrP2O7 was also investigated and it was found that sorption onto ZrP2O7 was irreversible.

关 键 词：ZrP2O7 铀 吸附 解吸 热力学 

分 类 号：O647.3[理学—物理化学]