羧甲基葡甘聚糖铝凝胶球氟离子吸附材料及性能

Fluorine Ion Adsorption Material of Carboxyl Methyl Konjac Glucomannan Gel Microspheres and Performances

用Al2(SO4)3溶液与羧甲基葡甘聚糖反应制得新型吸附材料———羧甲基葡甘聚糖铝凝胶球,用扫描电镜表征了微球结构,测定了微球机械强度。研究了微球对氟离子的吸附性能,分别考察了铝离子浓度、羧甲基葡甘聚糖浓度、吸附时间、pH值、氟离子浓度和温度等因素对吸附的影响,同时用红外光谱初步表征了微球的结构。结果表明,293 K时,微球对氟离子的吸附在6 h达平衡,当羧甲基葡甘聚糖质量浓度为1.2%,铝离子质量浓度为2.0%,氟离子浓度为90.50 mg/L时,吸附量为47.02 mg/g。根据不同温度下铝凝胶球吸附氟离子的等温线,计算了吸附过程的热力学参数,同时用Freundlich方程对实验数据进行了拟合,发现该方程适用于所研究的吸附体系。该体系为自发放热过程,体系熵减少,降温有利于吸附。

The aluminum carboxyl methyl konjac glucomannan gel microspheres（CMKGM-Al） were prepared by crosslinking aluminum ion（Al3＋） and carboxyl methyl konjac glucomannan（CMKGM）.The adsorption capacity of CMKGM-Al for fluoride ion was studied.Several parameters including adsorption time,the concentration of CMKGM,the mass ratio of Al3＋,microsphere size,pH,temperature,and the concentration of F-,which effect the adsorption performance,were investigated.The compound of CMKGM-Al /F-was characterized by IR spectrometry.The results showed that the adsorption equilibrium could be established about 6 hours when the temperature was 293 K.The adsorption capacity reached 47.02 mg/g,while the concentration of CMKGM was 1.2%,the mass ratio of Al3＋ was 2.0% and the concentration of F-was 90.5 mg/L.The thermodynamic parameters of adsorption process were calculated according to isotherms at different temperatures.The experimental data were fitted using the Freundlich equation,and it was found that the equation was applicable to the studied adsorption system.The system was a spontaneous exothermic process and the entropy of the system decreased.The low temperature was favorable for adsorption.