摘要
寻找具有高效、高吸附量、高选择性的吸附剂处理放射性的含铀废水,对环境保护具有现实意义.通过溶剂热法合成两种金属有机框架材料MIL-125和NH2-MIL-125,并用X-射线衍射仪(XRD)、扫描电镜(SEM)、傅里叶变换红外光谱仪(FT-IR)、热重分析仪(TGA/DSC)等仪器对两种材料的结构和形貌分别进行表征,探究不同的初始pH、初始铀浓度、吸附时间等条件下两种材料分别对UO2^2+吸附性能的影响.结果表明:本实验成功合成了MIL-125和NH2-MIL-125两种材料;当初始pH分别为5和8时,MIL-125和NH2-MIL-125材料对UO2^2+的吸附效果最好.通过Langmuir和Freundlich方程进行热力学拟合可知,两种材料的吸附过程更符合Langmuir方程,在25℃时MIL-125、NH2-MIL-125对UO2^2+的最大吸附量分别为264.4 mg·g^-1和327.3 mg·g^-1,最佳吸附时间分别为480 min和70 min.
It has realistic significance to environmental protection,finding the efficient,high-absorption and high-selectivity adsorbents to deal with uranium-containing wastewater.Herein we report two Mental-Organic Framework materials MIL-125 and NH2-MIL-125 synthesized by solvothermal method.The materials have been characterized by using X-ray diffraction(XRD),scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FT-IR)and thermogravimetry analysis/differential scanning calorimetry(TGA/DSC).The adsorption performance of the adsorbents for UO2^2+were investigated at different initial pH,uranium concentration,and contact time.The results showed that MIL-125 and NH2-MIL-125 were synthesized successfully,and the synthesized powders exhibited the strongest adsorption capacity for UO2^2+when the initial pH was 5 and 8,respectively.A comparison of the Langmuir,Freundlich equations to describe UO22+adsorption properties of the two materials showed that the adsorption processes were more consistent with the Langmuir equation.At 25℃,the maximum adsorption capacity of MIL-125 and NH2-MIL-125 were 264.4 mg·g^-1 and 327.3 mg·g^-1,and the optimal adsorption time were 480 min and 70 min.
作者
张莉莉
许成
陈元涛
张炜
ZHANG Lili;XU Cheng;CHEN Yuantao;ZHANG Wei(School of Chemistry and Chemical Engineering,Qinghai Normal University,Xining 810008)
出处
《环境科学学报》
CAS
CSCD
北大核心
2020年第6期2055-2065,共11页
Acta Scientiae Circumstantiae
基金
国家自然科学基金(No.21667024)。
