金属有机框架MIL-101(Fe)对水中微囊藻毒素-LR的吸附

通过溶剂热法制备了性质稳定的金属有机框架材料MIL-101(Fe),并用于吸附去除水中的微囊藻毒素-LR。采用电子显微镜、傅立叶变换红外光谱(FT-IR)、Zeta电位和N_2吸附-脱附等方法对制备的纳米材料进行了表征。MIL-101(Fe)具有多孔结构和较高的比表面积(375.2 m~2/g),尺寸约为500 nm。考察了pH值、离子强度、温度、吸附时间、浓度等参数对吸附剂吸附能力的影响。结果表明,静电作用和配位作用是主要的作用机理。MIL-101(Fe)对微囊藻毒素-LR的吸附速度很快(20 min内达到吸附平衡),吸附过程符合准二级动力学模型;MIL-101(Fe)对微囊藻毒素-LR表现出良好的吸附性能,其最大吸附量为256.4 mg/g。溶液中存在的腐植酸对MIL-101(Fe)的吸附性能产生一定的影响。受腐殖酸、盐类的影响,相同条件下MIL-101(Fe)对江水中微囊藻毒素-LR的吸附性能有所下降,但仍可达到68.1 mg/g。因此,该方法简便、高效,适用于快速除去污染水体中的微囊藻毒素-LR。

Adsorption of Microcystin-LR in Water with Metal-Organic Framework MIL-101(Fe)

A water stable metal-organic framework MIL-101(Fe) was synthesized by the solvothermal method,which could be employed as a high efficiency adsorbent for removal of microcystin-LR in aqueous solution.The as prepared nanomaterial was characterized by Electron microscopy,Fourier transformed infrared(FT-IR),zeta potential and N2 adsorption desorption measurement,respectively.The MIL-101(Fe) had a porous structure and a high specific surface area(375.2 m2/g) with an average size about 500 nm.Experimental parameters affecting the adsorption capacity,including pH,ionic strength and temperature,adsorption time and concentration were particularly optimized.Results indicated that the adsorption mechanisms could be expressed by the electrostatic attraction and coordination interaction between MIL-101(Fe) and microcystin-LR.The adsorption of microcystin-LR on MIL-101(Fe) was very fast as an adsorption equilibrium was obtained within 20 min,which agreed well with the pseudo second order model.Moreover,the porous MIL-101(Fe) exhibited an excellent adsorption property for microcystin-LR,with a maximum adsorption capacity of 256.4 mg/g.The humic acid in the solution could affect the adsorption capacity of MIL-101(Fe).Under the same conditions,the adsorption capacity for microcystin-LR in river water decreased due to the influence of humic acid and salts in real water samples.Nevertherless,the adsorption capacity still reached to 68.1 mg/g.Thus,the method is efficient and convenient,and is suitable for the rapid removal of microcystin-LR in contaminated water.