钇锆双金属MOFs对有机膦阻垢剂HEDP的吸附研究

Adsorption of yttrium/zirconium bimetallic organic frameworks on organic phosphonate scale inhibitor HEDP

采用溶剂热法首次合成了新型钇锆双金属有机框架(YZr-MOF)吸附材料,并对其结构和表面性质进行了表征,研究了YZr-MOF对有机膦阻垢剂羟基亚乙基二膦酸(HEDP)的吸附行为和性质。实验结果表明,YZr-MOF呈现出大小均匀的球形颗粒结构,比表面积为912.862 m^(2)/g;在298 K时,YZr-MOF理论最大吸附量为66.293 mg/g(以P计)。吸附过程符合准二级动力学和Langmuir模型,吸附过程为吸热过程,温度升高有利于YZr-MOF吸附HEDP。在吸附实验中,YZr-MOF的最佳质量浓度为0.2 g/L;YZr-MOF在较宽的pH范围内有着良好的稳定性,并且经过6次循环后,仍保持显著的吸附率。结合相关实验和FTIR、XPS的表征结果表明,静电作用和配体交换为主要吸附机理。

A new yttrium zirconium bimetallic organic framework(YZr-MOF)adsorption material was synthesized by solvothermal method for the first time,and the structure and surface properties of adsorbents were characterized.Adsorption behavior and properties on organic phosphonate scale inhibitor 1-hydroxyethylidene-1,1-diphosphonic acid(HEDP)were investigated.Experimental results indicated that the structure of MOFs presented spherical particles of uniform size.The specific surface area of the adsorbent was 912.862 m^(2)/g.At 298 K,the theoretical maximum adsorption capacity of YZr-MOF was 66.293 mg/g(calculated in P).The adsorption process was fitted well with the pseudo-second-order kinetics equation and the Langmuir model.Moreover,the adsorption process was an endothermic process.The temperature rise was conducive to YZr-MOF adsorption of HEDP.In the adsorption experiments,the optimal amount of YZr-MOF was 0.2 g/L.YZr-MOF had good stability over a wide pH range and maintained a significant adsorption rate after six cycles.Combined with the relevant experiments and the characterization results of FTIR and XPS,electrostatic interaction and ligand exchange were the main adsorption mechanisms.