莫静宇,向平,李梦颖,陈昊天,李玉平,周元.Ac-Co/UiO-66对水中阴离子染料的吸附性能[J].环境科学学报,2021,41(7):2740-2747
Ac-Co/UiO-66对水中阴离子染料的吸附性能
- Performance of Ac-Co/UiO-66 on adsorption of anionic dyes in aqueous solution
- 基金项目：中央高校基本科研业务费专项资金资助项目（No.2018CDPTCG001/48）
- 莫静宇
- 重庆大学三峡库区生态环境教育部重点实验室, 重庆 400045
- 向平
- 重庆大学三峡库区生态环境教育部重点实验室, 重庆 400045
- 李梦颖
- 重庆大学三峡库区生态环境教育部重点实验室, 重庆 400045
- 陈昊天
- 重庆大学三峡库区生态环境教育部重点实验室, 重庆 400045
- 李玉平
- 重庆大学三峡库区生态环境教育部重点实验室, 重庆 400045
- 周元
- 重庆大学三峡库区生态环境教育部重点实验室, 重庆 400045
- 摘要：通过溶剂热法在醋酸改性的条件下制备合成了新型钴掺杂的UiO-66纳米颗粒（Ac-Co/UiO-66），并采用SEM、XRD和BET分析证实了材料主体结构的合成.同时，以阴离子染料直接蓝、达旦黄和刚果红为目标污染物，系统研究了吸附时间、初始浓度、pH因素对Ac-Co/UiO-66吸附效果的影响.结果表明，吸附进行120 min后3种染料的吸附量趋于平衡，吸附过程均符合拟二级动力学模型，证明化学吸附是主要的速率控制步骤.3种染料的吸附等温数据均采用Langmuir等温线模型拟合效果较好，证明染料分子在Ac-Co/UiO-66上属于单层吸附，直接蓝、达旦黄和刚果红的Langmuir最大吸附容量分别为378.3、525.8、1234.6 mg·g-1.Ac-Co/UiO-66适合在酸中性环境去除染料.在二元染料体系中发现阴离子染料之间的吸附具有拮抗效应，且染料浓度比的增大会导致染料的竞争效应向独立效应演变.染料的吸附机理涵盖了氢键作用、静电作用及π-π堆积作用力.Ac-Co/UIO-66对直接蓝、达旦黄和刚果红的吸附容量经历4个循环后分别维持在71.2%、65.3%和91.4%.
- Abstract：A kind of new cobalt-doped UiO-66 nanoparticle was prepared and synthesized by using solvothermal method under the condition of acetic acid modification, and the XRD、SEM and BET proved the successful synthesis of the main structure of the material. The effects of adsorption time, initial concentration and pH factors on the adsorption effect were systematically investigated using the anionic dyes Direct Blue, Titan Yellow and Congo Red as the target pollutants. The three dyes reached equilibrium after 120 minutes of adsorption, and the adsorption process conformed to the pseudo-second-order kinetic model, which proved that chemical adsorption was the main rate control step. The adsorption isotherms of dyes were highly fitted to Langmuir isotherms, which proved that the adsorption of dye molecules on Ac-Co/UiO-66 was monolayer adsorption, and the Langmuir maximum adsorption capacities of the three dyes were 378.3, 525.8 and 1234.6 mg·g-1, respectively. Ac-Co/UiO-66 was suitable for removing dyes in acid-neutral environments. The adsorption between anionic dyes appeared antagonistic effect in the binary dyes system, and the increase of the dye concentration ratio in the binary dyes system will cause the competition effect of the dyes to evolve to the independent effect. The adsorption mechanism of dyes included hydrogen bonding, electrostatic interaction and π-π stacking interaction. After four cycles, the adsorption capacity of Ac-Co/UIO-66 for direct blue, titan yellow and Congo red were remained at 71.2%, 65.3% and 91.4%, respectively.
