改性杨树末对水中游离和络合态Cd(Ⅱ)吸附特性研究  

Study on adsorption properties of free and complex Cd(Ⅱ)in water by modified poplar sawdust

作　　者：钱子姣 王耀增[2] 宣悦 林少华[1] QIAN Zijiao;WANG Yaozeng;XUAN Yue;LIN Shaohua(School of Civil Engineering,Nanjing Forestry University,Nanjing 210037,China;East China Branch of China International Engineering Design&Research Institute,Nanjing 210049,China)

机构地区：[1]南京林业大学土木工程学院,江苏南京210037 [2]中机国际工程设计研究院有限责任公司华东分院,江苏南京210049

出　　处：《应用化工》2024年第6期1257-1263,共7页Applied Chemical Industry

基　　金：国家重点研发计划课题(2017YFC0505803)。

摘　　要：采用溶剂法制备乙二胺四乙酸二酐改性杨树末(EPSD)吸附剂。采用SEM、FTIR和BET分析对EPSD进行了表征,并通过静态和动态吸附实验,探讨了EPSD对柠檬酸/酒石酸络合镉的吸附特性,并与对游离态镉的吸附特性进行了比较。结果表明,杨树末表面被引入羧基改性。EPSD吸附游离态和络合态Cd(Ⅱ)溶液体系的最优pH值均为6.0左右;吸附Cd(Ⅱ)的行为均符合拟二级动力学模型,主要由化学吸附控制重金属离子的吸附速率;Langmuir等温模型可以更好地描述Cd(Ⅱ)的吸附等温线,说明吸附都是单分子层的;热力学分析表明,吸附反应均为自发的吸热过程。随着进水流速增大,EPSD动态吸附游离态和络合态Cd(Ⅱ)到达穿透点的时间逐渐提前,进水流速为1.5 mL/min时最适合EPSD的动态吸附;对游离态Cd(Ⅱ)和酒石酸络合Cd(Ⅱ)的吸附容量利用率可分别达到54.93%~68.95%,53.17%~70.47%。EPSD对水中游离态和络合态Cd(Ⅱ)吸附均具有良好的应用前景。Ethylenediamine tetraacetic anhydride modified poplar dust(EPSD)adsorbent was prepared by solvent method.EPSD was characterized by SEM,FTIR and BET analysis.The adsorption properties of EPSD for citrate/tartrate complexed cadmium were discussed by static and dynamic adsorption experiments,and compared with those of free cadmium.The results showed that the surface of poplar bottom was modified by carboxyl group.The optimal pH value of EPSD adsorbing free and complexed Cd(Ⅱ)solution is about 6.0.The adsorption behavior of Cd(Ⅱ)conforms to the pseudo-second-order kinetic model,and the adsorption rate of heavy metal ions is mainly controlled by chemisorption.The Langmuir isotherm model can better describe the adsorption isotherm of Cd(Ⅱ),indicating that the adsorption is monolayer.Thermodynamic analysis shows that all adsorption reactions are spontaneous endothermic processes.With the increase of inlet flow velocity,the time for EPSD to reach the penetration point of the free state and complex state Cd(Ⅱ)is gradually advanced,and the inlet flow velocity of 1.5 mL/min is the most suitable for dynamic adsorption of EPSD.The adsorption capacity utilization of free Cd(Ⅱ)and tartaric acid complex Cd(Ⅱ)can reach 54.93%~68.95%and 53.17%~70.47%,respectively.EPSD has a good application prospect for the adsorption of both free and complex Cd(Ⅱ)in water.

关 键 词：改性杨树末 镉 静态吸附 动态吸附 

分 类 号：TQ151[化学工程—电化学工业] X505[环境科学与工程—环境工程]