PEI改性沙柳对水中酸性铬兰K的吸附作用研究  

Investigation into the Adsorption Mechanism of Acid Chrome Blue K in Aqueous Solution Using Polyethyleneimine Modified Salix

作　　者：张晓羽 郭红博 邹卫华[1] ZHANG Xiaoyu;GUO Hongbo;ZOU Weihua(School of Chemical Engineering, Zhengzhou University, Zhengzhou 450001, China)

机构地区：[1]郑州大学化工学院,河南郑州450001

出　　处：《郑州大学学报（工学版）》2022年第3期87-92,共6页Journal of Zhengzhou University（Engineering Science）

基　　金：河南省基础与前沿技术研究计划项目(162300410016)。

摘　　要：以环氧氯丙烷为交联剂制备聚乙烯亚胺/沙柳(PEI-SP)吸附剂,研究其对水中阴离子染料酸性铬兰K(ACBK)的吸附行为,采用吸附动力学模型和吸附等温线模型对实验数据进行拟合分析。动力学模型拟合结果表明:PEI-SP对ACBK的吸附过程符合Elovich模型,该吸附过程为非均相化学吸附过程且膜扩散为吸附过程的主要速率控制步骤。等温线模型拟合结果表明:Koble-Corrigan模型能很好描述PEI-SP对ACBK的吸附过程,说明PEI-SP对ACBK的吸附主要以单分子层吸附为主,同时也存在多分子层吸附。在298 K时,根据Langmuir模型计算PEI-SP对ACBK的最大单分子层吸附量为0.428 mmol/g。通过pH值对吸附量的影响可以看出,随着pH值的增加PEI-SP对ACBK的吸附量逐渐降低。当pH<6.78时,ACBK分子主要通过静电吸引作用吸附在PEI-SP表面。通过对吸附前后PEI-SP的红外光谱以及pH值对吸附性能的影响进行分析可知,PEI-SP对ACBK的吸附机理为静电吸引作用、氢键以及π—π堆叠作用。解吸再生实验结果表明:吸附剂经过3次吸附/解吸附循环仍可维持吸附性能,显示出良好的再生性能,该吸附剂在处理阴离子染料废水方面具有良好的应用前景。Polyethylenimine/Salix(PEI-SP)was prepared by epichlorohydrin crosslinking for application in the adsorption of acid chrome blue K(ACBK)from aqueous solution.The adsorption kinetic models and the adsorption isotherm models were used to fit the obtained experimental data,respectively.The results showed that the kinetic process was best predicted by the Elovich model,which indicated the adsorption process was an inhomogeneous chemisorption process and the adsorption rate was controlled by film diffusion.The equilibrium isotherm was best fitted with the Koble-Corrigan model,which indicated that the adsorption of ACBK by PEI-SP was mainly monolayer adsorption,while accompanied by multi-molecular layer adsorption.The maximum adsorption capacity of PEI-SP calculated by Langmuir model for ACBK was 0.428 mmol/g at 298 K.As could be seen from the influence of pH value on the adsorption capacity,the adsorption capacity of PEI-SP on ACBK gradually decreased with the increase of pH value.When pH<6.78,ACBK was mainly adsorbed on the surface of PEI-SP by electrostatic attraction.Combining the results of the infrared analysis and the effects of pH values on the adsorption capacity,the adsorption mechanism of ACBK on PEI-SP were electrostatic interaction,hydrogen bonding,andπ—πstacking interactions.The results of desorption and regeneration experiments showed that the adsorbent could retain its adsorption capacity after three cycles operations,showing excellent regenerability.It was implied that PEI-SP has a promising application in the removal of anionic dyes from wastewater.

关 键 词：聚乙烯亚胺/沙柳(PEI-SP) 吸附 酸性铬兰K 吸附机理 

分 类 号：X703[环境科学与工程—环境工程]