无机-有机复合材料沸石@聚丙烯酰胺的制备及对Pb^(2+)的吸附研究  

Synthesis of the Inorganic-Organic Composite Zeolite@Polyacrylamide Materials and Its Application on the Lead Adsorption

作　　者：李婉君 李世敏 马德彪 李换换 LI Wanjun;LI Shimin;MA Debiao;LI Huanhuan(Department of Chemistry and Chemical Engineering,Taiyuan Institute of Technology,Taiyuan,Shanxi 030008,China)

机构地区：[1]太原工业学院化学与化工系,太原030008

出　　处：《中国无机分析化学》2024年第5期530-537,共8页Chinese Journal of Inorganic Analytical Chemistry

基　　金：山西省大学生创新创业项目(S202314101083);山西省‘1331’工程资助项目。

摘　　要：重金属污染会引起严峻的环境问题。因此,必须对重金属离子进行测定,但由于重金属离子的含量低并受基体效应影响,检测前需要先将其分离富集。利用一锅法制备沸石@聚丙烯酰胺复合材料,将其作为分离富集材料,结合火焰原子吸收光谱仪,研究对Pb^(2+)的吸附性能。为了得到最佳的吸附性能,对制备条件中的沸石用量进行了优化,并对优化后的复合材料进行了扫描电镜、热重分析和比表面积表征。利用单一变量法,对固相萃取条件中的溶液pH值和振荡时间进行了优化。研究了复合材料在吸附Pb^(2+)过程中的动力学模型、等温线模型和热力学参数。结果表明:在沸石用量为333 mg/g,溶液pH值为5和振荡时间为80 min时,复合材料的吸附效率最佳;沸石@聚丙烯酰胺复合材料吸附Pb^(2+)的过程符合二级动力学和Freundlich模型,且在298.15 K时,热力学参数ΔH=15614.18 J/mol、ΔS=65.2 J/(mol·K)、ΔG=-1878.059 J/mol,是一个吸热且熵增的自发过程;此外,复合材料经过连续三次吸附和解吸实验,对Pb^(2+)的吸附量基本不变,且解吸率保持在89.7%以上,说明沸石@聚丙烯酰胺复合材料具有较好的再生性能。The pollution of heavy metal pollution can cause serious environmental problems.Hence,it is required to determine the content of heavy metal ions.Nevertheless,owing to the low concentration and matrix effects,it is necessary to separate and enrich heavy metal ion before the analysis.In this study,the zeolite@polyacrylamide composite materials were synthesized by the one-pot polymerization as the separation and enrichment material,combining with flame atomic absorption spectrophotometer,researched on the adsorption performance of Pb^(2+).In order to find the optimal adsorption performance,the amount of zeolite used in the preparation conditions was optimized.The optimized composite was characterized by scanning electron microscope,thermogravimetric analysis,and specific surface area.The single variable method was used to optimize the solution pH and oscillation time in solid-phase extraction conditions.The adsorption kinetics,isotherms,and thermodynamics of the composites for the adsorption of Pb^(2+)were investigated.The results showed that the adsorption efficiency of the composites was optimal,when the dosage of zeolite was 333 mg/g,the solution pH was 5,and the oscillation time was 80 min.The adsorption process of Pb^(2+)on zeolite@polyacrylamide composites was accorded with the second-order kinetics and Freundlich model,and was also an endothermic,entropy increasing,and spontaneous process,when the temperature was 293.15 K,the values of thermodynamic parameters were ΔG of-1878.059 J/mol,ΔS of 65.2 J/(mol·K),and ΔH of 15614.18 J/mol.Otherwise,the adsorption quantity of Pb^(2+)remained basically unchanged and the desorption ratio of lead still reached above 89.7% after the adsorption and desorption cycles of 3 times on composites,indicating that the composites had the good regeneration performance.

关 键 词：无机-有机复合材料 固相萃取法 火焰原子吸收光谱法 Pb^(2+) 

分 类 号：O657.31[理学—分析化学] X832[理学—化学]