摘 要
铅离子污染是水体环境中亟待解决的重要问题之一，其对生态系统和人类健康的潜在威胁日益受到关注。为实现高效去除废水中铅离子的目标，本研究以改性沸石为吸附剂，系统探讨了其对铅离子的吸附行为，并建立了相应的等温吸附模型与热力学分析框架。研究采用酸改性和热处理相结合的方法制备改性沸石，通过表征手段验证了材料表面性质的变化及其对吸附性能的影响。实验在不同温度、pH值、初始浓度及接触时间条件下进行，结果表明改性沸石对铅离子具有显著的吸附能力，且吸附过程符合准二级动力学模型，说明化学吸附为主要机制。Langmuir等温吸附模型能够较好地描述吸附过程，计算得到的最大吸附量为42.31 mg/g，远高于未改性沸石的吸附容量。此外，热力学参数分析显示，该吸附过程为自发吸热反应，ΔG0表明反应具有良好的自发性，而ΔH>0和ΔS>0进一步揭示了吸附过程的热力学本质。本研究的创新点在于结合改性技术优化沸石结构，显著提升了其对铅离子的吸附性能，并通过理论模型与实验数据的对比验证了吸附机制的合理性。研究成果为改性沸石的实际应用提供了理论依据和技术支持，同时为重金属废水处理领域的材料开发和工艺优化提供了新思路。关键词：改性沸石；铅离子吸附；Langmuir模型；热力学分析；准二级动力学
Abstract
Lead ion pollution is one of the critical issues in aquatic environments that urgently need to be addressed, as its potential threats to ecosystems and human health are increasingly drawing attention. To achieve the goal of efficiently removing lead ions from wastewater, this study employed modified zeolite as an adsorbent to systematically investigate its adsorption behavior towards lead ions and established a corresponding isothermal adsorption model along with a thermodynamic analysis fr amework. The modified zeolite was prepared by combining acid modification with heat treatment, and characterization methods were used to verify the changes in surface properties and their influence on adsorption performance. Experiments were conducted under varying conditions of temperature, pH, initial concentration, and contact time. The results demonstrated that the modified zeolite exhibited significant adsorption capacity for lead ions, and the adsorption process followed the pseudo-second-order kinetic model, indicating that chemical adsorption was the dominant mechanism. The Langmuir isothermal adsorption model adequately described the adsorption process, with a calculated maximum adsorption capacity of 42.31 mg/g, which was considerably higher than that of unmodified zeolite. Furthermore, thermodynamic parameter analysis revealed that the adsorption process was a spontaneous endothermic reaction, as evidenced by ΔG 0, which indicated favorable spontaneity, and ΔH > 0 and ΔS > 0, which further elucidated the thermodynamic nature of the adsorption process. The innovation of this study lies in optimizing the structure of zeolite through modification techniques, significantly enhancing its adsorption performance for lead ions, and validating the rationality of the adsorption mechanism through comparisons between theoretical models and experimental data. The research findings provide theoretical support and technical guidance for the practical application of modified zeolite and offer new insights into material development and process optimization in the field of heavy me tal wastewater treatment..
Key Words：Modified Zeolite；Lead Ion Adsorption；Langmuir Model；Thermodynamic Analysis；Pseudo-Second-Order Kinetics
目 录
摘 要 I
Abstract II
第1章 绪论 2
1.1 改性沸石吸附铅离子的研究背景与意义 2
1.2 改性沸石吸附铅离子的国内外研究现状 3
1.3 本文研究改性沸石吸附铅离子的方法 3
第2章 改性沸石吸附铅离子的实验设计与方法 5
2.1 实验材料与改性方法的选择 5
2.2 吸附实验的设计与操作流程 5
2.3 数据分析方法与模型选择 6
2.4 热力学参数计算方法 7
第3章 改性沸石吸附铅离子的等温模型研究 9
3.1 等温吸附模型的基本原理 9
3.1.1 Langmuir模型的应用条件 9
3.1.2 Freundlich模型的适用范围 10
3.1.3 Temkin模型的特点分析 10
3.1.4 Dubinin-Radushkevich模型的探讨 11
3.2 不同等温模型的拟合结果分析 11
3.2.1 模型拟合优度的比较 11
3.2.2 最佳模型的选择依据 12
3.2.3 吸附容量的计算与验证 12
3.2.4 模型参数的物理意义解读 13
3.3 等温模型对实际应用的指导价值 13
第4章 改性沸石吸附铅离子的热力学研究 15
4.1 热力学研究的基本理论框架 15
4.1.1 自由能变化的计算方法 15
4.1.2 熵变与焓变的分析方法 15
4.1.3 温度对吸附过程的影响机制 16
4.1.4 热力学平衡常数的确定 16
4.2 吸附过程的热力学参数计算与分析 17
4.2.1 ΔG值的变化规律及其意义 17
4.2.2 ΔH值的计算与吸附类型判断 17
4.2.3 ΔS值的分析与吸附机理推测 18
4.2.4 温度对ΔG、ΔH和ΔS的影响 18
4.3 热力学研究对吸附性能的评价 18
4.3.1 吸附过程的自发性分析 19
4.3.2 吸附过程的可逆性探讨 19
4.3.3 热力学参数对改性效果的评估 20
结 论 20
参考文献 21
致 谢 22
