酸–碱复合改性沸石对氨氮吸附性能的机制分析

Adsorption Performance and Mechanism Analysis of Ammonia Nitrogen by Acid-Base Sequential Composite Modified Zeolite

摘要: 本文主要探究柠檬酸和氢氧化钠复合改性沸石对废水中氨氮吸附能力的变化，通过考察吸附动力学、等温线以及溶液pH值、初始浓度、共存离子等因素对吸附效果的影响，揭示其吸附机理以及最佳吸附条件。研究结果表明，复合改性沸石结合了柠檬酸改性和氢氧化钠改性的优点引入了羟基和羧基，并且避免了柠檬酸堵塞孔隙和氢氧化钠破坏结构的缺点，最大吸附量达到了5.623 mg/g，大于原沸石的3.971 mg/g，复合改性沸石对氨氮的吸附机理是静电吸引、离子交换和化学络合三者的协同作用，该研究结果可为氨氮废水的吸附研究提供科学依据。

Abstract: This study primarily investigates the changes in the adsorption capacity of ammonia nitrogen in wastewater by zeolite modified with a citric acid and sodium hydroxide composite. By examining the effects of adsorption kinetics, isotherms, and factors such as solution pH, initial concentration, and coexisting ions on the adsorption efficiency, the study reveals the adsorption mechanism and optimal adsorption conditions. The results show that the composite-modified zeolite combines the advantages of citric acid modification and sodium hydroxide modification, introducing hydroxyl and carboxyl groups while avoiding the drawbacks of pore blockage caused by citric acid and structural damage induced by sodium hydroxide. The maximum adsorption capacity reaches 5.623 mg/g, which is significantly higher than the 3.971 mg/g of the original zeolite. It can be concluded that the adsorption mechanism of ammonia nitrogen by the composite-modified zeolite is the synergistic effect of electrostatic attraction, ion exchange, and chemical complexation. The findings of this study can provide a scientific basis for the research on ammonia nitrogen adsorption in wastewater.