Adsorption performance of modified natural zeolite for ammonia nitrogen: A Mini-review

Ammonia nitrogen contamination in water systems poses significant environmental challenges due to its toxicity and persistence. Natural zeolites, particularly clinoptilolite, offer promising adsorption capabilities owing to their porous structure and ion-exchange properties. This review summarizes recent advances in the use of modified natural zeolites for ammonia nitrogen removal, focusing on various modification strategies such as acid treatment, alkali activation, surfactant functionalization, and metal loading. It also highlights the influencing factors affecting adsorption efficiency, such as pH, contact time, competing ions, and zeolite dosage. The review further discusses the regeneration and reusability of modified zeolites, outlining challenges and future directions for optimizing these materials in large-scale water treatment applications. This review comprehensively analyzes recent advances (2010-2024) in natural zeolite modification for enhanced ammonia nitrogen removal. We systematically evaluate thermal, chemical, and combined modification methods, demonstrating that sodium-based treatments consistently achieve >90% removal efficiency through optimized ion exchange capacity. The work details structure-property relationships in zeolites, with clinoptilolite showing particular promise due to its unique pore geometry. We present new comparative data showing NaCl-La (OH)₃ modified zeolites achieve 92.6% removal at optimal conditions (pH 6.0, 12.5 g/L dosage). The review further examines competing ion effects, revealing K⁺ reduces adsorption capacity by 30% compared to Mg²⁺. Emerging techniques like ultrasonic-assisted modification show exceptional promise (>99% removal). Practical applications across municipal, industrial, and agricultural wastewater streams are critically reviewed, with cost-benefit analysis of regeneration methods. The work concludes with standardized testing protocols and identifies key research gaps in field-scale implementation of modified zeolites.