This study investigates the nitrogen transformationNitrogen transformation dynamics and removal characteristics of the anaerobic ammonium oxidation (AnammoxAnammox) process in a zeolite-packed bioreactorZeolite-packed bioreactor. Through 90 days continuous monitoring, the effects of zeolite packing ratios (10, 20, 30%) on concentration variations of ammonia nitrogen ( \({\text{NH}}_{4}^{ + } {\text{ - N}}\) ), nitrite nitrogen ( \({\text{NO}}_{2}^{ - } {\text{ - N}}\) ), nitrate nitrogen ( \({\text{NO}}_{3}^{ - } {\text{ - N}}\) ), and total nitrogen (TN) were systematically analyzed. Results demonstrated that with increasing packing ratios, effluent ammonia nitrogen ( \({\text{NH}}_{4}^{ + } {\text{ - N}}\) ) concentration decreased from 56.04 to 24.77 mg/L, accompanied by a rise in \({\text{NH}}_{4}^{ + } {\text{ - N}}\) removal efficiency from 50.49 to 79.27%. Nitrite nitrogen ( \({\text{NO}}_{2}^{ - } {\text{ - N}}\) ) concentration peaked at 0.84 mg/L under the 20% packing ratio, while total nitrogen (TN) removal efficiency significantly improved from 20.82 to 54.64%, with effluent TN reduced to 45.90 mg/L. Nitrogen removalNitrogen removal efficiency is synergistically enhanced by ion exchange and biofilm adsorption to improve readability, with higher packing ratios significantly enhancing the anaerobic ammonium oxidation (AnammoxAnammox) reaction. This study revealed that at a 30% packing ratio, the system achieved high-efficiency nitrogen removalNitrogen removal through the synergistic interaction of physical adsorption and biological denitrification. The findings provide critical process parameters and mechanistic insights for the application of zeolite-packed bioreactorsZeolite-packed bioreactor in nitrogen-laden wastewater treatment, highlighting packing ratio optimization as a key factor in balancing nitrogen removalNitrogen removal efficiency with system stability.