Use of natural zeolite for ammonium ion removal from aqueous solution

This study assesses the potential of natural Mongolian clinoptilolite for ammonium ion removal from aqueous solution. The effect of relevant parameters, such as pH, adsorbent dosage, contact time and initial ammonium concentration was examined, respectively. The results show that pH contributes to ammonium removal efficiency as it can influence both the character of the exchanging ions and clinoptilolite itself, ammonium removal by clinoptilolite occurs rapidly within the first 15 minutes of contact time, the ammonium removal capacity of clinoptilolite increases with the increase of the initial ammonium concentration. Langmuir and Freundlich models were applied to describe the equilibrium isotherms of ammonium uptake. Freundlich model correlates very well with the experimental data. Based on the results, it can be concluded that natural zeolite is suitable for the removal of NH 4+ ions in sewage.