Column Adsorption Studies for the Removal of Ammonium Using Na-Zeolite-Based Geopolymers

The aim of this study was to examine the removal of ammonium ions from a synthetic model solution by using Na-zeolite-based geopolymers. Na-zeolite (=analcime) is a residue from mining industry. Three adsorbents were prepared from Na-zeolite using different production steps and metakaolin as a blending agent. These novel adsorbents were investigated in a fixed-bed column system where the effects of different flow rates with the initial ammonium concentration of 40 mg/L were studied. The Thomas, Bohart–Adams and Yoon–Nelson breakthrough curve models fitted well with the experimental data with a high R2 value. After adsorption experiments, adsorbents were regenerated using a mixture of 0.2 M …