Zeolite–Ammonium interactions: the physical-chemistry of the adsorption process

Wastewaters have plenty of organic and inorganic compounds. Most of them are nitrogen-, and phosphorus enclosing materials that can be considered plant nutrients [1]. Porous materials, such as zeolites, are considered very suitable for wastewater treatment and nutrient adsorption [2]. One potential application is the use of natural zeolites to remove nutrients, such as NH4+ from wastewater, thus reducing the risk of eutrophication of the aquatic environment and reusing enriched NH4+ zeolite as slow release fertilizer [3]. Due to the formation process, natural zeolites [2] have different operational capacity mainly related to the mineralogical composition. In this study, the ability of Slovak and Cuban zeolites with different mineralogy in adsorbing ammonium (NH4+) from a mono-component solution was assessed. Zeolites were treated or not treated with NaCl. The physical-chemistry of NH4+ adsorption process was studied by static adsorption tests, adsorption kinetics and adsorption isotherms.