Removal of ammonium ion from aqueous solution by natural Turkish (Yildizeli) zeolite for environmental quality

The purposes of this study were to investigate the removal efficiency of ammonium (NH(4)(+)) ion from aqueous solution using the natural Turkish (Yildizeli) zeolite and to characterize equilibrium isotherms. Experiments were carried out using batch method as a function of the solution pH, shaking time, dosage of adsorbent, and temperature. All these factors affected NH(4)(+) ion removal from aqueous solution. Equilibrium modelling data were fitted to linear Langmuir and Freundlich models. Dubinin-Redushckevich (D-R) isotherm was applied to describe the nature of ion exchange of NH(4)(+) and found that it occurred physically. Thermodynamics parameters such as change in free energy (DeltaG degrees ), enthalpy (DeltaH degrees ) and entropy (DeltaS degrees ) were also calculated. These parameters confirmed that ion exchange of NH(4)(+) by the zeolite was feasible, spontaneous and exothermic in nature. Based on the results, it can be concluded that the natural Turkish (Yildizeli) zeolite is suitable for the removal of NH(4)(+) ions in wastewater treatments and agricultural purposes to in terms of sustainability of environmental quality.