LAUSR

In this study, the effect of natural zeolite on the ammonium ion removal from landfill fresh leachate (LFL) was investigated. The effect of different parameters such as pH, contact time (CT) and zeolite concentration (ZC) in a batch system were studied to optimize ammonium ion removal from LFL by natural zeolite. Firstly, the effect of variable pH values (5–9) was investigated. In the next step, at the optimal pH condition (7), the effect of ZCs of 10–200 g/L was studied. It is indicated that, from 10 up to 80 g/L, the amount of ammonium ion removed is increased. Meanwhile, increasing of the ZC from 80 until 200 g/L resulted in decreasing removal efficiency. Finally, in the previous optimal conditions, the role of CTs (5–300 min) is inspected. With increasing CT from 5 up to 30 min the amount of removal rate was increased. Following with increasing CT, the intensity of the uptrend decreased and the removal rate reached a steady state. Results of the experiments indicate optimal conditions for ammonium ion removal from LFL (44.49%) occur at pH, 7, ZC of 80 g/L and CT of 30 min. In addition, the adsorption isotherm and kinetics confirmed that the Langmuir isotherm (R2 = 0.9451) was more consistent than the Freundlich isotherm (R2 = 0.9211). This study indicates that clinoptilolite zeolite (CZ) as an inexpensive and suitable adsorbent, has a good potential for removing ammonium ions from LFL solution.