Kinetic and Isotherm Study of Ammonium Sorption Using Natural Zeolites from Lampung

Abstract

The aims of the study were to characterize and investigate the ammonium adsorption kinetic and isotherm of the natural zeolites from Lampung. Characterization of the natural zeolite was performed by using X-Ray Diffraction (XRD), nitrogen-physisorption, Scanning Electron Microscope (SEM) and X-Ray Fluorescence (XRF). According to XRD analysis, the natural zeolites were identified as clinoptilolite dominant phase with some impurities i.e. mordenite and quartz. The surface area calculated by BET model was 45 m2/g. The SEM images showed the irregular morphology shape. The XRF analysis revealed that the ratio Si/Al was 6.2. Ammonium sorption experiment was performed by using 100 ppm of ammonium solution in the batch reactor with variation on natural zeolite mass loading and adsorption time. Ammonium adsorbed onto the zeolites was increased with the adsorption time and mass loading. The kinetic models, i.e. Lagergren’s 1st order, Pseudo 2nd order, Elovich, Intraparticle diffusion, and isotherm models, i.e., Langmuir, Langmuir-Vageler, Freundlich, Temkin were fitted with the ammonium adsorption kinetic data by using non-linear regression analysis in MATLAB.