Natural zeolite characterization for adsorptive removal of ammonium ion in drinking water treatment process

Abstract

This paper mainly focuses on the removal of nitrogen in the form of ammonium ions (N-NH/) from water using a naturally occurring zeolite (NZO1) as an adsorbent. The NZ01 was well characterized by means of chemical analysis, X-Ray Diffraction (XRD) technique, X-Ray Fluorescence (XRF) spectroscopy, Scanning Electron Microscopy (SEM), Nitrogen Adsorption-Desorption (NAO) analysis, Fourier Transform Infrared (FTIR) spectroscopy and Cation Exchange Capacity (CEC) analysis. Based on the data obtained, the NZ01 is mainly composed of clinoptilolite, quartz and modernite and has cation-exchange capacity of 68cmol/kg. Batch experimental results showed that the best ammonia removal was at pH close to that of the natural water (~pH 7). The increase in initial ammonium nitrogen concentration from 5 to 50 ppm increased the adsorption capacity from 0.64 to 15.1 mg NH4+/-N/g. The kinetic and equilibrium data followed the pseudo-second order and the Langmuir isotherm, respectively. It was clearly showed from these results by comparing to other zeolites reported in literature that the NZ01 is potential to be used for the removal of ammonium ion in drinking water treatment process.