Synthesis and characterization of zeolite linde type A from rice husk ash and its application as ammonium removal

The purpose of this study is to synthesis zeolite Linde Type A (LTA) by hydrothermal method, where rice husk ash (RHA) was used as silica source and the prepared zeolite LTA is used in ammonium removal study. Nano-size zeolite LTA was successfully synthesized at aging temperature of room temperature for 72 hours followed by hydrothermal treatment at 55°C for 18 hours while micro-size zeolite was successfully synthesize by hydrothermal treatment at 110°C for 5 hours. The synthesized zeolite was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and FTIR spectroscopy. FTIR spectroscopy revealed that asymmetric vibrations of Si – O (bridging and non-bridging) bonds, vibration of symmetric stretching of tetrahedral framework, double four rings (D4R) and T – O tetrahedra. The patterns of which showed a unique characteristic of zeolite LTA were characterized by XRD. Zeolite LTA morphology observed by SEM analysis showed pseudo-spherical, face-less particles and cubic shape for nano-size and micro-size, respectively. Broad particle size ranging from 40 to 400 nm for nano-size zeolite and the average size of 1.0 to 2.5 µm for micro-size were observed. The removal of ammonium ions using zeolite LTA was found that nano-size zeolite has higher efficiency in removing ammonium ion compare to the micro-size zeolite