PREPARATION OF ASYMMETRIC BILAYER CERAMIC MEMBRANE THROUGH SYNTHESIS OF GAMMA ALUMINA, ZEOLITE, SILICA AND ITS MIXTURES FOR DESALINATION APPLICATION

• Main Author: SETIAWAN - NIM : 33313003, HERI
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/27838
• Institution: Institut Teknologi Bandung

<p align="justify">Seawater desalination technology has become a solution to provide fresh water for future human’s life, whereas groundwater and surface water can’t be relied upon because of populations growing. Ceramic membrane based desalination technology is now became popular because of its exelent endurance and have good salt rejection rate compared with polymer membrane, which is normaly used in Reverse Osmosis (RO). Gamma alumina (&#947;-Al2O3), zeolite and silica are known have better mechanical strength, thermal and chemical stability compared to organic materials. Ceramic materials have also large surface area and can act as molecular sieve, so they are potential to be used as desalination membranes. This research describes the preparation techniques of ceramic asymmetric bilayer ceramic membranes for desalination applications. The first membrane was made by synthesising material of &#947;-Al2O3 and zeolite nanoparticle, to be used as coating materials. While the second coating material was made of amorphous silica modified by 1 and 2% chitosan using sol-gel method, which is calcined at 450 and 600 &#730;C. Both variations are then superimposed on the surface of porous geopolymer support with the diameter of 5 cm and the thickness of 0.8 cm. Membrane performance was evaluated by rejection rate and flux value in desalination system with salt solution (NaCl 1%) as feeder. The first coating material was prepared by synthesising of &#947;-Al2O3 and zeolites nanoparticles and made in three types, namely &#947;-Al2O3 coating (Al membrane), zeolite coating (Z membrane), and its combination (membrane Al+Z). Zeolite membrane (Z membrane) demontrated the highest salt rejection, up to 87.88%, whereas the Al+Z membrane reached 68%. The Al membrane exhibited the lowest salt rejection rate amounted 57.14%. The highest flux was obtained using Al membrane, which was to 3.43x103 L/m2h on the 54.29% rejection value; whereas the Z membrane reached 3.28x103 L/m2h on the 87.88% salt rejection value, and the lowest flux of 2.91x103 L / m2h showed by the Al+Z membrane at the 62% salt rejection value. In the preparation of the second coating material, the highest salt rejection value was obtained by silica membrane with addition 2% chitosan and calcined at a temperature 600&#730;C, ie 69.68%. It is promising to use both types of bilayer membranes as alternative ceramic membrane to be applied in the desalination.<p align="justify">