(727g) Ceramic Membranes for Desalination By a Vacuum Flow-through Evaporation

Purification of salty water is a huge challenge in the present times. Several membranes like GO, zeolite, and GOF membranes have been used for the purification of salt water. But limitation in terms of water flux and ion rejection demands for better methods for water purification. The atomic layer deposition (ALD) process is one type of chemical vapor deposition process based upon surface limiting chemical reaction between precursors and substrate. ALD uses alternating, self-limiting chemical reactions between gaseous precursor and a solid surface to deposit thin films in an atomic layer by layer fashion. In this work, we deposited ZnO, Al₂O₃ and TiO₂ using ALD on macroporous α-alumina disk membranes having 1 in. diameter, 1 mm thickness, and 25% porosity for the purification of salt water. We used these membranes for salty water desalination by flow-through membrane evaporation. The interaction between ALD layer and water molecules enhanced the water flux and ion rejection values. A high water flux (~100 L. m^-2. h^-1) and ion rejection rate (~99%) were obtained. Moreover, performance of ZnO, Al₂O₃ and TiO₂ ALD disk were also compared and it was found ZnO showed better performance than Al₂O₃ and TiO₂