Brackish water treatment by ceramic TiO2 low-pressure nanofiltration membranes

Abstract

The application of ceramic Nanofiltration (NF) membrane in brackish water treatment is increasing due to strict water quality standards. The Ceramic NF membrane process is widely used nowadays and has replaced reverse osmosis (RO) membranes in many applications due to lower energy consumption and higher flux rates. This work aims to study tubular ceramic TiO2 nanofiltration membrane separation performance for single and tertiary salt mixtures at low-pressure (2 bar). The results showed that the ions rejection is ordered as follows: R (Cl1-) ion size > R calcium (Ca2+) ion size > R sodium (Na1+) ion size > R magnesium (Mg2+) ion. The highest Cl1- rejection was 46%, the highest Ca2+ and Mg2+ rejection was 44%, and the highest Na1+ rejection was 37%. The pure water flux through the investigated ceramic NF membrane for distilled water was calculated to be 5.29 x 10-7 m3 s-1 m-2 bar-1, and the flux was dropped down for the salt mixture feed to 2.56 x 10-7 m3 s-1 m-2 bar-1 due to the presence of salt particles in the feed.