Pilot study on the ceramic membrane pre-treatment for seawater desalination with reverse osmosis in Tianjin Bohai Bay

One of the critical factors for a successful seawater reverse osmosis (SWRO) process is the pre-treatment of the feed so that a stable, high-quality feed is supplied to the reverse osmosis (RO) membranes. Membrane filtration has been accepted as the preferred pre-treatment method in RO processes in recent years. In this paper, a pilot study of a pre-treatment process using a ceramic membrane for the desalination of seawater from Tianjin Bohai Bay, in the Bohai Sea of China, is presented. Different coagulation methods were compared, and the flocculation-natural sedimentation operation was determined to be the optimal method for ceramic membrane filtration. The ceramic membrane was found to work adequately in a long-term run, even under low-temperature conditions (3-6°C). Based on the permeate qualities, such as turbidity, SDI₁₅(Silt Density Index) value, and concentration of Fe, it was concluded that this ceramic membrane technology can be successfully used in SWRO processes.