Abstract
Reverse osmosis and ultrafiltration processes have greatly developed owing to the numerous researches on membranes and modules which have been continued since the establishment of the first commercial RO plants in 1970. Nowadays, many researchers and technicians recognize that the seawater desalination by RO process of a single stage or a dual stage, which was previously considered to be difficult from the economical viewpoint, has a bright prospect as a energy-saving process. In-situ formed composite membranes are developed and partially employed in a large commercial plant in the place of the cellulose acetate or polyamide membranes.
Considering these circumstances, the present status of membrane technology of desalination in Japan and United States and new membranes for desalination are described here based on the recently published reports and Japanese patents.
