AROMATIC POLYAMIDE TYPE POLYMERIC MEMBRANES FOR BRACKISH AND SEA-WATER DESALINATION

High solute rejecting asymmetric membranes prepared from freshly synthesized polyamide hydrazide (PAH) and polyetheramide hydrazide (PEAH) polymers for desalination of brackish water and sea water have been reported from our laboratory. The membranes offer around 98% and 99.4% salt rejection respectively for sea water under reverse osmosis condition. The synthesis of PAH polymer has since been carried out successfully in 1 kg per batch scale and a large number of sheet membranes have been prepared under carefully controlled conditions and used in desalination modules. The paper outlines the salient features of synthesizing the polymers on a large scale, membrane making and the RO performance obtained in plate module RO unit using high saline brackish water feeds.