CORD MEMBRANE - A NEW REVERSE-OSMOSIS MEMBRANE CONFIGURATION

A new Reverse Osmosis Membrane Configuration called as Cord Membrane ( CM ) was developed. These membranes fall in the category of small diameter tubes comprising an external membrane coated on cylindrical support but differs from the others in their flexibility and support characteristics. The membranes were prepared by coating a mixture of cellulose diacetates on specially prepared cords, which are made out of flexible strings of polymer fibres. Cords made out of a bundle of nylon guts covered with a seamless polyethylene net which in turn was covered by polyester fiber coating, were found to be suitable for the preparation of these membranes. The membranes prepared by using the mixed dope of the cellulose acetates can be used for phenol rejection. At 30 kg/cm2 the membranes gave a salt rejection of 80% with 0.85 m3/m2 (d) flux. After a continuous operation for 4 hours the flux dropped to 0.76 m3/m3 (d) the rejection remaining the same. The preparation of cords, casting of membranes and their testing are discussed in this paper.