Evaluation of Asymmetric Hollow Fibers for Desalination by Reverse Osmosis.

摘要

Asymmetric hollow fiber membranes with the discriminating skin on the inside of the fiber were prepared from aromatic polyamides (Nomex) and cellulose acetate. These fibers has an inside diameter of 0.018in. and a wall thickness ranging from 0.002in. to 0.007in. Nomex fibers gave water flux rates of 20 GSFD at 40% magnesium sulfate and 20% sodium chloride rejection levels when tested with a 1500ppm brackish feed brine. The burst pressure of these fibers averaged 150psig. Initial attempts at producing cellulose acetate fibers resulted in fibers which exhibited very poor burst strength,less than 25psig in most cases,and no NaCl rejection with very low salt concentrations. A secondary product of the project was a single fiber testing device which allowed screening of candidate fibers immediately after spinning,without having to wait for a module to be potted. (Author)