Performance of porous cellulose acetate membranes for the reverse osmosis treatment of hard and waste waters

Abstract

Abstract : The performance of a few typical Loeb-Sourirajan type porous cellulose acetate membranes is reported for the treatment of hard, polluted, and sewage waters. The membranes used are specified in terms of pure water permeability constant and solute transport parameter for sodium chloride. Using feed waters containing 300- to 800-p.p.m. hardness (expressed as CaCO3), product waters containing 2 p.p.m. or less could be obtained with 90% product recovery and an average initial flux of 38 gallons per day per sq. foot at 1000 p.s.i.g. The possibility of producing 'ultrapure' waters by repeated reverse osmosis processing is indicated. The separation of common pollutants such as nitrates, borates, fluoride, alkyl benzene sulfonate (ABS), ammonia, and phosphates, and a few others usually present in plating wastes, and the applicability of the reverse osmosis process for the treatment of sewage waters and water renovation are illustrated. (Author)