Optimization of NS-100 membrane for reverse osmosis.

Abstract

The optimization of a newly developed reverseosmosis membrane, NS-100, was studied based upon two series of statistically designed experiments. A total number of 33 experiments was run to evaluate the effects and interaction effects of five independent casting variables. With the aid of a constrained optimization method, SUMT algorithm, the optimum conditions for all casting variables was determined. Flat-sheet membranes cast under these conditions yielded a permeate flux of 10.30 + or ! 1.95 gal/ftSUB2-day (gfd) and a 99.30 + or ! 0.18% rejection of salt under a pressure of 600 lb/inSUB2 (psig). Tubular membranes, on the other hand, yielded a flux of 10.13 + or ! 3.19 gfd and a 98.51 + or ! 0.66% rejection of salt. These performances evidently indicate that the optimized Ns-100 membrane is superior to those previously developed. The satisfactory performance of tubular membranes indicates the feasibility of applying the results found in this study for the fabrication of tubular modules. (A)