Operational parameters optimization of cross-flow ceramic membrane ultrafiltration for water depyrogenation

Abstract

Water ultrafiltration has been suggested as an alternative for the removal of lypopolysaccharides in the production of Water for Injection and, Pyrogen Reduced Water. Ultrafiltration of water using an annular ceramic membrane with nominal molecular weight cut off < 50,000, has been confirmed as a viable choice for the production of such water types, producing filtrates of pyrogenic concentration below 0.03 EU/mL at permeate rates of up to 775 L/m2 -hr. Operational parameters like endotoxin feed concentration, feed rate and transmembrane pressure were assessed utilizing a factorial experimental design. The flux profiles obtained showed a linear relationship with transmembrane pressure up to the maximum concentrations studied of 667 EU/mL. Statistical evidence revealed that the permeate flux response is proportionally determined by the feed rate and transmembrane pressure main factors and the interaction of them. The endotoxin concentration was statistically identified as a non-significant factor affecting permeates flux.