David B. Pall

Particulate retention by bacteria retentive membrane filters

Abstract Membranes are widely used in and accepted by industry as capable of 0.2 and 0.22 μm absolute removal of bacteria and particulates. Conditions are establised in this study under which these membranes pass latex spheres 0.5 μm and larger in diameter. The conditions of penetration, as a function of membrane type, challenge conditions, and pH are reported, and the interactions between the membrane pore surfaces and the latexes are related to DLVO theory. The study indicates that membranes of pore diameter substantially smaller than those now in common use increase the probability of obtaining microbial sterility.