Isolation or Concentration of Organic Substances from Water - An Evaluation of Reverse Osmosis Concentration

摘要

This study describes the development and evaluation of a reverse osmosis (RO)/Donnan dialysis system to be used in the preparation of drinking water concentrates for biological testing. Two reverse osmosis membranes, cellulose acetate (Osmonics, Inc.) and FT-30 (Film Tec, Inc.), were selected for laboratory evaluation, primarily because of their purported short-term chlorine resistance. Two Donnan membranes, Nafion (Dupont) and MA 3475 (IONAC), were chosen for further study based upon their chemical resistance characteristics (chlorine, caustic, and acid tolerance). The FT-30 membrane, a thin-film composite, demonstrated a substantially greater rejection efficiency for the model compounds than the cellulose acetate membrane. As expected from the rejection data, the recoveries of model solutes were much better for the FT-30 membrane system than the cellulose acetate system. Overall the recovery values (2-74%) were poor for the majority of model compounds in both RO systems and substantially less than anticipated based on the rejection data.