Extraction of Organic Compounds from Aqueous Solutions by the Nanofiltration Method

Abstract

Extraction from aqueous solutions of oxalate and ethylenediaminetetraacetate (EDTA) ions, anionic (ASF) and nonionogenic (NSF) surfactants, and a complex of Co(III) with EDTA by the nanofiltration (NF) method was studied. It was shown that 98–99% of NSFs and EDTA, 85–90% of ASFs and oxalate ions, and 76–79% of the Co(III)–EDTA complex can be extracted with the use of a polymeric NF membrane. The possibility is demonstrated of effectively extracting EDTA and oxalate ions with an NF membrane at solution pH varied within the range 1–13 and sodium nitrate concentrations of 0 to 159 g/dm3. A conclusion is made that using the nanofiltration method is promising for effective removal of various organic complexing and surface-active substances and the Co(III)–EDTA complex from solutions with complex salt composition.