Poly[1‐(2‐hydroxyethyl) aziridine] as polychelatogen for liquid‐phase polymer‐based retention (LPR)

The metal complexing properties of poly[1‐(2‐hydroxyethyl) aziridine] for the metals Co(II), Zn(II), Ni(II), Cu(II), Cr(III), Fe(III), Cd(II), Pb(II), and Sr(II) in aqueous phase were investigated. The LPR method is based on the retention of inorganic ions by soluble polymers in a membrane filtration cell and subsequent separation of low‐molecular species from the polymer complex formed. The metal interaction with the hydrophilic polymer was determined as a function of pH and filtration factor. According to the interaction pattern obtained, Cu(II) forms the most stable complexes with the polyaziridine within the pH range 3 to 7. At pH 3, it is possible to separate Cu(II) from all other metal ions. Sr(II) is only slightly retained at the pH range investigated. At pH 7, all elements, except Sr(II), did interact with the polymer and were almost quantitatively retained.