Cetylpyridinium chloride‐modified poly(ethyleneimine) for the removal and separation of inorganic ions in aqueous solution

Abstract

Abstract The removal and separation of a series of ions by the water‐soluble cetylpyridinium chloride‐modified poly(ethyleneimine) (PEI‐CPC) in conjunction with membrane filtration were investigated. The Liquid‐Phase Polymer‐Based Retention (LPR) method was applied to study the removal of the low‐molecular species at different pH values and at several element concentrations. The study comprises aqueous solutions of the anions chromate and phosphate, and of the cations Cu(II), Zn(II), Co(II), Ni(II), Cr(III), Fe(III), Cd(II), Pb(II) and Sr(II). The results show that a high retention was attained in neutral solutions for both anions and also for most metal ions investigated. PEI‐CPC exhibited good removing abilities for chromate and phosphate ions even at relatively high concentrations of anions (85 and 150 mg · L −1 , respectively) and also for most of the metal ions studied. In the case of Cu(II), Ni(II), Cd(II), and Sr(II) ions, selective interactions were observed. The polymer reagent and its interaction products were characterized by IR, UV/VIS spectrometry, and viscometry. In addition, the interaction behaviour was investigated by the retention ability. A good correlation was found between the retention data and the IR and UV/VIS spectra of the interaction products of the polymer reagent with the metal ions.