UV spectrophotometric studies of cu(II) ions separation by ultrafiltration enhanced with poly(sodium acrylate)

Polymer-enhanced ultrafiltration is an effective separation technique which enables heavy metal ions removal from aqueous solutions. In this work, a water soluble polymer containing carboxylic groups and poly(sodium acrylate) (PSA), was used to enhance the separation of Cu(II) ions during ultrafiltration. The UV spectrophotometric analysis of the solutions containing PSA and Cu(II) ions revealed an absorption band with its maximum at a wavelength of 255 nm. The methods of continuous variations (Job’s method) and molar ratio were employed to assess the stoichiometry of PSA-Cu(II) complexes formed. The molar ratio of PSA repeat unit to Cu(II) ion was evaluated to be ca. 2.8-2.9. The effect of the polymer- metal concentration ratio, solution pH, and the presence of anions: Cl^-, SO^2- ₄, CO^2- ₃, PO^3- ₄, as well as a complexing agent (EDTA) on copper ions separation was investigated. The study revealed a good compatibility of spectrophotometric analysis and the ultrafiltration results.