Evaluation of heavy metal ions removal from acidic waste water streams

• Iminodiacetate resins were used for heavy metals (HM) ions removal from solutions.
• The sorption was favoured at pH range of 4.0–7.0 and high concentrations of NaCl.
• Recommendation to use Lewatit TP 207 and Lewatit TP 208 as effective ion exchangers was made.

This study presents some purification processes of acidic waste streams including such heavy metals as Cu(II), Zn(II) and Ni(II) in the low and adjusted pH range as well as high NaCl concentrations, which are typical industrial conditions. A novel approach to the assembly of previously used processes skips the step of pH adjustment of the treated waste streams, which further reduces maintenance costs of waste streams.The study was conducted using macroporous ion exchange resins based on the polystyrene–divinylbenzene matrix: Lewatit TP 207 and Lewatit TP 208 – the chelating ion exchangers with the iminodiacetate functional groups and the medium base anion exchange resin Lewatit MonoPlus MP 64 with the quaternary ammonium and tertiary amine functional groups. Ion exchangers are characterized by high resistance to osmotic shock. The macroporous structure provides an ideal diffusion of Cu(II), Zn(II) and Ni(II), allowing the efficient exhaustion and regeneration. Beside the commercial form, Lewatit TP 207 and Lewatit TP 208 were used in the mono- and disodium forms.