Development and stability of gelatin cross-linked membranes for copper (II) ions removal from acid waters

The aim of this work was to develop bio-sourced membranes suitable for heavy metals extraction under acidic solutions. For this purpose cross-linked gelatin membranes were synthetized and tested to carry out copper (II) ions extraction from aqueous acidic solutions as a model. Gelatin membranes were cross-linked with three different compounds: terephthalaldehyde (TPA), ferulic acid (FA) or glutaraldehyde (GTA) in vapor phase. Both gelatin-TPA and gelatin-FA membranes showed a weak resistance in aqueous medium though gelatin-GTA membranes were very stable and resistant to acidic conditions. A preliminary study of copper (II) permeation showed that gelatin-GTA membranes were very permeable whereas they are slightly affected by the acidity of the aqueous medium and very efficient for the transfer of copper (II) ions at low concentrations.