Electroextraction of Pb 2+ ions from diluted solutions by a process combining ion-exchange textiles and membranes

• Published in: Desalination Vol. 120; no. 3; pp. 175 - 184
• Main Authors: Basta, K., Aliane, A., Lounis, A., Sandeaux, R., Sandeaux, J., Gavach, C.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 1998
• Subjects: Electroextraction; Electroregeneration; Ion-exchange membrane; Ion-exchange textile; Lead ion; Low concentration; Ion-exchange membrane; Lead ion; Electroextraction; Electroregeneration; Low concentration; Ion-exchange textile
• ISSN: 0011-9164; 1873-4464
• DOI: 10.1016/S0011-9164(98)00216-1

The extraction of Pb 2+ ions from diluted solutions was achieved using a hybrid process combining cation exchange textiles, ion-exchange membranes and electric current. Two methods were investigated: an electroextraction process in two steps where the fixation of Pb 2+ ions was followed by electroregeneration of the cation-exchange textiles; the second one a continuous electroextraction process where the ion exchange and regeneration take place simultaneously. For these electroextraction processes, the cation-exchange textile is introduced into an electrodialysis cell and compressed between two cation-exchange membranes. Under an applied current, the Pb 2+ ions are substituted by regenerating ions coming from the anodic compartment and are transferred into a receiver compartment at the cathodic side where they are concentrated. Cation-exchange textiles having strong or weak acid functional groups, sulfonic (SCET) and carboxylic (CCET), respectively, were used. Different regenerating ions, H +, Na +, K + and NH 4 + were investigated under various current densities. Electroregeneration ratios between 85% and 100% were obtained with sulfonic and carboxylic textiles previously loaded with Pb 2+ ions. In the continuous electroextraction, removal efficiencies higher than 95% were obtained with a 10 ppm Pb 2+ feed solution giving an outlet concentration of less than 1 ppm. The efficiency of the two textiles was compared in terms of mass transfer and energy consumption.