by Derek Pletcher
The need to protect the environment from further contamination by transition and heavy metal ions is well established and universally reinforced by legislation which sets limits on the levels in effluents which may be discharged into sewers and local waters. All chemical plants, factories and other facilities employing solutions of such metals should therefore be treating their wastewater before discharge. Electrochemical methods compete with a number of other technologies including evaporation, precipitation, ion exchange and solvent extraction to offer solutions to the needs of the many industries involved.
Electrochemical methods, however, are uniquely capable of recovering pure metal for recycle. Although electrochemical technology for metal ion removal has been available for some time [1-3], it continues to develop to meet the challenges of lower consent levels and more complex effluent compositions. Moreover, the technology now on the market is based on diverse electrochemical concepts.