Physico-Chemical Effluent Treatment

Development of a modified method of electro dialysis for selective metal take off from liquid waste

Electrodialysis is a successful process for single-component metal solutions. No problems are associated with the further treatment of detoxified wastewater in conventional purification plants. However, using membrane materials currently available, this process cannot be applied to solutions containing a number of metals. 

 

Summary

The disposal of liquid hazardous wastes from the electroplating industry has long been a key consideration in the development of new water and wastewater treatment processes.  Ecological factors and economic considerations are key aspects of this issue.

In this connection, a modified electrodialysis process has been developed and tested in the course of this project.  This process is based upon the concept of the selective separation of metals from galvanic semiconcentrates for the purposes of metal recovery, the substantial removal of heavy metals from wastewater and the additional treatment of the detoxified semiconcentrate in conventional rinsing water purification plants.  To this end, three electrodialysis modules have been produced for laboratory use and trial operation, and have been tested using various metal solutions.

Results:

This process can be successfully applied to single-component metal solutions.  In this case, the concentration of metal in the wastewater can be significantly reduced.  The volume of filtered concentrate is also reduced, and can be subject to special treatment on a more cost-effective and efficient basis.

This process is not suitable for solutions which contain a number of metals.  The mutual interaction and interference of the individual detoxification stages is such that the selective removal of specific metals cannot be achieved.

Project Participants

Implementing Institution

IfU GmbH Privates Institut für Analytik

More Project Informations

Project title:  Development of a modified method of electro dialysis for selective metal take off from liquid waste

Project number:  02WA9739/0

Project period:  1997 - 1999

Project region:  Germany (Baden-Württemberg)

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Source: German National Library of Science and Technology Hannover (TIB)