Method of continuously removing and obtaining ethylene diamine tetraacetic acid (EDTA) from the process water of electroless copper plating.

摘要

The invention relates to a method of continuously removing and obtaining ethylene diamine tetraacetic acid (EDTA) from the process water of electroless copper plating. For that purpose the process water containing the EDTA is directed into an electrodialysis cell alternatingly equipped with bipolar membranes and anion exchange membranes and/or cation exchange membranes, and to which a potential difference is applied. The EDTA is converted into its charge-neutral form by means of protonation, and the protons required for that purpose are generated via bipolar membranes through electrodialysis. The required pH-value is adjusted by a pH-controlled electric field regulation via the bipolar membranes.