METHOD OF ELECTROLYTIC TREATMENT AND UNIT THEREFOR

摘要

An electrolytic treatment method and a unit in which such a method is practiced are provided wherein heavy metal hydrous oxides are precipitated and recovered from a dilute waste stream to render the waste stream suitable for discharge. The waste stream is passed into the cathode chamber of an anion exchange membrane delineated electrolytic cell and subjected to high current density electrolysis to promote the formation of regular, noncompressible metal hydrous oxide crystals. Fluoride ion is added to the precipitate-containing waste stream, the precipitate is filtered and the clarified liquid waste stream is split so that a portion is discharged and a portion is recycled into the metal ion-containing waste stream for further treatment.