Method for electrochemical treatment of effluents, especially effluents from leather tanneries, comprising chromium salts

摘要

The present invention relates to a method for treating effluents, especially the effluents from leather tanneries, containing chrome salts, i.e. the salts of chromium having a (III) oxidation degree, characterized in that the supplied effluents or those having a pH that is lower than 6 undergo an electrochemical reaction in a reactor comprising an anode and a cathode in such a way that the chromium having a (III) oxidation degree is transformed into chrome having a (VI) oxidation degree, and in that the treated effluents are recovered. The treatment method is followed in an advantageous manner by a method for recovering the hexavalent chromium by means of selective extraction in an appropriate solvent medium followed by reduction of the hexavalent chromium into trivalent chromium.