Abstract: In a process for an electrochemical treatment of cellulose waste lye, mass transport takes place through a diaphragm or membrane between a cathode chamber and an anode chamber, and optionally through a middle chamber. Cationogenic components are removed from cellulose waste lye containing lignin sulfonates and being located in at least one of the chambers. Lignin sulfonic acids are produced from the waste lye. In an installation for an electrochemical treatment of cellulose waste lye, at least one diaphragm divides at least one reaction vessel into at least one cathode chamber and at least one anode chamber. At least one cathode electrode is disposed in the at least one cathode chamber, and at least one anode electrode is disposed in the at least one anode chamber. The at least one cathode electrode is formed of iron or aluminum and the at least one anode electrode is formed of special steel, in particular V4A steel.