Patent ID: 8715504

Claim:
A process for removing sulfide from an alkaline sulfidic liquid, comprising: providing an electrolysis cell comprising a means for producing protons having an anode, a means for producing hydroxyl ions having a cathode, and an anion exchange membrane; subjecting the sulfidic liquid to electrolysis in said electrolysis cell, producing a sulfide-enriched concentrate at the anode side of said anion exchange membrane and a sulfide-reduced diluate at the cathode side of said anion exchange membrane, wherein the protons produced by said means for producing protons adjust the pH of the sulfide-enriched concentrate to between 6 and 10.5, and the hydroxyl ions produced by said means for producing hydroxyl ions adjust the pH of the sulfide-reduced diluate to at least 11; subjecting the sulfide-enriched concentrate to biological oxidation in a biological sulfide oxidation reactor; and recycling the sulfide-reduced diluate having a pH of at least 11 as an alkaline liquid.