ELECTRODIALYSIS METHOD FOR PURIFYING OF SILICATE-CONTAINING POTASSIUM HYDROXIDE ETCHING SOLUTION

An electrodialysis method for the treatment of silicate-containing potassium hydroxide etching waste solution is provided. The method comprises: providing a reaction tank including a cathode, an anode, and two cation dialysis membranes, wherein the reaction tank is divided by the cation dialysis membranes into a cathode chamber, an anode chamber and a waste solution disposing chamber located therebetween; filling a sulfuric acid solution into the anode chamber; filling a potassium hydroxide solution into the cathode chamber; introducing a silicate-containing potassium hydroxide etching waste solution into the waste solution disposing chamber; and applying a voltage and a current density to each of the chambers to render potassium ions to transport from the waste solution chamber through the cation dialysis membrane to the cathode chamber.