Patent ID: 8088266

Claim:
An electrodialysis method for the treatment of a silicate-containing potassium hydroxide etching waste solution, comprising: 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 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 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, and to control the mole ratio of silicon dioxide and potassium oxide in the waste solution chamber to be less than 10.