Method of processing cyanide ions by ozone

摘要

A method is provided for decomposing free cyanide ion and metallic cyano complex ions in a liquid, comprising the steps of bringing the liquid into contact with ozone gas in a counterflow relation in the condition that the pH of the liquid is at least 10 with the mass flow rate of the ozone in the ozone gas up to 20 mg per minute per liter of liquid, and then bringing the liquid into contact in a counterflow relation with ozone gas having an ozone concentration of at least 150 g/m3 in the condition that the pH of the liquid is 7.0 to 9.5.