Method of Removing Hexacyanoferrate From Waste Water
Original Publication Date: 1988-Jul-01
Included in the Prior Art Database: 2005-Feb-15
Industrial waste water containing K3[Fe(CN)6] and K4[Fe(CN)6] is detoxicated by pouring the waste water into a solution containing heavy metal ions in an overstoichiometric amount for precipitating the respective hexacyanoferrates. The method comprises providing a solution containing heavy metal ions in excess of the amount necessary for quantitatively precipitating the hexacyanoferrates in a predetermined quantity of waste water, setting the pH value to between 3 and 4, adding the waste water, adding appropriate filtering means, allowing the mixture to react for about 15 minutes, and filtering. Subsequently, no sizeable amounts of colloidal ferrous hexacyanoferrate or free cyanide are detectable in the filtrate.