Process of removing cyanide from waste water
OwnerXinyu Yanginventor
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Abstract
A process for removing cyanide from liquid waste by electrolysis is disclosed. The method includes combining waste water and NaCl to an electrolyser cell, the cell having positive and negative electrode plates. The NaCl concentration in the cell is maintained at about 180 g/l. HCl and NaOH are added to maintain the pH at about 10.5. The liquids are agitated, and a current is applied to the electrode plates. The cyanide is decomposed, and the heavy metals are separated out. The waste gasses are sent through a purifying tower where CO.sub.2 and N.sub.2 are released. A decyanation apparatus comprising an electrolyser and a gas purifier is also disclosed.
Claims8
A process for removing cyanide from liquid waste by electrolysis comprising the steps of:
- adding liquid waste containing cyanide to an electrolyser cell;
- maintaining a pH of said liquid waste at about 10.5;
- adding NaCl into said electrolyser cell in a manner that a NaCl/liquid waste radio is controlled to about 0.5-3 g/l;
- agitating the liquid in said electrolyser cell;
- applying a high density current to a set of positive and negative electrode plates defining an anode and a cathode respectively in said electrolyser cell;
- monitoring an equivalent potential of chlorine and cyanogen of the liquid in the electrolyser cell;
- discharging treated liquid from the electrolyser cell when a potential of the liquid approaches a selected value;
- and
- conveying waste gases consisting essentially of HCN and CNCl produced in the electrolysis to a purifying tower and purifying said gases therein.
Dependencies are inferred from the claim text.