METHOD OF TREATING WASTE WATER FROM AMMONIUM IONS Russian patent published in 2020 - IPC C02F1/58 C02F101/16 

FIELD: technological processes.

SUBSTANCE: invention can be used for waste water treatment at chemical, petrochemical, metallurgical and coke-chemical industry. Waste water treatment from ammonium ions involves addition of solutions containing phosphate ions and magnesium ions into waste water and magnesium-ammonium phosphate deposition while stirring in an alkaline medium. Prior to deposition of magnesium-ammonium phosphate into the solution of phosphoric acid, calcined soda is introduced, and waste water is introduced into the formed solution. Produced carbon dioxide is blown with air, then the obtained decarbonized solution is added to waste water, a solution containing magnesium ions and a sodium hydroxide solution are added to them. Molar ratio of calcined soda to phosphoric acid 2Na:HPO₄ is required to form sodium hydrophosphate Na₂HPO₄. Precipitated magnesium-ammonium phosphate is separated from water and purified water is discharged.

EFFECT: disclosed invention provides reduced consumption of sodium hydroxide at the step of depositing magnesium-ammonium phosphate.

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