METHOD FOR WATER PURIFICATION FROM COMPLEX COMPOUNDS OF HEAVY METALS Russian patent published in 2021 - IPC C02F9/04 C02F1/62 C02F101/20 C02F103/06 C02F103/16 

FIELD: water treatment.

SUBSTANCE: invention discloses a method for water purification from complex compounds of heavy metals, including the conversion of complex compounds of metals into a cationic form, the formation and removal of insoluble hydroxides and subsequent deep purification. The method is characterized by the fact that the transfer of complex compounds of metals is carried out by lowering the pH level to values not higher than 3.5 by adding acid. Then iron salts are introduced, which play the role of a coagulant and an electron donor, in the amount required to destroy the complex and create coagulating flocs, then the pH is increased to values determined depending on the metals present in the source water, and the resulting suspensions are removed by precipitation or by filtration, after which the clarified water is passed through a layer of granular catalyst, which increases the alkalinity of the passed water, ensuring the simultaneous passage in the intergranular space of the processes of formation of insoluble hydroxides and their precipitation on catalyst grains having negative ζ-potential of the surface, and the formed precipitate is removed by washing the granular catalyst with water to create a boiling bed in which the precipitate is separated from the catalyst surface as a result of friction between the grains.

EFFECT: invention is aimed at increasing efficiency of cleaning, as well as increasing process safety, reducing the cost of equipment and operation, providing possibility of organizing a closed cycle of water use.

1 cl, 6 tb,l 4 ex