METHOD OF PURIFYING AQUEOUS SOLUTIONS FROM ARSENIC AND CONCOMITANT HEAVY METALS Russian patent published in 2010 - IPC C02F1/62 C02F101/20 C02F103/16 

FIELD: chemistry.

SUBSTANCE: invention relates to methods of purifying waste water and other aqueous acidic solutions containing arsenic and heavy metals: chromium, manganese, iron, nickel, copper, zinc, strontium, cadmium and lead and can be used in chemical, metallurgical, mechanical and other industries, having toxic water containing the said metals in concentration exceeding the maximum permissible concentration value. Aqueous solutions are treated in two steps with removal of the residue formed after each step. At the first step precipitation is carried out with iron ions and then oxidation, subsequently bringing the level pH to 6.5-7.0, and at the second step precipitation is carried out with ferric ions, subsequently bringing the pH level to 10.0-10.5.

EFFECT: invention increases efficiency of removing arsenic and concomitant metals from waste water in form of insoluble compounds and bringing concentration of the metals and arsenic in the purified water to values below their maximum permissible values.

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