ADDITION OF ALUMINIUM REAGENTS TO OXYANION-CONTAINING WATER STREAMS Russian patent published in 2019 - IPC C02F1/58 C02F1/52 C02F5/06 C02F101/10 C02F103/06 

FIELD: chemistry.

SUBSTANCE: inventions can be used in processing and beneficiation of minerals, in construction, in cleaning of drainage, filtration and waste water. Method of removing oxyanions from an aqueous stream having a time-varying concentration of oxyanions and a metal cation involves continuous monitoring of metal cation concentrations and an oxyanion to provide data on the current concentration of said metal cation and the current concentration of the oxyanion. A source of an alkali-earth metal cation and an aluminium reagent are added to the aqueous stream based on the measured current concentrations of the metal and oxyanion cations to form a residue with an oxyanion. System for purification of water stream from oxyanion includes sources of agent containing metal cations and aluminium reagent, sensors for measurement of concentration and analysis of their change, controller made with possibility to control addition of reagents, at residue formation.

EFFECT: amount of metal cation and aluminium reagent added to flow are effective for formation of residue with oxyanion in ettringite-stoichiometric ratio and reduction of concentration of oxyanion in water flow below target threshold.

40 cl, 9 dwg, 3 tbl, 7 ex