METHOD OF EXTRACTING CHROMIUM (III) AND (VI) FROM INDUSTRIAL WASTE WATER Russian patent published in 2024 - IPC C02F1/62 C02F1/32 

FIELD: water treatment.

SUBSTANCE: invention relates to treatment of industrial waste water from heavy metals, particularly from chromium (III) and (VI) compounds. Method of extracting chromium (III) and (VI) from industrial waste water involves treating the solution with an inorganic sorbent based on titanium dioxide when exposed to electromagnetic radiation, followed by separation of TiO₂. Solution is preliminarily brought to pH 3, complexing agent Trilon B is added in molar ratio Trilon B:Cr – 2:1, mechanically activated with TiO₂ in concentration of 1 g/l, illuminated with a light-emitting diode with wavelength of not more than 400 nm while stirring with a magnetic stirrer for one hour, TiO₂ is removed by centrifugation. Further, 30% NaOH solution is added to the solution until pH ≥ 12.5, illuminated with ultraviolet light for one hour and removed by vacuum filtration through a membrane with pore diameter of 0.1 mcm.

EFFECT: method increases degree of purification of waste water from heavy metals, particularly from chromium (III) and (VI) compounds.

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