METHOD FOR PURIFICATION OF WASHING WASTEWATER FROM HEXAVALENT CHROMIUM Russian patent published in 2023 - IPC C02F1/62 C02F1/28 C01G49/08 C02F101/22 

FIELD: washing wastewater purification.

SUBSTANCE: invention relates to the field of purification of washing wastewater from electroplating shops from heavy metals, which include chromium. Method for purification of washing wastewater from hexavalent chromium includes adding an adsorbent to wastewater, intensive mixing with water in a reactor with a stirrer for 25 minutes, subsequent settling and separation of solid and liquid phases. The adsorbent used is magnetite obtained by high-temperature reduction using waste carbon black and iron oxides contained in metallurgical dust at a ratio of CCr⁶⁺ : C_Fe3O4 = 1:6 mass parts. Settling of magnetite with adsorbed Cr³⁺ ions is carried out in a settling tank made of non-magnetic material, the outer side of the bottom of which is equipped with permanent magnets that accelerate the settling.

EFFECT: expansion of the range of iron oxide adsorbents for the treatment of washing wastewater from hexavalent chromium, mainly with a focus on secondary raw materials, as well as simplification of the technology for their production, which can lead to a reduction in the cost of treatment of washing wastewater from electroplating from hexavalent chromium without compromising the cleaning efficiency.

1 cl, 2 tbl