PROCESS WATER TREATMENT METHOD Russian patent published in 2003 - IPC

FIELD: waste water treatment. SUBSTANCE: treatment of metal ions-containing process water is combined with bleaching of lignocellulose pulp. Process includes following stages: regulating Mg(II) ion content to give flocculating base for metals and organics; introducing carbonate ion source into process water to precipitate calcium; raising pH value of process water by adding alkali solution such as metal hydroxide solution to precipitated metal compounds; adding flocculating reagent to process water; and flotation- mediated isolation of flocculated metal compounds from process water. EFFECT: simplified process due to enabled regeneration of reagents, accelerated flotation, and avoided use of antifoam reagents. 10 cl, 2 dwg