METHOD OF PURIFYING WATER FROM HEAVY METALS, COLLOID SYSTEM FOR WATER PURIFICATION, AND METHOD OF PREPARATION THEREOF Russian patent published in 1996 - IPC

FIELD: water purification. SUBSTANCE: invention relates to purifying water in electroplating and leather industries. Method prescribes treating water with 1-10 ml of a colloid system per 1 l of water at pH 8.0-9.2, the water-based colloid system containing 0.3-1.3 wt % ferric hydroxide, 3.2-6.4 wt % ferrous hydroxide, and 0.3-1.0 wt % alkali metal chloride. Colloid system is an electrogenerated suspension, which, when stored for a long time, may be stabilized with 0.1-1.2% of a substance selected from the group including naturally occurring or synthetic aluminosilicates, calcium ortophosphate, and also inorganic and organic polyelectrolytes. Suspension is characterized by particle size 5-15 mcm, specific surface 100-250 sq.m/g, and density 1.05-1.1 g/cu.cm. Colloid system is prepared by electrochemical dissolution of iron anodes in aqueous solution having electroconductivity no lower than 3 x 3•10^-3 om^-1 cm^-1 under periodical blowing with air until 10-20% of dissolved iron is transferred into ferric form. EFFECT: improved procedure. 11 cl, 1 tbl