METHOD OF PURIFICATION OF LOW-CLOUDY COLOR WATERS Russian patent published in 2003 - IPC

FIELD: economic-drinking water supply; purification and sanitation of the surface water sources. SUBSTANCE: invention relates to the methods of water purification and sanitation in the surface water sources by treatment with a aluminum- bearing coagulant and the subsequent water clarification by filtration and may be used predominantly in the field of economic - drinking water supply, in particular at purification and sanitation of the low- cloudy color waters. The invention provides, that at two-stage treatment of the low-cloudy color water with a aluminum- bearing coagulant and introduction at the first stage of a deficient dose of aluminum sulfate with subsequent clarification of the water by filtration, at the second stage the water is added with aluminum oxychloride at the ratio 1 : (4-5) by Al₂O₃ in respect to the amount before injected aluminum sulfate, and the total amount of injected aluminum-bearing coagulants is determined from a relationship: where D_c is the total amount of a coagulant, mg/l; Col is the color of the clarified water, degrees. EFFECT: invention providing high degree water purification allows to reduce consumption of the coagulant at simultaneous increase of duration of the filtration cycle. 2 tbl