WATER TREATMENT PROCESS Russian patent published in 1998 - IPC

FIELD: water treatment. SUBSTANCE: invention is intended to chemically treat water containing large amounts of fluoride. Sediment resulting from coagulation treatment of water is treated with hydrofluoric acid to give ashes that is controlled by potentiometric or conductometric. Insoluble residue is separated by mechanical filtration. Filtrate sol is further used for coagulation of water involving fluoridation, and solid residue is used in manufacture of building materials. Method enables isolation of natural fluoride from water for fluoridation of fluoride- deficient water, whereas coagulant is reused for peptization of metal hydroxide sediment. EFFECT: reduced reagent intake and simplified process. 1 dwg, 8 tbl