METHOD OF AEROBIC BIOLOGICAL PURIFICATION OF SEWAGE WATERS Russian patent published in 2014 - IPC C02F3/00 C02F3/02 

FIELD: chemistry.

SUBSTANCE: claimed is a method of aerobic biological purification of sewage waters. The method includes settling sewage water in a primary settler and separation of a raw sediment from it, aerobic biological purification of sewage water by active sludge in an aerotank, settling the mixture of sewage water and the active sludge in a secondary settler, output of the precipitated active sludge from the secondary settler, supply of the return active sludge into the aerotank for participation in the biological process of oxidation, output of the excessive active sludge from the secondary settler and discharge of purified water from the purification installation. Excessive sludge is subjected to a hydromechanical impact with an intensity of 500-3000 J/kg of the microbial mass × s, 70-80% of the processed active sludge are mixed with initial sewage water before supplying it to the primary settler, and 20-30% - with the mixture of sewage water and the active sludge, discharged from the aerotank, before supplying it into the secondary settler. Processes of mixing the said suspensions are carried out for 10-20 min with an intensity, corresponding to the dimensionless Reynolds number Re=2000-4000.

EFFECT: invention makes it possible to increase the quality of purified sewage water, reduce the output of the excessive active sludge from the purification installations.

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