COMPLEX OF DOMESTIC SEWAGE TREATMENT FACILITIES Russian patent published in 2002 - IPC

FIELD: treatment of sewage and biological purification of waste water followed by tertiary treatment through filtration; treatment of waste water at low flow rate and at increasing flow rate at different degree of contamination. SUBSTANCE: proposed complex includes, grate, sand trap, settler-balancing reservoir, aerotank unit and biological ponds made in form of multi-sectional biological pond. Besides that, complex includes biosorption filter filled with mixture of inert coarse-dispersed material by 50%, for example, gravel: fractions of 1 to 5 mm, 30 %: fractions of 5 to 15 mm, 50% and fractions of 15 to 25 mm, 20%, biosubstrate on base of waste bark, for example, softwood disbarking of size 10 to 100 mm, 70%; sawdust, 20% and excessive activated sludge, 10 %. Filter is provided with perforated pipes mounted below freezing level. Biofilter surface is planted with Salix alba. Cat-tail and reed are planted on banks of multisectional biopond. Eichornia crassipes are planted in pond proper. Filtering dams are provided between sections of biopond; floating aerator is mounted in first section. Filtering dams have non-filtering bases made from waterproofing soil, for example clay at distance of 0.75 from normal headwater level and filtering crest made from inert coarse-dispersed materials, for example gravel. EFFECT: enhanced efficiency of sewage treatment; improved quality of stable purification at dynamic change in flow rate and degree of contamination. 4 cl, 2 dwg