| 摘要 |
<p>1325321 Treating sewage UNION CARBIDE CORP 1 July 1970 [2 July 1969] 31855/70 Heading C1C A method for treating waste water having a Biochemical Oxygen Demand (BOD) by aeration in contact with a bacterially active sludge having a volatile suspended solids to total suspended solids mass ratio of at least 0À55 which includes concentrating solids from the aeration and recycling concentrated solid to the aeration zone as said sludge, comprises introducing into an oxygenation zone waste water having a BOD, biologically active sludge having 12,000 to 50,000 ppm. total suspended solids content and feed gas comprising at least 50% oxygen (by volume) in sufficient relative quantities to provide mixed liquor of 4000 to 12,000 ppm. total suspended solids content and gas above said mixed liquor having an oxygen partial pressure of at least 300 mm. Hg in said oxygenation zone, and mixing said components in said zone for 20 to 180 minutes to form oxygenated liquor having a dissolved oxygen content (DO) of at least 3 ppm., with the day average food/biomass weight ratio (BODs/ Volatile Suspended Solids) for said liquor during the oxygen gas mixing being maintained at least at 0À15, separating said oxygenated liquor into said sludge and clarified effluent; and recycling at least part of said sludge to said oxygenation zone at flow rate relative to that of said waste water having a BOD such that the recycling sludge/waste water having a BOD volume ratio is 0À1 to 0À5.</p> |
