OLS : Record


Main Title Alum Addition and Step-Feed Studies in Oxygen-Activated Sludge.
Author Bishop, Dolloff F.; Heidman, James A.; Brenner, Richard C.; Stamberg., John B.;
CORP Author District of Columbia Dept. of Environmental Services, Washington. EPA-DC Pilot Plant.;Municipal Environmental Research Lab., Cincinnati, Ohio.
Year Published 1977
Report Number EPA-68-01-0162; EPA/600/2-77/166;
Stock Number PB-272 892
Subjects Alums; Activated sludge process; Oxygenation; Sewage treatment; Sedimentation; Liquid oxygen; Aluminum sulfate; Calcium oxides; pH; Clarifiers; Biochemical oxygen demand;
Library   Call Number Additional Info Location Date Modified
NTIS PB-272 892 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 06/23/1988
Collation 43p
Abstract A plug flow, O2-activated sludge process was operated with alum addition to remove phosphorus and with lime addition to prevent the process pH from decreasing below 6.4. The O2 reactor was operated at F/M ratios between 0.18 to 0.24 gm of BOD5/gm of MLVSS/day in a typical co-current O2-liquid contacting system. The alum dosages for the five steady-state operating periods increased from 84 mg/l to 184 mg/l was used to maintain the process pH at 6.4. The pollutant removals from the primary effluent ranged from 82 to 92% for BOD5 (7.4 to 19 mg/l of residual BOD5) and from 54 to 86% for phosphorus (1.05 to 3.26 mg/l of residual P). The optimum P removal occurred at a 1.8 to 1 average Al/P mole ratio with an average total residual P of 1.05 mg/l. In a second study, the O2 process was operated in a step-feed configuration consisting of a sludge oxygenation stage followed by three stages of oxygen aeration with equal portions of the primary effluent fed to each stage. In typical operation, the process with a F/M ratio of 0.23 exhibited a MLSS concentration profile in the four stages of 10,700 mg/l; 7,060 mg/l; 5,020 mg/l; and 4,150 mg/l. The step configuration clearly reduced the solids loading to the clarifier and provided an average MLSS of more than 6,500 mg/l. The step operation produced excellent BOD5 removals (89% from primary). The O2 usage in the step configuration was significantly less than the 90% typically achieved in co-current contacting.
NTIS Title Notes Final rept. Oct 72-Oct 73.
PUB Date Free Form Sep 77
Category Codes 13B; 68D
NTIS Prices PC A03/MF A01
Primary Description 600/14
Document Type NT
Control Number 323726232
Cataloging Source NTIS/MT
Origin NTIS
Type CAT