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 |
Additional Subjects |
Alums ;
Activated sludge process ;
Oxygenation ;
Sewage treatment ;
Sedimentation ;
Liquid oxygen ;
Aluminum sulfate ;
Calcium oxides ;
pH ;
Clarifiers ;
Biochemical oxygen demand ;
|
Holdings |
Library |
Call Number |
Additional Info |
Location |
Last Modified |
Checkout Status |
NTIS |
PB-272 892 |
Some EPA libraries have a fiche copy filed under the call number shown. |
|
07/26/2022 |
|
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 |
Cataloging Source |
NTIS/MT |
Control Number |
323726232 |
Origin |
NTIS |
Type |
CAT |