Monday, November 30, 2009
Wednesday, November 11, 2009
F/M: Food to Microorganism Ratio
- Influent Flow into your activated sludge system (Flow MGD)
- Influent CBOD (mg/l) concentration into your aeration tank.
- Mixed Liquor Volatile Suspended Solids Concentration (mg/l)
- Volume (in gallons) of your aeration system
The term Food to Microorganism Ratio (F/M) is actually a measurement of the amount of incoming food ( Lbs of Influent CBOD) divided by the Lbs of Microorganisms in your system. Some calculations also include the volume of activated sludge in your clarifiers, the one demonstrated here does not. If you have an activated sludge system, you should determine your F/M ratio regularly.
To determine the amount of incoming food (F), you need to know the CBOD of the influent into your activated sludge(aeration) system. You also need to know the flow(MGD). So to calculate the amount of food we do the following calculation:
F= Influent Flow (MGD) X Influent CBOD Concentration (mg/l) X 8.34
To determine the volume of microorganisms (M), you need to know the volume of your aeration system and you need to know the concentration of Volatile Solids in your aeration system (MLVSS) or Mixed Liquor Volatile Suspended Solids. To calculate the microorganisms, we do the following calculation:
M= Aeration System Volume (in Millions of Gallons) X MLVSS X 8.34
To Calculate the Ratio: F/M
Example:
Facility Flow = 1.2 MGD Influent CBOD= 230 mg/l
1.2 X 230 X 8.34 = 2301.84 Lbs Coming In
F= 2301
Aeration System Volume 250,000 gal / 1,000,000 = 0.25MG
MLVSS = 2500mg/l
0.25 X 2500 X 8.34 = 5215 Lbs of Microorganisms under Aeration
M = 5212
2301/5212 = 0.44 F/M Ratio
info from Pennsylvania Dept of Environmental Protection
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Tuesday, November 10, 2009
Regional Water Board public workshop tonight
Agricultural Services Building
5630 South Broadway Eureka, CA
November 10, 2009
6:30 – 8:30 pm
Available documents pertaining to the Elk River TMDL may be viewed and downloaded here
Documents include:
•A variety of available documents pertinent to the development of the Elk River Sediment TMDL; and
•Instructions regarding how to sign-up for mailing lists to receive future notifications relating to the Elk River Sediment TMDL.
Contact information:
Adona White
5550 Skylane Blvd., Suite A
Santa Rosa, CA 95403
(707) 576-2672
AWhite@waterboards.ca.gov
note:
The North Coast Regional Water Quality Control Board (Regional Water Board) and the U.S. Environmental Protection Agency (EPA) have listed the Elk River watershed under the Clean Water Act Section 303(d) as a sediment impaired waterbody. A program has been developed to recover 303(d) List waterbodies via the establishment of Total Maximum Daily Loads (TMDL). At this time, the Regional Water Board staff is in the process of establishing a TMDL for sediment in the Elk River watershed. The goal of the TMDL program is to restore and maintain the sediment impaired beneficial uses of water of Elk River and its tributaries. Staff will develop the technical TMDL, the implementation, and monitoring plans together.
Sunday, November 8, 2009
Tuesday, October 27, 2009
Monday, October 19, 2009
Anaerobic Digesters Schematic
Wednesday, October 14, 2009
Parshall Flume
Father of the Flume Ralph L. Parshall was a pioneer in the fields of civil engineering and hydrology, Parshall is best known for developing the Parshall Flume at the then-named Colorado Agricultural College's hydrology lab in 1921 (CSU)
Tuesday, October 13, 2009
Get with the Flow: discussion on Humboldt water
All meetings 6-8:30pm
- Oct 13 - Azalea Hall, McKinleyville
- Oct 14 - D St. Neighborhood Center, Arcata,
- Oct 22 - Warfinger Building, Eureka