tailieunhanh - Q13064 - INFO: BOD Manager Example Calculations

The method consists of filling an airtight bottle with a sample. The bottle is a specified size and filled to overflowing. The sample is incubated at constant temperature for five days. Dissolved oxygen (.) is measured by probe before and after incubation. BOD is computed based on the difference between initial and final . | Print Article Page 1 of 4 Q13064 - INFO BOD Manager Example Calculations Close Window Article ID Q13064 Created Date 6 22 2010 9 48 AM Last Modified 6 22 2010 9 48 AM Author Scott Dorner Original URL http instantkb id 13064 BOD Example Calculations The method consists of filling an airtight bottle with a sample. The bottle is a specified size and filled to overflowing. The sample is incubated at constant temperature for five days. Dissolved oxygen . is measured by probe before and after incubation. BOD is computed based on the difference between initial and final . The test uses dilution water and a known amount of sample in a 250-300 ml incubation bottle. A small amount of seed is added to samples where microbial activity may not be present. The initial . is measured by probe and the bottle is stored at 20 C. After five days final . is measured. If no seed is used the BOD of the bottle is computed using Equation 1. BOD IDO - FDO Eq. 1 VS VB where IDO initial . of diluted sample mg L FDO final . of diluted sample mg L VS volume of sample ml VB volume of bottle ml BOD biochemical oxygen demand mg L When seed is added seed control tests must be done to determine the amount of oxygen depleted by the seed. Calculation of BOD includes a correction factor for seed as expressed by Equation 2. BOD IDO - FDO - Cavg SV Eq. 2 VS VB where IDO initial . of diluted sample mg L FDO final . of diluted sample 0 mg L VS volume of sample ml VB volume of bottle ml Cavg correction factor for oxygen depletion resulting from presence of seed SV Volume of Seed added to Sample in ml. http instantkb id 13064 3 16 2011 Print Article Page 2 of 4 BOD biochemical oxygen demand mg L The correction factor for a bottle of Seed is derived using Equation 3. C ISDO - FSDO Eq. 3 VN where C correction factor for oxygen depletion resulting from presence of seed ISDO initial . for seed control test N FSDO final . for seed