A BOD test was conducted on the unchlorinated effluent of a municipal treatment plant. The wastewater portion added to a 300 mL BOD bottle was 8 ml. The dissolved oxygen values and incubation periods are listed below.
a. Determine the 5-day BOD value. (BODs = 178 ppm)
b. Given a rate constant of 0.2 day^-1, calculate the ultimate BOD.
c. Plot the theoretical vs. actual BOD vs. time on excel. The x-axis should be time and should go from 0 to 25 days. The actual data points should be represented by points while the theoretical BOD vs. time should be represented by a line. Please label both axes and provide a title for the graph.
| Bottle number |
Initial DP, mg/L |
Time, days |
Final DO,mg/L |
| 1 |
8.4 |
0 |
8.4 |
| 2 |
8.4 |
0 |
8.4 |
| 3 |
8.4 |
1 |
6.2 |
| 4 |
8.4 |
1 |
5.9 |
| 5 |
8.4 |
2 |
5.2 |
| 6 |
8.4 |
2 |
5.2 |
| 7 |
8.4 |
3 |
4.4 |
| 8 |
8.4 |
3 |
4.6 |
| 9 |
8.4 |
5 |
3.8 |
| 10 |
8.4 |
5 |
3.5 |