A BOD test is conducted using standard size BOD bottles. The technician prepares  two BOD bottles on Day 0, putting 20 mL of wastewater into each bottle and then filling  each bottle the rest of the way with dilution water. A seed is also added. He measures the  dissolved oxygen concentration in the first bottle to be 8.2 mg/L. He places the second bottle  in the 20C incubator. Five days later, he measures the dissolved oxygen concentration in the  second bottle to be 3.4 mg/L. A control bottle (containing dilution water and seed) was also  tested and did not have an oxygen demand. a. What is the 5-day BOD for this waste? b. If the ultimate BOD of this waste is 130 mg/L, what is the BOD rate constant? c. If the test was re-run at 30C, find the 5-day BOD and ultimate BOD for this higher  temperature.

A 5-day BOD test if performed on an industrial wastewater sample that contains no bacteria; therefore, a "seeded" BOD test is run. Ten ml of "seed" are added to 20 liters of dilution water. Thirty milliliters of industrial wastewater are added to a 300-ml BOD bottle, and the remaining volume consists of "seeded" dilution water. The average dissolved-oxygen concentrations of the diluted wastewater samples and blanks (seeded dilution water) on the first day of the test were 7.5 mg/L and 9.0 mg/L, respectively. After incubation of separate BOD bottles at 20 C for 5 days, the average DO concentrations of the diluted wastewater BOD bottles and seeded dilution water BOD bottles were 3.1 and 8.5 mg/L, respectively. Calculate the 5-day BOD of the industrial wastewater. I am unsure of how to solve for f given this information, where f = (% seed in D1) / (% seed in B1)

A wastewater sample subjected to standard BOD5 test yields a test result of 200 mg/L. The rate constant is 0.18/day at 20°C (to the base 'e'). Another sample of the same wastewater is tested at a temperature of 30°C. The time in days after which the BOD yielded is 200 mg/L is (up to 2 decimal places).

For a BOD analysis, 30 ml of waste with a DO of zero mg/L, is mixed with 270 ml of dilution water with a DO of 9 mg/L. The sample is then put in an incubator. The final DO is measured after 7 d. The final DO is measured at 3.0 mg/L. However, it is discovered that the incubator was set at 30°C. Assume a k1 of 0.2 d–1 (base e) at 20°C and θ = 1.05. Determine the 5 d, 20°C BOD of the sample