Final answer:
The 5-day biochemical oxygen demand (BOD5) is a measure of the amount of oxygen required by aerobic bacteria to decompose organic matter in water over a 5-day period. It is calculated by subtracting the final dissolved oxygen content from the initial dissolved oxygen content of the waste water.
Step-by-step explanation:
The 5-day biochemical oxygen demand (BOD5) is a measure of the amount of oxygen required by aerobic bacteria to decompose the organic matter in water over a 5-day period. It is an important parameter used to determine the pollution level in water bodies.
To calculate the BOD5, you will need the information for the seeded dilution water and the BOD bottle containing the waste water. The test involves measuring the dissolved oxygen content in both samples and then subtracting the final dissolved oxygen content from the initial dissolved oxygen content of the waste water.
For example, if the initial dissolved oxygen content of the waste water is 8 mg/L and the final dissolved oxygen content after 5 days is 2 mg/L, the BOD5 would be 8 mg/L - 2 mg/L = 6 mg/L.