Step by step in preparation of BOD using DO probe

Step by step:

1. Preparation of Dilution Water
2. Preparation of BOD bottles
3. Read the dissolved oxygen content in the five BOD bottles using a dissolved oxygen probe. Ensure that no water is lost from the BOD bottles. Replace the stoppers without trapping any air.
4. Place the BOD bottles in the incubator. To prevent oxygen from leaking into the bottles during the incubation period, fill the portion of the bottle around the stopper with water using a squeeze bottle. It is the responsibility of the laboratory group to ensure that the water seal on the BOD bottles is maintained by checking each day and replenishing as required using a squeeze bottle of distilled water.
5. Following 5 days, remove the BOD bottles from the incubator and determine the dissolved oxygen concentration of each.
6. Compute the BOD using the following formula

BOD mgL= [(Initial DO-Final DO) x 300mL] / mL sample

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BOD procedure

Bod method

link to YSI 5000 manual

• avoid using detergents to clean the bod bottles
• use chlorine/bleach to clean it, to disinfects any microbes