BOD vs COD difference?

BOD vs COD difference?

• A. BOD measures biodegradable organic matter; COD measures total oxidizable organics
• B. COD measures biodegradable organic matter; BOD measures total oxidizable organics
• C. BOD measures inorganic nutrients; COD measures dissolved salts
• D. BOD measures color; COD measures turbidity

Answer: (A)

BOD indicates the amount of biodegradable organic matter that microbes can oxidize in water, while COD indicates the total amount of organic matter that can be chemically oxidized. BOD is typically measured over several days (often five days, BOD5) to reflect the oxygen demand from microbial decomposition of biodegradable substances. COD, on the other hand, uses a strong chemical oxidant to quickly oxidize most organic compounds, giving a measure of the overall oxidizable organic load in a few hours. Because COD oxidizes both biodegradable and non-biodegradable organics, COD values are usually higher than or equal to BOD values for the same sample. That’s why the statement that BOD measures biodegradable organic matter and COD measures total oxidizable organics is correct. Inorganic nutrients and salts, or properties like color and turbidity, aren’t what these tests quantify; they specifically assess the oxygen-demand potential of organic matter, with COD providing a broader, faster estimate than BOD.

BOD indicates the amount of biodegradable organic matter that microbes can oxidize in water, while COD indicates the total amount of organic matter that can be chemically oxidized. BOD is typically measured over several days (often five days, BOD5) to reflect the oxygen demand from microbial decomposition of biodegradable substances. COD, on the other hand, uses a strong chemical oxidant to quickly oxidize most organic compounds, giving a measure of the overall oxidizable organic load in a few hours. Because COD oxidizes both biodegradable and non-biodegradable organics, COD values are usually higher than or equal to BOD values for the same sample. That’s why the statement that BOD measures biodegradable organic matter and COD measures total oxidizable organics is correct. Inorganic nutrients and salts, or properties like color and turbidity, aren’t what these tests quantify; they specifically assess the oxygen-demand potential of organic matter, with COD providing a broader, faster estimate than BOD.