Civil Engineering - UPSC Civil Service Exam Questions - Discussion

Option B is correct.

So, BOD/COD = 0.6.

As per GATE 2006, Low COD to BOD ratio of an organic pollutant represents the High biodegradability of the pollutant.

* BOD (Biochemical oxygen demand) - The amount of oxygen required by micro-organisms to degrade the organic matter.
* COD (Chemical Oxygen Demand) - In this process, Use a strong chemical agent (such as potassium dichromate) is used to degrade both the organic as well as inorganic matter present in the wastewater samples.

* COD values are always higher than the BOD values. Because COD includes both biodegradable and non-biodegradable substances whereas BOD contains only bio-degradable.

I believe that A is the answer. What makes the COD to BOD ratio high is that technically the value of BOD is expected to be less than the COD. Less BOD means high Dissolved Oxygen. This high amount of dissolved oxygen is said to be directly proportional with expected amount of microorganisms that will degrade the organic.

Since the ratio is high it means bod, demand is low, in other biochemical oxygen is present in excess, therefore there ll be high biodegradability of pollutant.

Hence option A is correct.

Answer B is correct.

The answer is B.

If answer A it means bod will be close to cod so the ratio will near to 1.

Answer:B (low biodegradability of the pollutants).

BOD (Biochemical oxyen demand) - The amount of oxygen required by micro-organisms to degrade the organic matter.

COD (Chemical Oxygen Demnad) - In this process, Use of strong chemical agent (such as potassium dichromate) is used to degrade both the organic as well as inorganic matter present in the wastewater samples.

COD values are always higher than the BOD values. Because COD includes both biodegradable and non-biodegradable substances whereas BOD contains only bio-degradable.

The correct Answer is B.

B is correct, non-bio-degradable will be more.

Option B is correct.