Q1: What does high COD to BOD ratio of an organic pollutant represent ?

ANS:A - High biodegradability of the pollutant

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.