Chemical Oxygen Demand (COD) is a measure of
All organic matters in water
Chemical Oxygen Demand (COD) is an important water quality parameter used to assess the level of pollution in a water body.
COD measures the total amount of oxygen required to chemically oxidize ALL the organic matter present in a water sample - this includes both biodegradable organic matter (which microorganisms can break down) as well as non-biodegradable or refractory organic matter (which cannot be easily broken down biologically, such as certain industrial pollutants).
This is different from Biochemical Oxygen Demand (BOD), which only measures the oxygen consumed by microorganisms while decomposing biodegradable organic matter - BOD does not account for non-biodegradable organic compounds.
Because COD uses a strong chemical oxidizing agent (such as potassium dichromate) to oxidize organic matter, it captures a more complete picture of total organic pollution, covering both biodegradable and non-biodegradable fractions.
Therefore, "inorganic matters in water" is wrong since COD targets organic, not inorganic, matter; "all chemicals present in water" is too broad and incorrect; and "only some specific organic matters" is incomplete since COD covers ALL organic matter, not just specific ones.
The correct answer is that COD measures all organic matters in water.
Similar Questions
Give below are two statements:
Statement I : Thermal pollution, usually effluent from cooling systems of power plants or other industries, alters water temperature in a lake or stream.
Statement II : Humans also cause thermal pollution by altering vegetation cover and run-off patterns.
In the light of the above statements, choose the correct answer from the options given below:
Major contributor to carbon monoxide emissions in metropolitan areas of India is/are:
The most important pollutants that cause degradation of water quality in rivers and streams are
(a) Bacteria
(b) Nutrients
(c) Metals
(d) Total dissolved solids
(e) Algae
Choose the most appropriate answer from the options given below:The most dominant source of Benzene emissions in ambient air is
Major sources of oxygen demanding waste in fresh water systems are
(a) Agricultural run-off
(b) Food processing
(c) Ore mining
(d) Sewage effluent
(e) Landfill sites
Choose the correct option from those given below: -
Which of the following pollutant gases is not produced both naturally and as a result of industrial activity?
Which of the following pollutants is the major cause of respiratory diseases?
Assertion (A): In urban areas, smog episodes occur frequently in winters.
Reason (R): In winters, a lot of biomass is burnt by people for heating purposes or to keep themselves warm.
Choose the correct answer from the code given below:
With increase in temperature, the dissolved oxygen content in a water body will:
In the formation of Surface Ozone, which of the following do play an important role?
(a) Oxides of nitrogen
(b) Oxides of sulphur
(c) Sunlight
(d) Carbon monoxide
Choose the correct answer from the code given below:
Important Questions from Pollution
Which of the following isnota common component of photo-chemical smog?
Which of the following is NOT the main objective of Ganga action plan?
Which of the following pollutants causes water pollution ?
Presence of which pathogenic microbe in water is indication of contamination?
Which of the following isnota vehicular pollutant?
