Looking for classes? Ksquare Career Institute, Bengaluru →
Limit of BOD prescribed by Central Pollution Control Board for the discharge of industrial and municipal waste waters into natural surface waters, is -
A
$\lt$ 3.0 ppm
B
$\lt$ 10 ppm
C
$\lt$ 100 ppm
D
$\lt$ 30 ppm
Detailed Solution
BOD (biochemical oxygen demand) is the amount of oxygen required by micro-organisms to oxidise the organic matter present in one litre of water; it is a measure of organic pollution.
Effluents with a high BOD use up the dissolved oxygen of the receiving water and kill the aquatic life.
So waste water must be treated to bring down its BOD before it is released into rivers and lakes.
The Central Pollution Control Board (CPCB) has prescribed that the BOD of industrial and municipal waste water discharged into natural surface waters should be less than 30 ppm (30 mg/L).
Clean water has a BOD of less than about 5 ppm, while untreated sewage has a BOD of a few hundred ppm.
So the prescribed limit is less than 30 ppm.
Effluents with a high BOD use up the dissolved oxygen of the receiving water and kill the aquatic life.
So waste water must be treated to bring down its BOD before it is released into rivers and lakes.
The Central Pollution Control Board (CPCB) has prescribed that the BOD of industrial and municipal waste water discharged into natural surface waters should be less than 30 ppm (30 mg/L).
Clean water has a BOD of less than about 5 ppm, while untreated sewage has a BOD of a few hundred ppm.
So the prescribed limit is less than 30 ppm.