The biological oxygen demand (BOD) of unpolluted river water is:
10 - 20 mg O₂/dm³/5 day.
5-10 mg O₂/dm³/5 day.
less than 5 mg O₂/dm³/5 day.
more than 20 mg O₂/dm³/5 day.
Answer is Wrong!
Answer is Right!
This question was previously asked in
UPSC Geoscientist – 2020
– It is measured over a specific period, usually 5 days (BOD₅) at a standard temperature (20°C).
– Lower BOD values indicate better water quality with less organic pollution.
– Moderately polluted water might have BOD values between 2 and 8 mg/L.
– Heavily polluted water can have BOD values exceeding 20 mg/L.
– The term dm³ is equivalent to a liter (1 dm³ = 1 L).