Replenishment of dissolved oxygen in water stream polluted with industrial waste occurs by
A. Natural aeration of water stream
B. Photosynthetic action of algae
C. Both A & B
D. Neither A nor B
Answer: Option C
A. Natural aeration of water stream
B. Photosynthetic action of algae
C. Both A & B
D. Neither A nor B
Answer: Option C
Fluorosis is caused due to the presence of excessive amount of __________ in drinking water.
A. Mercury
B. Lead
C. Fluoride
D. Arsenic
Smog is not formed due to the presence of __________ in the atmosphere.
A. SO2
B. NOx
C. CO2
D. Any of these
Dose of chlorine for disinfection of water is about __________ mg/litre of water.
A. 0.01
B. 0.1
C. 0.3
D. 1
Join The Discussion