A. Bone decay
B. Cancer
C. Asphyxiation (suffocation)
D. Anemia
A. Hydrocarbons
B. Hydrogen fluoride
C. Hydrogen sulphides
D. Nitrogen dioxide
A. Sludge disposal
B. Reduction of excessive flow in sewers
C. Biological treatment of wastes
D. None of these
A. 20
B. 100
C. 400
D. 200
A. HF
B. SO2
C. H2S
D. Both B. & C.
A. Dissolved oxygen content
B. Biological oxygen demand
C. Vapor pressure
D. All A., B. and C.
A. Turbidity
B. Caustic embrittlement
C. Suspended silica
D. Dissolved oxygen