Presence of dissolved impurities of ______________ is responsible for the red brownish color of water?

A. Stratosphere
B. Troposphere
C. Ionosphere
D. None of these

A. Air binding
B. Shrinkage of filtering media
C. Mud balls
D. Expansion of filtering media

A. Dilution with inert material
B. Discharging to atmosphere through tall stacks after dilution
C. Disposing off in rivers & oceans
D. Filling in steel crates and shooting it off out of earth’s gravity

A. 20
B. 100
C. 400
D. 200

A. Turbidity
B. Color (Hazen)
C. Total solids
D. All A., B. & C.

A. 1-2
B. 5-10
C. 90-120
D. 1500-2500