Sludge volume index is defined as the ratio of_______________?

A. Percentage of sludge by volume to percentage of suspended solids by weight
B. Percentage of sludge by volume to percentage of total solids by weight
C. Percentage of suspended solids by weight to percentage of sludge by volume
D. Percentage of total solids by weight to percentage of sludge by volume

When there is no recirculation of sewage, then recirculation factor is_______________?

A. 0
B. 1
C. Infinity
D. None of the above

The pipe which is used to carry the discharge from sanitary fittings like bath rooms, kitchens etc. is called_______________?

A. Waste pipe
B. Soil pipe
C. Vent pipe
D. Antisiphonage pipe

Most of the bacteria in sewage are______________?

A. Parasitic
B. Saprophytic
C. Pathogenic
D. Anaerobic

A pipe which is installed in the house drainage to preserve the water seal of traps is called______________?

A. Vent pipe
B. Antisiphonage pipe
C. Waste pipe
D. Soil pipe

The process of lagooning is primarily a means of________________?

A. Reducing the excessive flow in sewers
B. Disposing of sludge
C. Increasing the capacity of storage re-servoirs
D. Increasing flow of sewage through imhoff tanks

The gas from sludge digestion tank is mainly composed of __________________?

A. Nitrogen
B. Carbon dioxide
C. Hydrogen sulphide
D. Methane

For the same solid content, if the quantity of sludge with moisture content of 98% is X, then the quantity of sludge with moisture content of 96% will be__________________?

A. X/4
B. X/2
C. X
D. 2x

For normal sludge, the value of sludge index for Indian conditions is________________?

A. 0 to 50
B. 50 to 150
C. 150 to 350
D. 350 to 500

For satisfactory working of a sludge digestion unit, the pH range of digested sludge should be maintained as___________________?

A. 4.5 to 6.0
B. 6.5 to 8.0
C. 8.5 to 10.0
D. 10.5 to 12.0