Waste Water Engineering

A. Steel pipes
B. Steel shell coated from inside with cement mortar
C. Steel shell coated from outside with cement mortar
D. Both B. and C.

A. 4 to 8 hours
B. 8 to 16 hours
C. 16 to 24 hours
D. 24 to 36 hours

A. 100 cm
B. 90 cm
C. 80 cm
D. 50 cm

A. Used to remove the grease and oil
B. Those from which sludge is skimmed out
C. Tanks provided with self- cleansing screens
D. Improved version of grit chambers

A. Bazin
B. Crimp and Bruges
C. William-Hazen
D. Kutter

A. Brick sewer
B. Cast iron sewer
C. R.C.C. sewer
D. Lead sewer

A. Rate of digestion of sludge is more at higher temperature
B. Thermophilic organisms digest the sludge if the temperature ranges from 40° to 60°C
C. Mesophilic organisms digest the sludge if the temperature is between 25° and 40°C
D. All the above

A. Its intensity
B. Its direction
C. Its frequency
D. All the above

A. Hydrogen sulphide gas in excess, may cause corrosion of concrete sewers
B. 4 ppm of Dissolved Oxygen (D.O.) is ensured before discharging the treated sewage in river
C. Solubility of oxygen in sewage is 95% of that of distilled water
D. All the above

A. Bath rooms
B. Wash basins
C. Kitchen sinks
D. Toilets