The trap which is not used in house drainage system is

• Gully trap

• P trap

• S trap

• C trap

Growth of algae is useful in

• Sedimentation tank

• Slow sand filter

• Oxidation pond

• Sludge digestion tank

Most significant gaseous air pollutant is

• Carbon dioxide

• Oxygen

• Nitrogen

• Sulphur dioxide

Pipe which carries discharges from sanitary fittings such as water closets urinals etc called

• Waste pipe

• Vent pipe

• Discharge pipe

• Soil pipe

A septic tank is a

• Sedimentation tank

• Digestion tank

• Combined sedimentation & digestion tank

• Aeration tank

In the last man hole of house drainage system. The trap provided

• Gully trap

• S trap

• Floor trap

• Intercepting trap

The term which is measured as vertical distance between crown and dip of trap

• Crest width

• Water seal

• Dip depth

• Depth of water

The sewer appurtenance constructed to provide a connection between the high level branch sewer to low level main sewer

• Catch basin

• Man hole

• Drop manhole

• Deep man hole

The system of carrying sewage through sewer

• Dry system

• Conservancy system

• Partially seperate system

• Sewerage

Method of cleaning rapid sand filter

• Long laborious method

• CoMpressed air method

• Scraping

• Agitation and back washing