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Civil Engineering :: Waste Water Engineering

  1. In a sludge tank, the gas mainly produced, is

  2. A.

     Oxygen

    B.

     Nitrogen

    C.

     Hydrogen

    D.

     Carbon dioxide


  3. A five day B.O.D. at 15°C of the sewage of a town is 100 kg/day. If the 5 day B.O.D. per head at 15°C for standard sewage is 0.1 kg/day, the population equivalent is

  4. A.

     100

    B.

     1000

    C.

     5000

    D.

     10000


  5. The gas which may cause explosion in sewers, is

  6. A.

     Carbondioxide

    B.

     Methane

    C.

     Ammonia

    D.

     Carbon monoxide


  7. Sludge banks are formed if sewage is disposed of in

  8. A.

     Rivers

    B.

     Seas

    C.

     Lakes

    D.

     None of these


  9. The rate of accumulation of sludge in septic tanks is recommended as

  10. A.

     30 litres/person/year

    B.

     25 litres/person/year

    C.

     30 litres/person/month

    D.

     25 litres/person/month


  11. In SI units the power of sound is represented in

  12. A.

     Kgs

    B.

     Joules

    C.

     Newtons

    D.

     Watts


  13. Disposal to sewage in large cities, is done in

  14. A.

     Irrigation

    B.

     Dilution

    C.

     Oxidation

    D.

     Purification


  15. A well oxidized sewage contains nitrogen mainly as

  16. A.

     Nitrates

    B.

     Nitrites

    C.

     Free ammonia

    D.

     None of these


  17. The settlement of a particle in sedimentation tank, is affected by

  18. A.

     Velocity of flow

    B.

     Viscosity of water

    C.

     Size and shape of solid

    D.

     All the above


  19. Skimming tanks are

  20. 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