Temporary hardness of water is due to the presence of

 

(A) nitrates

 

(B) sulphates

 

(C) carbonates

 

(D) chloride

The suitable method of forecasting population for a young and rapidly increasing city is

(A) graphical method

(B) incremental increase method

(C) geometrical increase method

(D) arithmetical increase method

Zero hardness of water is achieved by

(A) using excess alum dosage

(B) ion exchange method

(C) excess lime treatment

(D) using lime soda process

For trunk and out fall, the type of sewers generally used is

(A) circular shaped

(B) horse shoe shaped

(C) parabolic shaped

(D) standard egg shaped

For an area developed in haphazard way, the type of layout of water distribution system preferred as

(A) radial system

(B) ring system

(C) grid iron system

(D) dead end system

Which one of the following is not ground water?

(A) from river side radial collector wells

(B) from infiltration gallaries

(C) water from natural springs

(D) rooftop water stored in underground tank

Which one of the following is not ground water?

(A) from river side radial collector wells

(B) from infiltration gallaries

(C) water from natural springs

(D) rooftop water stored in underground tank

The layer on the top of a filtering medium formed by organic impurities is known as

(A) dirty skin

(B) tube settler

(C) permeable layer

(D) filtering layer

In treatment swimming pool water the filtration system to be used is

(A) slow sand filters

(B) pressure filters

(C) rapid sand filters

(D) any of the above

The sewer which obtains its discharge from two or more sewers is known as

(A) common sewer

(B) outfall sewer

(C) trunk sewer

(D) depressed sewer

The chemical most commonly used to increase speed of sedimentation of sewage is

(A) lime

(B) sodium permanganate

(C) copper sulphate

(D) sulphuric acid