Deck 4: Water Treatment and Softening Processes

Question 1

The secondary clarifiers are ________

A)Circular
B)Rectangular
C)Square
D)Triangular

Answer 1

Circular

Question 2

Which of the following is not commonly used as a filter material in the treatment of water?

A)Sand
B)Anthracite
C)Crushed rock
D)Garnet sand

Answer 2

Crushed rock

Question 3

Which of the following is correct regarding the cheapest filter material used in water treatment?

A)Sand>Anthracite>Garnet sand
B)SandGarnet sand
C)Sand
D)Sand=Anthracite>Garnet sand

Answer 3

Sand>Anthracite>Garnet sand

Question 4

The uniformity characteristics of sand expressed in terms of __________

A)Effective size
B)Effective size and uniformity coefficient
C)Uniformity coefficient
D)Mean velocity

Question 5

____ represents the size of sand particle such that 10% of particles are finer than this size.

A)D0.1
B)D1
C)D10
D)D100

Question 6

What is CU in the expression CU= D60/D10 where D60 and D10 are the sizes of particle such that 60% and 10% of the particles are finer than these sizes respectively?

A)Coefficient of compaction
B)Coefficient of consolidation
C)Uniformity coefficient
D)Effective size

Question 7

The effective size of sand of the slow sand filter is __________

A)0.1-0.2mm
B)0.2-0.3mm
C)0.4-0.7mm
D)1-2mm

Question 8

What is the value of specific gravity of sand filter?

A)2
B)2.6
C)3.1
D)3.5

Question 9

The value of uniformity coefficient for uniformly graded sand is ______

A)0
B)1
C)10
D)100

Question 10

The value of specific gravity for Garnet sand is ____

A)2.1
B)3.6
C)4.2
D)5.1

Question 11

Which of the following statement is correct?

A)Ignition loss of filter should not exceed 3%
B)Wearing loss of filter sand should not exceed 5%
C)The range of CU for the slow sand filter is 3-5
D)The range of CU for the rapid sand filter is 3-5

Question 12

In which process of water softening, ion exchange phenomenon takes place?

A)Lime soda process
B)Zeolite process
C)Boiling
D)Demineralization process

Question 13

In which process of water softening, the chemicals are added to remove hardness from water?

A)Lime soda process
B)Zeolite process
C)Boiling
D)Demineralization process

Question 14

Zeolites are complex compound of ____________

A)Aluminium and lime
B)Silica and soda
C)Aluminium, silica and soda
D)Lime and soda

Question 15

The color of the artificial zeolite permutit is ____________

A)Grey
B)Yellow
C)Green
D)White

Question 16

Natural zeolite is mainly processed from ____________

A)White sand
B)Green sand
C)Grey sand
D)Red sand

Question 17

The color of the natural zeolite is ____________

A)Green
B)Grey
C)Black
D)Blue

Question 18

The chemical formula of Permutit is ____________

A)SiOAl₂O₃Na₂O
B)SiO₂Al₂O₃Na₂O
C)SiO₂Al₂O₃NaO
D)SiO₃Al₂O₃Na₂O

Question 19

Permutit has an exchange value of ________ grams of hardness per m3 of zeolite.

A)10,000
B)20,000-30,000
C)35,000-40,000
D)40,000-50,000

Question 20

The thickness of the layers of filter sand of zeolite softener is ____________

A)20cm
B)30cm
C)40cm
D)100cm

Question 21

Which of the following is a disadvantage of the zeolite process?

A)No sludge is formed
B)The process is almost automatic
C)Suspended impurities get deposited around the zeolite particles
D)Zero hardness can be occurred

Question 22

Water is mainly used in boilers for the generation of ________________

A)Power
B)Electricity
C)Steam
D)Current

Question 23

Which of the following should not be a composition of boiler-feed water?

A)Hardness should be below 0.2ppm
B)Its caustic alkalinity should lie between 0.15 to 0.45 ppm
C)Its soda alkalinity should be 0.45-1 ppm
D)Its caustic alkalinity should be 1.5-2 ppm

Question 24

Which of the following is not a result of the excess of impurity in boiler-feed?

A)Scale and sludge formation
B)Decomposition
C)Corrosion, priming and foaming
D)Caustic embrittlement

Question 25

If the precipitate formed is soft, loose and slimy, these are __________ and if the precipitate is hard and adhering on the inner wall, it is called _____________

A)Sludges, scale
B)Scale, sludges
C)Sludges, rodent
D)Scale, rodent