Deck 5: Water Treatment Processes and Unit Operations

Question 1

In which unit operation, gases are released or absorbed in the water?

A)gas transfer
B)ion transfer
C)solute stabilization
D)solids transfer

Answer 1

gas transfer

Question 2

How many types of aerators are commonly used in the treatment of water?

A)2
B)3
C)4
D)5

Answer 2

4

Question 3

Which of the following process is used to remove the colloidal particles from water?

A)chemical precipitation
B)chemical coagulation
C)ion exchange
D)adsorption

Answer 3

chemical coagulation

Question 4

Flocculation of iron from water by the addition of lime is an example of which of the following process?

A)chemical precipitation
B)chemical coagulation
C)ion exchange
D)adsorption

Question 5

In which unit operation objectionable solutes are converted into unobjectionable forms without removal?

A)gas transfer
B)ion transfer
C)solute stabilization
D)solids transfer

Question 6

In which form of solute stabilization, hydrogen sulfide in water is oxidized into sulfate?

A)chlorination
B)liming
C)re-carbonation
D)super-chlorination

Question 7

Which form of solute stabilization occurs when water passes through limestone?

A)chlorination
B)liming
C)re-carbonation
D)super-chlorination

Question 8

In which process, excess lime is converted into bicarbonate?

A)chlorination
B)liming
C)re-carbonation
D)super-chlorination

Question 9

By which process, odour producing substances is oxidized?

A)chlorination
B)liming
C)re-carbonation
D)super-chlorination

Question 10

Solids are removed from the water by which of the following unit operation?

A)inter facial contact
B)solid stabilization
C)ion transfer
D)solids transfer

Question 11

Dealkalization results in removal of all the ions from the water.

Question 12

Organic contaminants are removed from the water by the process of________    

A)water softening
B)demineralization
C)absorption
D)adsorption

Question 13

 ____________ is an operation designed to force agitation in the fluid and induce coagulation.

A)sedimentation
B)flocculation
C)disinfection
D)aeration

Question 14

What is the normal value of the detention period adopted in a flocculator for design purpose?

A)30min
B)60min
C)90min
D)100min

Question 15

The design value of the velocity of flow in a flocculator is________      

A)0.2-0.8m/s
B)0.3-0.5m/s
C)0.6-0.8m/s
D)0.1-0.5m/s

Question 16

What is the detention period of a clarifier used in the treatment of water?

A)1hour
B)2hours
C)3hours
D)4hours

Question 17

The pulsator clarifier is a type of

A)horizontal flow sludge tank
B)vertical flow sludge tank
C)circular sludge tank
D)plain sedimentation tank

Question 18

Which device solved the problem of unstable hydraulic conditions and operation of sludge removal equipment?

A)centrifugal pump
B)pulsator clarifier
C)tube settler
D)flocculator

Question 19

In which device, the primary mixing is followed by a secondary reaction zone resulting in formation of sludge blanket?

A)centrifugal pump
B)flocculator
C)tube settler
D)solid contact clarifier

Question 20

In which type of tube settler, tubes are slightly inclined in the direction of normal flow?

A)solid contact clarifier
B)steeply inclined tube settler
C)vertical tube settler
D)horizontal tube settler

Question 21

Ion exchange units are known as________    

A)water hardeners
B)water softeners
C)water purifiers
D)exchangers

Question 22

Water softener units work most efficiently with particulate water.

Question 23

Which of these have a negative electrical charge?

A)calcium
B)magnesium
C)sodium
D)chloride

Question 24

The ions with opposite charge can be exchanged.