Question 1

What is the horizontal velocity considered for grit chamber?

Accepted Answer

A)  0.25-0.4m/sec
B)  0.6-0.9 m/sec
C)  1-2 m/sec
D)  3-4m/sec A

Question 2

Aerated grit chambers are usually designed to remove particles in which range of size?

Accepted Answer

A)  0.1mm diameter
B)  0.35 mm diameter
C)  0.21 mm diameter
D)  0.41 mm diameter C

Question 3

Usually while designing what is the range of length of the aerated grit chamber assumed?

Accepted Answer

A)  7.5-20
B)  4-6 m
C)  25 m
D)  50 m A

Question 4

What does the bacterium use to grow?

Accepted Answer

A)  Oxygen
B)  Organic pollutants
C)  Water
D)  Carbon-dioxide

Question 5

When the aeration system shuts off, the basin begins to perform as a ______

Accepted Answer

A)  Primary clarifier
B)  Secondary clarifier
C)  Anaerobic unit
D)  Aeration unit

Question 6

Which of the following ion get released from the anion exchange column?

Accepted Answer

A)  CO3-2
B)  OH-
C)  Cl-
D)  SO4-2

Question 7

Usually while designing what is the range of the width of the aerated grit chamber assumed?

Accepted Answer

A)  0.5-2 m
B)  8-10 m
C)  2.5-7.0m
D)  12m

Question 8

Activated sludge process degrade organics and _________

Accepted Answer

A)  Improve nutrients
B)  Remove nutrients
C)  Remove odour
D)  Remove taste

Question 9

Stoke's law holds good for Reynolds's number ______

Accepted Answer

A)  Less than 1
B)  Equal to 1
C)  Greater than 1
D)  Nearer to 1

Question 10

Which of these is not a grit removal equipment installed in the aerated grit chamber?

Accepted Answer

A)  Screw conveyers
B)  Tubular conveyers
C)  Jet pumps
D)  Communitors

Question 11

Usually while designing what is the range of depth of the aerated grit chamber assumed?

Accepted Answer

A)  0.5-2 m
B)  8-10 m
C)  2-5 m
D)  12 m

Question 12

What is the specific gravity of settleable particles in the grit chamber?

Accepted Answer

A)  2.98
B)  2.56
C)  2.65
D)  2.89

Question 13

What does SBR stand for?

Accepted Answer

A)  Secondary batch reactor
B)  Sequential biological reactor
C)  Secondary biological reactor
D)  Sequential batch reactor

Question 14

What is required to keep the activated sludge suspended?

Accepted Answer

A)  Carbon-dioxide
B)  Nitrogen
C)  Oxygen
D)  Ammonia

Question 15

What is the amount of grit quantities captured by the aerated grit chamber?

Accepted Answer

A)  0.004-0.20 m3/103.m3
B)  0.25 m3/103.m3
C)  3
D)  0.5 m3/103.m3

Question 16

Grit chamber is similar to which of the following?

Accepted Answer

A)  Screening unit
B)  Sedimentation tank
C)  Coagulation tank
D)  Sand bed

Question 17

At what depth are the air diffusers placed in the grit chamber?

Accepted Answer

A)  0.6-0.9 m
B)  1-2 m
C)  0.1-0.4m
D)  0.45-0.6 m

Question 18

________ combines aeration basin and secondary clarifier into single unit.

Accepted Answer

A)  Primary clarifier
B)  Aerobic unit
C)  Sequential batch reactor
D)  Secondary clarifier

Question 19

Ion-exchange resin is ____________

Accepted Answer

A)  Linear
B)  Low molecular weight
C)  Organic polymer with porous structure
D)  Soluble

Question 20

SBR operates as ________ process.

Accepted Answer

A)  Batch
B)  Continuous
C)  Semi-continuous
D)  Discontinuous

Exam 7: Grit Chambers and Activated Sludge Processes