Environmental Engineering (3160611) MCQs

MCQs of Sewage : Characteristics, Treatment and Disposal

Showing 11 to 20 out of 27 Questions
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11.

If the over land flow from the critical point to the drain is 8 km and the difference in level is 12.4 m, the inlet time is

(a)

2 hours
(b)

3 hours
(c)

4 hours
(d)

5 hours
Answer:

Option (c)

12.

The coagulant widely used for sewage treatment, is

(a)

alum
(b)

ferric chloride
(c)

ferric sulphate
(d)

chlorinated copperas.
Answer:

Option (b)

13.

For detecting the nitrates in sewage, the colour may be developed by adding

(a)

Pottassium permanganate
(b)

Sulphuric acid and napthamine
(c)

Phenol-di-sulphuric acid and pottassium hydroxide
(d)

None of these
Answer:

Option (c)

14.

The sewage treatment units in which anaerobic decomposition of organic matter is used, are called

(a)

imhoff tanks
(b)

trickling filters
(c)

sludge sedimentation tanks
(d)

none of these.
Answer:

Option (b)

15.

The spacing of man holes along a straight portion of a sewer is 300 m, the diameter of the sewer may be

(a)

0.9 cm
(b)

1.2 m
(c)

1.5 m
(d)

> 1.5 m.
Answer:

Option (d)

16.

For complete stabilisation of organic matter in polluted water, it takes

(a)

5 days
(b)

10 days
(c)

20 days
(d)

30 days
Answer:

Option (c)

17.

No treatment of the sewage is given if dilution factor is

(a)

less than 150
(b)

between 150 to 200
(c)

between 200 to 300
(d)

more than 500
Answer:

Option (d)

18.

The bottom of the sewage inlet chamber of septic tanks, is provided an outward slope

(a)

1 in 5
(b)

1 in 10
(c)

1 in 15
(d)

1 in 20
Answer:

Option (b)

19.

For a continuous flow type of sedimentation tanks

(a)

width of the tank is normally kept about 6 m
(b)

length of the tank is normally kept 4 to 5 times the width
(c)

length of the tank is normally kept 4 to 5 times the width
(d)

all the above.
Answer:

Option (d)

20.

The temperature affects the

(a)

biological activity of bacterias in sewage
(b)

viscosity of sewage
(c)

solubility of gases in sewage
(d)

all the above.
Answer:

Option (d)

Showing 11 to 20 out of 27 Questions
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