Civil Engineering - Waste Water Engineering

6. 

3.0 ml of raw sewage is diluted to 300 ml. The D.O. concentration of the diluted sample at the beginning of the test was 8 mg/l. After 5 day-incubation at 20°C, the DO. concentration was 5 mg/l. The BOD of raw sewerage is

A. 100 mg/l
B. 200 mg/l
C. 300 mg/l
D. 400 mg/l.

Answer: Option C

Explanation:

No answer description available for this question. Let us discuss.

7. 

The arrangement made for passing the sewer line below an obstruction below the hydraulic gradient lines called

A. inverted syphon
B. depressed sewer
C. sag pipe
D. all of these.

Answer: Option D

Explanation:

No answer description available for this question. Let us discuss.

8. 

The angle subtended by the surface of sewer water with partial flow, at sewer centre is 120°, the depth of sewerage is

A. 20 cm
B. 25 cm
C. 40 cm
D. 50 cm
E. 60 cm.

Answer: Option D

Explanation:

No answer description available for this question. Let us discuss.

9. 

Imhoff cone is used to determine

A. settlable solids
B. suspended solids
C. dissolved solids
D. none of these.

Answer: Option A

Explanation:

No answer description available for this question. Let us discuss.

10. 

The sewage discharge in a detritus tank of a treatment plant is 576 litres/sec with flow velocity of 0.2 m/sec. If the ratio of width to depth is 2, the depth is

A. 100 cm
B. 110 cm
C. 120 cm
D. 150 cm.

Answer: Option C

Explanation:

No answer description available for this question. Let us discuss.