Answer any four

1 (1)
The 3 days 20°C of domestic sewage is 400 mg/l. Estimate the 5 days BOD at 20°C. Assume value of k

_{20}=0.1/day(base e).
4 M

1 (2)
State the significance of BOD in waste water treatment.

4 M

1 (3)
Name the two factors used as criteria for selection of pipe diameter and slope in design of sewer.

4 M

1 (4)
Define Noise and explain why it should be regarded as an environmental pollutant.

4 M

1 (5)
Enumerate the various sources of air pollution.

4 M

2 (1)
What are traps, and why are they provided? How can the water seal in traps be broken? What methods are to be employed to maintain the seal?

10 M

2 (2)
Explain the various sewer appurtenances used in the sewerage system.

10 M

3 (1)
Explain in detail the dilution method of disposal of sewage. State the oxygen sag curve.

10 M

3 (2)
Differentiate between aerobic and anaerobic treatment of sewage giving major end products. Name one treatment method in each category.

10 M

4 (1)
Calculate the discharge of 1.25m circular sewer laid at a slope of 1 in 360, when it is running half full. Assume n in Manning's formula as 0.011.

10 M

4 (2)
Draw a flow diagram of an activated sludge plant for the treatment of sewage. Discuss the role of return sludge.

10 M

5 (1)
Design a septic tank for a hostel of 250 inmates with average daily sewage flow of 120 liters per head. Detention period is 30 hours. Cleaning interval is 6 months. Draw a neat sectional sketch showing all details.

12 M

5 (2)
Discuss the stage of biological action constituting sludge digestion.

8 M

6 (1)
Define sludge bulking and explain causes of sludge bulking.

8 M

6 (2)
Determine the size of a high rate trickling filter for the following data

sewage flow =4 MLD . Recirulation ration=1.3 BOD of raw sewage=300 mg/l

BOD removal in Primary tank=25% final effluent BOD desired=30 mg/l

sewage flow =4 MLD . Recirulation ration=1.3 BOD of raw sewage=300 mg/l

BOD removal in Primary tank=25% final effluent BOD desired=30 mg/l

12 M

7 (1)
Explain the causes, effects and control measures of Air pollution.

10 M

7 (2)
Explain factors affecting self purification of stream.

10 M

More question papers from Environmental Engineering - 2