STUPIDSID
1 (a)
Explain briefly the important features of the different 'system of sewerage'. Also, state their merits and demerits.
12 M
1 (b)
Differentiate between the following:
i) Sullage and sewage
ii) Raw sewage and septic sewage
iii) Dry weather flow and wet weather flow
iv) Lateral sewer and outfall sewer.
i) Sullage and sewage
ii) Raw sewage and septic sewage
iii) Dry weather flow and wet weather flow
iv) Lateral sewer and outfall sewer.
8 M
2 (a)
With a neat sketch explain i) The objectives, ii) Location, iii) Details of a manhole. Bring out the functions of a manhole.
10 M
2 (b)
Design a circular sewer to serve a Residential suburb of a city with the following data.
i) Area of suburb = 50 hectares
ii) Population = 6000 persons
iii) Average rate of water supply = 20 lpcd
iv) Subtraction allowance = 20%.
v) Critical design rainfall intensity = 40 mm/hr
vi) Average available ground slope 1 in 1000.
vii) Co-efficient of runoff = 0.45.
viii) Manning's N=0.012.
Maximum flow in the sewerage system may be taken as three times the average flow.
i) Area of suburb = 50 hectares
ii) Population = 6000 persons
iii) Average rate of water supply = 20 lpcd
iv) Subtraction allowance = 20%.
v) Critical design rainfall intensity = 40 mm/hr
vi) Average available ground slope 1 in 1000.
vii) Co-efficient of runoff = 0.45.
viii) Manning's N=0.012.
Maximum flow in the sewerage system may be taken as three times the average flow.
10 M
3 (a)
Explain the terms BOD and COD and their importance in waste water treatment.
4 M
3 (b)
Deduce an expression for determining BOD at any time.
8 M
3 (c)
The following observations were made on a 5% dilution of sample of sewage
D.O. of blank = 3.3 mg/l
D.O of diluted sample after 5 days incubation = 0.89 mg/lit.
D.O. of origin sample = 0.55 mg/l
Calculate the ultimate B.O.D of sample. Assume KD = 0.1/day.
D.O. of blank = 3.3 mg/l
D.O of diluted sample after 5 days incubation = 0.89 mg/lit.
D.O. of origin sample = 0.55 mg/l
Calculate the ultimate B.O.D of sample. Assume KD = 0.1/day.
8 M
4 (a)
Draw a flow diagram from an outfall to the disposal into a river valley after complete treatment for a proposed sanitary project for a town. Indicate the purpose of each unit adopted during the process treatment.
12 M
4 (b)
What are the important salient properties of 'Activated sludge process'? Explain the process involved in treating domestic sewage.
8 M
5 (a)
Explain briefly the dilution method of disposal of sewage. What are the factors which influence the choice of the method to be adopted?
8 M
5 (b)
Discuss in detail the process deoxygenation and reoxygenation with respect to self purification of natural waters with a neat sketch.
12 M
6 (a)
What do you understand by the term 'Low cost waste treatment'?
4 M
6 (b)
Explain with a neat sketch the principle and process working of an 'Oxidation pond'.
6 M
6 (c)
Design an oxidation pond to treat sewage in a tropical country, from a colony of 10,000 persons. The B.O.D. of the sewage is 300 mg/l and flow is 120 lpcd 90% of water supplied is collected as sewage. Check the detention time. Sketch the detail of the oxidation pond.
10 M
7 (a)
What is sludge gas? What is its typical composition? What are the uses of sludge gas?
4 M
7 (b)
Explain briefly the different stages of sludge digestion process in a 'Digester'. With a neat sketch explain the constructional details of sludge digestion tank.
8 M
7 (c)
Design sludge digestion tank for one lakh population. The sludge content per capita per day is 0.07kg. The moisture of sludge is 94%. The specific gravity of wet sludge is 1.02 and 3.5% of fresh sludge is being mixed with digested sludge.
8 M
Write short notes on the following:
8 (a)
Sewage farming.
5 M
8 (b)
Testing of a sewer time
5 M
8 (c)
Sludge bulking and sludge volume index
5 M
8 (d)
Oxidation ditch.
5 M
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