STUPIDSID
Answer any one question from Q1 and Q2
1 (a)
Describe the relationship between TOC, COD and BOD, as well as explain effect of change of life on sewage quality.
8 M
1 (b)
Find the minimum velocity and gradient required to transport coarse sand through a sewer of 60 cm dia. with sand particles of 1 mm dia. and specific gravity 2.66. Assume β = 0.06 and f = 0.02. Assume the sewer to run half full. Take N = 0.012.
8 M
2 (a)
A community discharges 20 MLD of wastewater. Draw a conventional flow diagram for Treating this wastewater. Discuss the concepts on which the design of the proposed treatment Units are based.
8 M
2 (b)
During BOD test conducted on a 5% dilution of waste, the following observations were taken.
i) Do of aerated water used for dilution = 3.6 mg/L
ii) Do of original sample = 0.8 mg/L
iii) Do of diluted sample after 5 day incubation = 0.7 mg/L
Compute:
a) 5 day BOD and
b) Ultimate BOD
Assume deoxygenation constant at test temperature as 0.12.
i) Do of aerated water used for dilution = 3.6 mg/L
ii) Do of original sample = 0.8 mg/L
iii) Do of diluted sample after 5 day incubation = 0.7 mg/L
Compute:
a) 5 day BOD and
b) Ultimate BOD
Assume deoxygenation constant at test temperature as 0.12.
8 M
Answer any one question from Q3 and Q4
3 (a)
With a neat diagram explain the various zones and types of settling tank.
8 M
3 (b)
Give the streeter - phelps equation and explain each term in the equation.
8 M
4 (a)
What do you understand by self-purification property of a stream? Explain the factors affecting this property.
8 M
4 (b)
Assuming suitable design criteria, design a horizontal flow type grit chamber for a proposed sewage treatment plant expected to treat 60,000 m3/day maximum flows. The estimated average and minimum sewage flows are 45,000 m3/day and 15,000 m3/day respectively. The flow through velocity of 0.3 m/s is to be controlled by a proportional weir.
8 M
Answer any one question from Q5 and 6
5 (a)
Write short note on:
i) F/M Ratio
ii) MLVSS
iii) MCRT
iv) SLR
i) F/M Ratio
ii) MLVSS
iii) MCRT
iv) SLR
8 M
5 (b)
Assuming reactor volume equal to 5000 m3, and MLSS concentration in the reactor as 3000 mg/L. Compute the sludge production rate, and sludge wasting rates
i) from recycled line and
ii) from the reactor for an activated sludge plant design to operate mean cell residence time of 10 days to maintain 1000 mg/L concentration of recycled sludge
i) from recycled line and
ii) from the reactor for an activated sludge plant design to operate mean cell residence time of 10 days to maintain 1000 mg/L concentration of recycled sludge
10 M
6 (a)
Describe the removal mechanism in a rotating biological contactor.
8 M
6 (b)
Design a high rate single stage trickling filter for treating the following wastewater of a town having population of 4000 persons:
i) Domestic sewage @ 150 lpcd having 200 mg/l of BOD.
ii) Industrial wastewater @ 0.25 million litres per day having 600 mg/l of BOD.
Assume the following.
a) BOD removal in primary clarifier = 35%.
b) Permissible organic loading of filter = 8000 mg/hec-m/day (Excluding recirculated sewage).
Also determine the efficiency of the filter and BOD of the effluent.
i) Domestic sewage @ 150 lpcd having 200 mg/l of BOD.
ii) Industrial wastewater @ 0.25 million litres per day having 600 mg/l of BOD.
Assume the following.
a) BOD removal in primary clarifier = 35%.
b) Permissible organic loading of filter = 8000 mg/hec-m/day (Excluding recirculated sewage).
Also determine the efficiency of the filter and BOD of the effluent.
10 M
Answer any one question from Q7 and Q8
7 (a)
Classify the difference between the aerated lagoon and oxidation ditch with respect to process design.
8 M
7 (b)
Design an oxidation pond for treating sewage from a hot climatic residential colony with 5000 persons, contributing sewage @ 120 litres per capita per day. The 5-day BOD of sewage is 300 mg/L.
8 M
8 (a)
Elaborate phytoremediation technology for wastewater treatment.
8 M
8 (b)
Elaborate theory of root zone cleaning system.
8 M
Answer any one question from Q9 and Q10
9 (a)
For a residential building, septic tank and the soil absorption system for the disposal of the septic tank effluent is to be designed having following data:
No. of persons = 150
Percolation rate = 15 minutes per cm
No. of persons = 150
Percolation rate = 15 minutes per cm
8 M
9 (b)
Give a simple flow chart for sludge treatment and digestion; also explain the factors affecting sludge digestion.
8 M
10 (a)
Explain methods of sludge treatment and disposal along with advantages & disadvantages.
8 M
10 (b)
Explain principle, mechanism, advantages & disadvantages of Up-flow Anaerobic Sludge Blanket (UASB) Reactor.
8 M
Write short note on the following chemical treatments of Industrial wastewaters.
11 (a)
Methods of sampling
3 M
Answer any one question from Q1 and Q2
11 (b)
Equalization
3 M
11 (c)
Neutralization
3 M
11 (d)
Chemical Coagulation
3 M
11 (e)
Adsorption
3 M
11 (f)
Air-stripping
3 M
12
Give the range of important characteristics of wastewater from the following industries and draw a suitable flow diagram for treatment of each industry.
a) Distillery Industry
b) Sugar Industry
c) Pulp and paper Industry.
a) Distillery Industry
b) Sugar Industry
c) Pulp and paper Industry.
18 M
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