STUPIDSID
Answer any one question from Q1 and Q2
1 (a)
State various formulas used for computation of velocity of flow in sewer. Hence explain the significance of maximum and minimum velocities to be generated in the sewer with suitable examples.
6 M
1 (b)
State the rational formula used for computation of storm water discharge. Hence determine the storm water discharge produced from a sewer district of 40 Hectors comprising different type of sub catchment as given below. The average intensity of rainfall in the area is 50mm/hour.
| Type of Catchment | % of Area | Coefficient of Runoff |
| 1. Built up area | 30 | 0.95 |
| 2. Road Surface | 15 | 0.8 |
| 3. Open Space | 25 | 0.2 |
| 4. Lawns and gardens | 40 | 0.15 |
6 M
1 (c)
What is DO fixation? Why it is necessary to fix DO during its measurement?
4 M
2 (a)
Explain the variation in sewage flow. How the variation in sewage flow is taken into account while designing the sewer.
4 M
2 (b)
List out various appurtenances used in sewerage system and hence explain the principle of working and need of oil & grease trap.
4 M
2 (c)
Design a circular sewer for conveyance of sewage generated from a town with population of 1.2 lakh and rate of water supply of 150 L/C/D. The sewer should be designed to carry maximum discharge while running 0.7 times full. Also check the velocity at minimum flow, it should be more than 0.6 m/s. Use following data.
i) Max.flow/Av.flow=3;
ii) Min.flow/Ave.flow=0.34;
iii) Manning's constant=0.013;
iv) Hydraulic elements at partial flow condition.
i) Max.flow/Av.flow=3;
ii) Min.flow/Ave.flow=0.34;
iii) Manning's constant=0.013;
iv) Hydraulic elements at partial flow condition.
| Proportional depth (d/D) | Proportional Velocity (v/V) | Proportional discharge (q/Q) |
| 0.7 | 1.12 | 0.838 |
| 0.4 | 0.902 | 0.337 |
| 0.3 | 0.776 | 0.196 |
| 0.2 | 0.615 | 0.088 |
| 0.1 | 0.401 | 0.021 |
8 M
Answer any one question from Q3 and Q4
3 (a)
Explain Oxygen sag, Deoxygenation and Reoxygenation curves with help of neat diagram
4 M
3 (b)
Explain with neat sketch, the principle and working of grit chamber. Describe the method of disposal of grit?
8 M
3 (c)
State the Streeter-Phelp's equation and explain each term in equation?
4 M
4 (a)
Explain different zones during self-purification of stream?
8 M
4 (b)
Design the screen chamber to treat a Maximum flow of 60 mld of sewage?
8 M
Answer any one question from Q5 and 6
5 (a)
State various modifications in Activated Sludge Process and hence explain any two with reference to process details, HRT, SRT and BOD removal efficiency.
9 M
5 (b)
Design a high rate single stage trickling filter for treating domestic sewage flow of 10MLD using N.R.C. formula. Use following data.
i) BOD5 of raw sewage = 300 mg/L,
ii) BOD removed during primary treatment =30%,
iii) Organic loading rate = 0.8Kg/m3/sup> /d,
iv) Hydraulic loading rate = 15m3/m3 /d,
v) Recirculation ratio =2.
Determine,
1) Volume of filter media
2) Dimensions of trickling filter
3) Efficiency of trickling filter
i) BOD5 of raw sewage = 300 mg/L,
ii) BOD removed during primary treatment =30%,
iii) Organic loading rate = 0.8Kg/m3/sup> /d,
iv) Hydraulic loading rate = 15m3/m3 /d,
v) Recirculation ratio =2.
Determine,
1) Volume of filter media
2) Dimensions of trickling filter
3) Efficiency of trickling filter
9 M
6 (a)
Draw a neat flow diagram of sewage treatment plant with trickling filter as method of secondary treatment.
4 M
6 (b)
Explain the principle and working of trickling filter.
4 M
6 (c)
Design a completely mixed activated sludge process for treating domestic sewage flow of 10MLD. Use following data.
i) BOD5 of raw sewage = 300 mg/L,
ii) BOD removed during primary treatment = 30%.
iii) Permissible effluent BOD = 30mg/L.
iv) Permissible suspended solids in treated effluent = 30mg/L of which 65% is biodegradable.
v) MLSS = 3000mg/L,
vi) Return sludge solids concentration = 10000mg/l,
vii) Ratio of VSS/SS =0.8,
viii) Kinetic constants: Y = 0.5, Kd = 0.05.
ix) Oxygen transfer capacity for aerators under field condition = 1.6 Kg/d.
Determine,
1) Influent and effluent BOD
2) Volume of aeration tank
3) Oxygen and power requirement
4) Rate of sludge wasting and sludge recirculation ratio.
i) BOD5 of raw sewage = 300 mg/L,
ii) BOD removed during primary treatment = 30%.
iii) Permissible effluent BOD = 30mg/L.
iv) Permissible suspended solids in treated effluent = 30mg/L of which 65% is biodegradable.
v) MLSS = 3000mg/L,
vi) Return sludge solids concentration = 10000mg/l,
vii) Ratio of VSS/SS =0.8,
viii) Kinetic constants: Y = 0.5, Kd = 0.05.
ix) Oxygen transfer capacity for aerators under field condition = 1.6 Kg/d.
Determine,
1) Influent and effluent BOD
2) Volume of aeration tank
3) Oxygen and power requirement
4) Rate of sludge wasting and sludge recirculation ratio.
10 M
Answer any one question from Q7 and Q8
7 (a)
Explain the symbiotic relationship between bacteria and algae in oxidation pond.
4 M
7 (b)
Differentiate between oxidation pond and aerated lagoon with reference to organic loading, HRT, BOD removal efficiency and method of aeration.
6 M
7 (c)
An aerated lagoon system is to be provided for treatment of sewage using following data:
i) Sewage flow = 10MLD,
ii) Raw sewage BOD 5 = 240mg/L,
iii) Desired BOD5 of treated effluent = 30mg/L,
iv) Hydraulic residence time (HRT) = 06 day,
v) Growth constants = 0.5, Kd = 0.05.
vi) Oxygen transfer capacity for aerators under field condition 1.6 Kg/d.
Determine:
1) Volume and dimensions of aerated lagoon,
2) Volatile solids produced in the aerated lagoon,
3) Oxygen and power requirement.
i) Sewage flow = 10MLD,
ii) Raw sewage BOD 5 = 240mg/L,
iii) Desired BOD5 of treated effluent = 30mg/L,
iv) Hydraulic residence time (HRT) = 06 day,
v) Growth constants = 0.5, Kd = 0.05.
vi) Oxygen transfer capacity for aerators under field condition 1.6 Kg/d.
Determine:
1) Volume and dimensions of aerated lagoon,
2) Volatile solids produced in the aerated lagoon,
3) Oxygen and power requirement.
6 M
8 (a)
Differentiate between activated sludge process and aerated lagoon and comments on suitability of these processes for treatment of sewage.
6 M
8 (b)
Explain the principle and working of facultative aerated lagoon.
4 M
8 (c)
Design an oxidation pond for treatment of domestic sewage, using following data.
i) Sewage flow = 2MLD,
ii) Raw sewage BOD5 = 240mg/L,
iii) Desired BOD5 of treated effluent = 30mg/L,
iv) Average solar radiation = 150Cal/cm2 /d,
v) Efficiency of sunlight utilization by algae = 0.06,
vi) Unit heat of combustion for algae = 6000Cal/g,
vii) Depth of pond = 1m.
viii) BOD 5 /BOD L = 0.68.
Determine,
1) Area and dimensions of oxidation pond,
2) Organic loading in KgBOD/Ha/d.
3) Hydraulic residence time (HRT).
i) Sewage flow = 2MLD,
ii) Raw sewage BOD5 = 240mg/L,
iii) Desired BOD5 of treated effluent = 30mg/L,
iv) Average solar radiation = 150Cal/cm2 /d,
v) Efficiency of sunlight utilization by algae = 0.06,
vi) Unit heat of combustion for algae = 6000Cal/g,
vii) Depth of pond = 1m.
viii) BOD 5 /BOD L = 0.68.
Determine,
1) Area and dimensions of oxidation pond,
2) Organic loading in KgBOD/Ha/d.
3) Hydraulic residence time (HRT).
6 M
Answer any one question from Q9 and Q10
9 (a)
Design a septic tank for 200 users. Water allowance is 120 liters per head per day. Also design a suitable soil absorption system if the percolation rate is 3min/sec. And depth of ground water table below GL is 1.5 m
8 M
9 (b)
Write short note on Up-flow Aerobic Sludge Blanket Reactor (UASBR).
5 M
9 (c)
Explain various method of sludge disposal along with merits and demerits.
5 M
10 (a)
Explain the aerobic sludge digestion process and also discuss the various design parameter of aerobic digester.
8 M
10 (b)
Explain the method of disposal of septic tank effluent.
5 M
10 (c)
What do you mean by sludge thickening? Explain the various method of sludge thickening.
5 M
Answer any one question from Q11 and Q12
11 (a)
Write short note on:
Equalization
Equalization
4 M
11 (b)
Neutralization
4 M
11 (c)
Sludge drying bed
4 M
11 (d)
Discharge standard for disposal of treated effluent in river.
4 M
Explain with a flow diagram for waste water treatment process of following Industry.
12 (a)
Sugar
4 M
12 (b)
Dairy
4 M
12 (c)
Textile
4 M
12 (d)
Distillery
4 M
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