Question Paper: Environmental Engineering 2 Question Paper - Dec 17 - Civil Engineering (Semester 7) - Mumbai University (MU)
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## Environmental Engineering 2 - Dec 17

### Civil Engineering (Semester 7)

Total marks: 80
Total time: 3 Hours
INSTRUCTIONS
(1) Question No.1 is compulsory.
(2) Attempt any three questions from remaining five questions.
(3) Assume any suitable data where ever required.
(4) Figures to the right indicate full marks.

1(a) What is conservancy system and water carriage system?
(5 marks) 1619

1(b) Compare, in a tabular form, low rate and high rate tricking filters.
(5 marks) 521

1(c) What are drop manholes and lamp holes?
(5 marks) 1620

1(d) What is self-purification of stream?
(5 marks) 00

2(a) Design a septic tank for a hostel housing 125 persons. Also deign the soil absorption system for the disposal of the septic tank, effluent, assuming the percolation rate as 20 minutes per cm.
(10 marks) 1115

2(b) Explain with the help of diagram, various systems of plumbing used for house drainage.
(10 marks) 1116

3(a) Explain the necessity and process mechanism of anaerobic digestion of sludge. How the solid, liquid and gaseous product of digestion are disposed off?
(10 marks) 514

3(b) Design a conventional activated sludge plant to treat domestic sewage, given the following data:
Population=40,000
Average sewage flow=180 lpcd
BOD of sewage = 240mg/lit
BOD removed in primary clarifier = 25%
Overall BOD reduction = 80%
Based on the information above, determine

• a) Volume of acration tank.
• b) Aeration period or H.R.T.
• c) Sludge Retention Time
• d) Tank dimensions

(10 marks) 00

4(a) During BOD test conducted on a 5% dilution of waste , the following observations were taken.

• i) DO of aerated water used for dilution = 3.6mg/lit
• ii) DO of original sample = 0.8mg/lit
• iii) DO of diluted sample after 5 day incubation = 0.7mg/lit
Compute a) 5day BOD b)Ultimate BOD

(10 marks) 00

4(b) Explain with diagram various equipment's used for the control of particulate pollutants.
(10 marks) 00

5(a) Draw a neat sketch of a typical sewage pumping station and describe in brief the functions of each.
(8 marks) 00

5(b) Explain in brief different testing methods for sewer pipes and why sewers run partially full.
(6 marks) 529

5(c) Design a circular primary settling tank for a town having a population of 50,000 with a water supply of 180 litres per capita per day.
(6 marks) 00

Q6) Write short note on (any four)

• a) Sampling of sewage. 588

• b) Control measures of noise pollution. 745

• c) Recycling and reuse of waste water.

• d) Grit Chamber. 582

• e) Anti-siphonage pipe. 3068

• f) Inverted siphon.

(20 marks)