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

1(b) Draw a neat sketch of Drop manhole.

1(c)Why velocity needs to be controlled in grit chamber?

1(d) What is sludge volume index? What is its significance?

1(e) Explain effect of noise pollution with control measures

2(a) Give classification of air pollutants and control measures for gaseous and particulate matter.

2(b) Design the dimensions of a septic tank for the following data:

No. of people = 130
Sewage/capita/day = 120 lit
Desludging period = 1 year
Length: Width = 4:1

3(a) Explain with neat sketch the working of a Trickling Filter. What is the principle on which it works?

3(b) Design a conventional activated sludge plant to treat domestic sewage, given the following data:

Population = 36,000
Average sewage flow = 180 lped
BOD of sewage = 240 mg/lit
BOD removed in primary clarifier = 25%
Overall BOD reduction = 85%
Based on the information above, determine

• Volume of aeration tank
• Aeration period or H.R.T
• Sludge Retention Time
• Tank dimensions

4(a) Calculate 2 day $37^0 C$ BOD of sewage sample whose 5 day $20^0C$ BOD is 180 $mg/lit$. Assume $K_D$ at $20^0 C$ as 0.1

4(b) Explain the necessity and process mechanism of anaerobic digestion of sludge. How the solid, liquid and gaseous products of digestion are disposed off?

5(a) Design a sewer to serve a population of 35,000; the daily per capita water supply allowance being 160 litres, of which 80 percent finds its way into the sewer. The slope available for the sewer to be laid is 1 in 600 and the sewer should be designed to carry four times the dry weather flow when running full. What would be the velocity of flow in the sewer when running full?

5(b) Differentiate between one pipe and single stack plumbing systems with neat sketch.

6(a) Natural forces of self-purification.

6(b) Anti-siphonage pipe

6(c) Oxidation pond

6(d) Sludge Thickner

6(e) Sampling of sewage