PTU B.Tech CIVIL 6th Semester May 2019 71087 ENVIRONMENT ENGINEERING II Question Papers

PTU Punjab Technical University B-Tech May 2019 Question Papers 6th Semester CIVIL Engineering (CE)

Roll No.
Total No. of Pages : 02
Total No. of Questions : 09
B.Tech.(CE) (2011 Onwards) (Sem.?6)
Subject Code : BTCE-606
M.Code : 71087
Time : 3 Hrs. Max. Marks : 60
SECTION-A is COMPULSORY consisting of TEN questions carrying T WO marks
SECTION-B contains FIVE questions carrying FIVE marks each and students
have to attempt any FOUR questions.
SECTION-C contains T HREE questions carrying T EN marks each and students
have to attempt any T WO questions.

Q1. Answer briefly :

a) Differentiate between separate sewer and combined sewer

b) What is meant by Dry weather flow (DWF)? How is it different from WWF?

c) How does the sewage flow fluctuate during 24 h period? How does this fluctuation

affect design of sewers?

d) What is meant by self cleansing velocity in sewers? How is it important?

e) Differentiate between lamp holes and man holes.

f) Give any two unit operations and unit processes from wastewater treatment.

g) Differentiate between Ejectors and Pumps

h) What is meant by biological solids retention time? How is it different from hydraulic

retention time?

i) What is meant by relative stability?

j) "Septic tank can only be considered as a primary treatment and the effluent needs

treatment before disposal". Why?
1 | M C o d e 7 1 0 8 7

( S 2 ) - 1 9 8 8

Q2. A main sewer is to be designed to receive a flow from 1 km2 area of a community where
population density is 200 persons/ha. The average flow is 150 lpcd. What is the design flow
for the main sewer?
Q3. Sketch and explain the construction and working of inverted siphons.
Q4. What are the different measures of organic content in wastewater? Discuss the importance
of BOD/COD ratio.
Q5. A channel - type grit chamber has a flow through velocity of 0.25 m/s, a depth of 0.8 m and
a length of 10 m. For inorganic grit particles with specific gravity 2.5, determine the
(assume v = 1.01 ? 10?2 cm2/s).
Q6. Differentiate between oxidation pond and oxidation ditch.

Q7. Compare the advantages and disadvantages of aerobic and anaerobic systems of wastewater
treatment. Use at least two examples from each to substantiate your point.
Q8. a) Calculate the surface area required for a stabilization pond to serve a population of
1 lakh sewage flow of 189 lpcd. BOD is 200 mg/L hydraulic loading of 250kg
BOD/d.ha. if the average liquid depth 1.5m. Calculate the retention time of the sewage
based on influent flow. Sketch the process diagram.

b) A trickling filter has a diameter of 20m and depth 2.5m. it is operated with a direct
circulation ratio of 1.5 and influent sewage rate of 2 million litres per day. Influent
BOD into the filter is 200 mg/L and effluent BOD is 30 mg/L. Calculate the hydraulic
loading rate and organic loading rate. What is the efficiency of the filter?
Q9. Write short notes differentiating the following :

a) One Pipe system and two pipe system of plumbing

b) Grease trap and Grit chamber

c) Pump capacity and pump efficiency

d) Stabilization pond and constructed wet land

NOTE : Disclosure of Identity by writing Mobile No. or Making of passing request on any
page of Answer Sheet will lead to UMC against the Student.
2 | M C o d e 7 1 0 8 7

( S 2 ) - 1 9 8 8

This post was last modified on 04 November 2019