1
Seat No.: Enrolment
GUJARAT TECHNOLOGICAL UNIVERSITY
PDDC SEMESTER-IV EXAMINATION WINTER 2018
Subject Code:X40601 Date: 17/11/2018
Subject Name: Environmental Engineering
Time: 02:30 PM TO 05:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
Q.1

Enlist the various methods of population forecast. Explain any two methods in details.
07

Explain river intake with a neat sketch showing all the components.
07
Q.2

Why coagulants are added to raw water? State the reasons for using alum salt as coagulant universally.
07

Differentiate between slow sand filter and rapid sand filter.
07
OR

The following data have been noted from the census department.
Year
1981
1991
2001
2011
Population
15000
23500
34000
5000
Calculate the probable population for the year 2031 and 2041 by arithmetic increase method and geometric increase method.
07
Q.3

What is the optimum dose of coagulant and how would you find it in laboratory?
07

Explain non-silting, non-scouring velocity with reference to design of sewers.
07
OR
Q.3

Write a short note on "Rapid sand Filters".
07

Explain in detail tree system of water distribution network.
07
Q.4

Give classification of sewers based on the construction methods.
07

What is grit chamber? Why is it necessary to provide this in the treatment of sewage? Discuss the design criteria of same.
07
OR
Q.4

What is nitrification? Discuss the effects of pH, DO and temperature on it.
07

A settling tank is designed for an overflow rate of 4000 what percentage of particles of diameter 0.05mm will be removed in this tank at 10°C.
07
Q.5

Differentiate between trickling filters and activated sludge process.
07

What is self cleansing velocity of wastewater flow in the sewers? What is dry weather flow?
07
OR
Q.5

Discuss what do you mean by sludge digester and explain it briefly.
07

What is meant by Design Period? State design periods for various components of wastewater treatment plant for a city.
07