M.Sc. (Environmental Science) (Semester II) (CBCS)
Examination, 2017
WATER AND WASTE WATER ENGINEERING
Day Date: Friday, 21-04-2017 Max. Marks: 70
Time: 10.30 AM to 01.00 PM
N.B. Answer any Five Question.
All Questions carry equal marks.
Question No. 1 is Compulsory.
Attempt any two from Q.No.2,3,and 4.
Attempt any two from Q.No.5,6 and 7.
Q.1 Select the answer among the following 14
Volatile oxidation corrosion product of metal is,
Fe2O3 Fe3O4
MoO3 FeO
Standard electrode potential of hydrogen is,
1.00 V 0.01 V
0.00 V 0.001 V
Which of the following gases accelerates rusting of iron?
CO2 NO2
SO2 All of above
Acid value is also called is,
Acid number Base number
Neutralization number Basic number
Conversion of Fe to Fe2+ is,
Oxidation Corrosion
Reduction None of above
Attached growth reactor is
Oxidation Pond RBC
Lagoons All the above
Maximum permissible velocity 1.5 m/sec, is adopted in drains
With beds of rocks and gravels Both and
Lined with stones Neither nor
The average temperature of sewage In India, is
100C 200C
150C 250C
In the activated sludge process
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Aeration is continued till stability
Aeration is done with an admixture of previously aerated
sludge
Sludge is activated by constant stirring
Water is removed by centrifugal action
10) In septic tanks.
Free board of 0.3 m may be provide
The baffles or tees are extended up to top level of scum
The clear space between the baffle top and covering
slab is about 7.5 cm
All the above
11) Primary treatment of sewage consists of removal of
Large suspended organic solids Sand and girt
Oil and grease Floating materials
12) The temperature affects the
Biological activity of bacteria in sewage
Viscosity of sewage
Solubility of gases in sewage
All the above
13) The maximum depth of sedimentation tanks, is kept
3 m 4 m
3.5 m 4.5 m
14) If the depletion of oxygen is found to be 5 ppm after
incubating a 2.5% solution of sewage sample for 5 days at
210C, B.O.D. of the sewage is
50 ppm 150 ppm
100 ppm 200 ppm
Q.2 Briefly explain the difference between an anaerobic reactor and
an anoxic reactor with its merits and demerits.
14
Q.3 What is chlorination? Why then is the breakpoint concentration
used rather than a lesser concentration?
14
Q.4 Explain the process and design aspect of Upflow anaerobic
sludge biological (UASB) digester.
14
Q.5 Write a short notes on following: 14
a. Wet air oxidation
b. Sludge thickening
Q.6 Write in with suitable illustration of the following: 14
a. Principles, applications and designing aspects of clarifier
b. Bioremediation of sludge with composting and conditioning
Q.7 Write an account on the following 14
a. Explain the various methods of population forecasting and
their applications
b. Principles, applications and designing aspects of Trickling
filter