Q.1
In a sedimentation tank (length L, width B, depth D) the settling velocity of a particle for a discharge Q, is
Q.2
The sludge does not contain waste water from
Q.3
Dry weather flow is:
Q.4
Drop manholes at the junctions of sewer lines, are provided if
Q.5
It is customary to design a sewer for D.W.F. on the basis of
Q.6
Maximum permissible velocity 1.5 m/sec, is adopted in drains
Q.7
Aerobic bacterias
Q.8
The quantity of liquid waste which flows in sewers during the period of rainfall, is known
Q.9
The pH value of sewage is determined with the help of
Q.10
In trickling filter, B.O.D. is reduced to
Q.11
The value of Chezy’s constant C = 157.6/(1.81 + K/ ) is used in
Q.12
The maximum spacing of manholes specified by Indian standard in sewers upto 0.3 m diameter is
Q.13
Dry water flow in a combined sewer, is
Q.14
A sewer running partially full and hurried with back filled, fails in compression due to
Q.15
The amount of oxygen consumed by the aerobic bacterias which cause the aerobic biological decomposition of sewage, is known
Q.16
Removal of oil and grease from sewage, is known
Q.17
If the depletion of oxygen is found to be 5 ppm after incubating a 2.5% solution of sewage sample for 5 days at 21°C, B.O.D. of the sewage is
Q.18
If the discharge of a sewer running half is 628 1.p.s., i = 0.001, and n = 0.010, the diameter of the sewer, is
Q.19
Acid regression stage of sludge digestion at a temperature 21°C extends over a period of
Q.20
The ratio of design discharge to the surface area of a sedimentation tank is called
Q.21
The maximum depth of sedimentation tanks, is kept
Q.22
Are available in size Stoneware sewers
Q.23
Oxidation process results in the formation of
Q.24
The spacing of man holes along a straight portion of a sewer is 300 m, the diameter of the sewer may be
Q.25
For non-scouring velocity 5 m/sec, the type of sewers generally preferred to, is
Q.26
A manhole is generally provided at each
Q.27
A sewer pipe contains 1 mm sand particles of specific gravity 2.65 and 5 mm organic particles of specific gravity 1.2, the minimum velocity required for removing the sewerage, is
Q.28
Dilution method of disposing of sewage, is not preferred to
Q.29
In case of Imhoff tanks,
Q.30
Chlorination of water is done for the removal of
Q.31
In a sludge digestion tank if the moisture content of sludge V1 litres is reduced from p1 % to p2 % the volume V2 is
Q.32
The minimum diameter of sewer to be adopted is
Q.33
In a grit chamber of a sewage treatment plant,
Q.34
Clogging of sewers, is caused due to
Q.35
A rainfall may be classified as acidic if its pH value is less or equal to
Q.36
If a 2% solution of sewage sample is incubated for 5 days at 20°C and the dissolved oxygen depletion was found to be 8 mg/l. The BOD of the sewage is
Q.37
If 2% solution of a sewage sample is incubated for 5 days at 20°C and depletion of oxygen was found to be 5 ppm, B.O.D. of the sewage is
Q.38
If the depletion of oxygen is found to be 2.5 mg/litre after incubating 2.5 ml of sewage diluted to 250 ml for 5 days at 20°C, B.O.D. of the sewage is
Q.39
R.M.O. expenses include
Q.40
15 cumecs, the depth d and width are related by For drains up to
Q.41
In a trickling filter
Q.42
In very first stage of decomposition of the organic matter in sewage
Q.43
The layers of vegetable wastes and night soil alternatively piled above the ground to form a mound, is called
Q.44
The settling velocity of the particles larger than 0.06 mm in a settling tank of depth 2.4 is 0.33 m per sec. The detention period recommended for the tank, is
Q.45
The discharge per unit plan area of a sedimentation tank, is generally called
Q.46
The recommended detention period for grit chambers is
Q.47
Fresh sewage is generally
Q.48
The sewage is pumped up
Q.49
The rainfall at any place may be determined by
Q.50
The clarigesters are
0 h : 0 m : 1 s