Description : Dorr thickener is an equipment used for (A) Classification (B) Sedimentation (C) Clarification (D) Leaching
Last Answer : (B) Sedimentation
Description : Which is the most efficient dust removal equipment for removal of submicronic dust particles from blast furnace gas? (A) Packed scrubber (B) Gravity settling chamber (C) Electrostatic precipitator (D) Hydrocyclone
Last Answer : (C) Electrostatic precipitator
Description : Suspended solid present in the waste water generated in blast furnace gas cooling and cleaning plant is removed by (A) Biological oxygen pond (B) Radial settling tank (thickener) using coagulant (lime & ferrous sulphate) (C) Lagoons (D) Filtration
Last Answer : (B) Radial settling tank (thickener) using coagulant (lime & ferrous sulphate)
Description : Which of the following is not a wet classifier? (A) Sharpies super-centrifuge (B) Hydrocyclones (C) Dorr Oliver rake classifier (D) None of these
Last Answer : (D) None of these
Description : __________ employs a set of screen across a flow channel for the separation of dirt/rust from a flowing liquid stream. (A) Thickener (B) Classifier (C) Strainer (D) Clarifier
Last Answer : (C) Strainer
Description : In a sedimentation tank (length L, width B, depth D) the settling velocity of a particle for a discharge Q, is A. Q/(B × D) B. Q/(L × D) C. Q/L D. Q/(B × L)
Last Answer : ANS: D
Description : The flow of water gets retarded, in (A) Settling tank (B) Sedimentation tank (C) Clarifier (D) All the above
Last Answer : (D) All the above
Description : If L, B and D length, breadth and depth of water in a rectangular sedimentation tank of total discharge Q, the settling velocity, is (A) Q/H (B) Q/D (C) Q/(D × B) (D) Q/(L × B)
Last Answer : (D) Q/(L × B)
Description : Which of the following is a batch sedimentation equipment? (A) Dust catcher (B) Filter thickener (C) Dry cyclone separator (D) Rotary sprayer scrubber
Last Answer : (B) Filter thickener
Description : Pick out the wrong statement pertaining to leaching. (A) Fine solids cannot be leached in a Pachuca tank (B) Door classifier can be used for leaching of coarse solids (C) Vegetable seeds can be ... , Rotocel or Kennedy extractor (D) Very high temperature is not needed for the leaching of sugar beet
Last Answer : (A) Fine solids cannot be leached in a Pachuca tank
Description : Distribution of wash water is provided in (A) Sedimentation tank (B) Slow sand filter (C) Rapid gravity filter (D) All the above
Last Answer : (C) Rapid gravity filter
Description : If a force greater than that of gravity is used to separate solids & fluidsof different densities, the process is termed as the (A) Sedimentation (B) Flocculation (C) Dispersion (D) Centrifugation
Last Answer : (D) Centrifugation
Description : During sewage treatment, effluent from which one of the following treatment units has minimum wt/vol amount of suspended solids? (a) Detritus channel (b) Primary sedimentation tank (c) Secondary sedimentation tank (d) Activated sludge process aeration tank
Last Answer : (d) Activated sludge process aeration tank
Description : Two particles are called to be equal settling, if they are having the same. (A) Size (B) Specific gravity (C) Terminal velocities in the same fluid & in the same field of force (D) None of these
Last Answer : (C) Terminal velocities in the same fluid & in the same field of force
Description : The most efficient equipment for the removal of sub-micronic dust particles from blast furnace gas is the (A) Venturi atomiser (B) Gravity settling chamber (C) Electro-static precipitator (D) Cyclone separator
Last Answer : (C) Electro-static precipitator
Description : Particle size range in which dust catcher (gravity settling chamber) works most effectively and efficiently is __________ microns. (A) < 5 (B) 10 to 25 (C) < 74 (D) > 1000
Last Answer : (C) < 74
Description : A particle A of diameter 10 microns settles in an oil of specific gravity 0.9 and viscosity 10 poise under Stoke's law. A particle B with diameter 20microns settling in the same oil will have a settling velocity (A) ... ) One fourth as that of A (C) Twice as that of A (D) Four times as that of A
Last Answer : (B) One fourth as that of A
Description : Most efficient and suitable dust removal equipment for removal of flyash from flue gas in a thermal power plant is the (A) Gravity settling chamber (B) Cyclone separator (C) Electrostatic precipitator (D) Bag filter
Description : Which of the following does not discharge the dust collected as a dry solid? (A) Electrostatic precipitator (B) Wet scrubber (C) Bag filter (D) Gravity settling chamber
Last Answer : (B) Wet scrubber
Description : Which of the following is the most efficient for removal of very finely divided suspended solids and colloidal matter from the polluted waterstream? (A) Sedimentation tank (B) Circular clarifier (C) Mechanical flocculation (D) Chemical coagulation
Last Answer : (D) Chemical coagulation
Description : During sewage treatment, the sewage is subjected to __________ treatment in Imhoff tank. (A) Filtration (B) Digestion (C) Sedimentation (D) Both (B) and (C)
Last Answer : (D) Both (B) and (C)
Description : In a sedimentation tank, the detention period for water ranges from __________ hours. (A) 2 to 4 (B) 8 to 12 (C) 16 to 20 (D) 24 to 32
Last Answer : (A) 2 to 4
Description : The term reactor referred to in waste water treatment is – (1) Vessel (2) Settling tank (3) Clarifier (4) Aeration tank
Last Answer : (4) Aeration tank Explanation: Reactors are industrial processing tanks for the treatment of wastewater. The tanks have a "flow through" system, with raw wastewater (influent) coming in at one end and ... out the other. While one tank is in settle/ decant mode the other is aerating and filling.
Description : The dimensions of a rectangular settling tank are: length 24 m, width 6 m and depth 3 m. If 2 hour detention period for tanks is recommended, the rate of flow of sewage per hour, is A. 204 cu.m B. 208 cu.m C. 212 cu.m D. 216 cu.m
Description : The detention time (t) of a settling tank, may be defined as the time required for A. A particle to travel along its length B. A particle to travel from top surface to bottom sludge zone C. The flow of sewage to fill the tank D. None of these
Last Answer : ANS: C
Description : The width of a settling tank with 2 hour detention period for treating sewage 378 cu m per hour, is A. 5 m B. 5.5 m C. 6.5 m D. 7 m
Description : 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 A. 30 minutes B. 1 hour C. 1 hour and 30 minutes D. 2 hours
Description : The ratio of discharge and plan area of a continuous flow type settling tank, is known (A) Surface loading (B) Overflow (C) Overflow rate (D) All the above
Description : Detention period of a settling tank is (A) Average theoretical time required for water to flow through the tank (B) Time required for flow of water to fill the tank fully (C) Average time for which water is retained in tank (D) All the above
Description : The term reactor referred to in waste water treatment is (1) Vessel (2) Settling tank (3) Clarifier (4) Aeration tank
Last Answer : Aeration tank
Description : __________ is used for producing a thick suspension from a thin slurry. (A) Cartridge filter (B) Rotary drum vacuum filter (C) Pressure filter thickener (D) Plate and frame filter press
Last Answer : (C) Pressure filter thickener
Description : Gravity settling tanks/porous filters are used to remove particles larger than
Last Answer : Gravity settling tanks/porous filters are used to remove particles larger than A. `2 mum ` B. `50 mum` C. `20 mum` D. `10 mum`
Description : If the specific gravity of a soil particle of 0.05 cm diameter is 2.67, its terminal velocity while settling in distilled water of viscosity, 0.01 poise, is (A) 0.2200 cm/sec (B) 0.2225 cm/sec (C) 0.2250 cm/sec (D) 0.2275 cm/sec
Last Answer : (D) 0.2275 cm/sec
Description : The function of sedimentation tank in sewage treatment is to: (1) Disinfect the sewage (2) Remove water content (3) Aerate the sewage (4) Remove suspended solids
Last Answer : (4) Remove suspended solids Explanation: The function of sedimentation tank in the sewage treatment is to remove suspended solids.
Description : The ratio of design discharge to the surface area of a sedimentation tank is called A. Surface loading B. Overflow rate C. Overflow velocity D. All of these
Description : The settlement of a particle in sedimentation tank, is affected by A. Velocity of flow B. Viscosity of water C. Size and shape of solid D. All the above
Description : For treating the sewage of a large city, you will recommend A. A sedimentation tank and an activated sludge treatment plant B. A plant consisting of Imhoff tanks with low rate trickling filters C. Sedimentation tanks with high rate trickling filters D. None of these
Last Answer : ANS: A
Description : The discharge per unit plan area of a sedimentation tank, is generally called A. Over flow rate B. Surface loading C. Over flow velocity D. All the above
Description : For a continuous flow type of sedimentation tanks A. Width of the tank is normally kept about 6 m B. Length of the tank is normally kept 4 to 5 times the width C. Maximum horizontal flow velocity is limited to 0.3 m/minute D. All the above
Last Answer : D
Description : Normal values of overflow rate for plain sedimentation tank using coagulants, is (A) 750 to 1000 litres/hr/m2 (B) 1000 to 1250 litres/hr/m2 (C) 1250 to 1500 litres/hr/m2 (D) 1500 litres/hr/m
Last Answer : (B) 1000 to 1250 litres/hr/m2
Description : Detention time for plain sedimentation tank usually ranges from (A) 2 to 4 hours (B) 4 to 8 hours (C) 6 to 10 hours (D) 8 to 12 hours
Last Answer : (B) 4 to 8 hours
Description : Velocity of flow of water in plain sedimentation water tank, is normally kept (A) 3 cm/minute (B) 10 cm/minute (C) 20 cm/minute (D) 30 cm/minute
Last Answer : (D) 30 cm/minute
Description : The efficiency of sedimentation tank does not depend upon (A) Depth of tank (B) Length of tank (C) Detention period (D) Velocity of water
Last Answer : (D) Velocity of water
Description : Normal values of overflow rate for plain sedimentation tank, is (A) 250 to 500 litres/hr/m2 (B) 500 to 750 litres/hr/m2 (C) 750 to 1000 litres/hr/m2 (D) 1000 to 1250 litres/hr/m
Last Answer : (B) 500 to 750 litres/hr/m
Last Answer : Remove suspended solids
Description : Pick out the wrong statement. (A) Recycled coarse material to the grinder by a classifier is termed as circulating load (B) Wear and tear in wet crushing is more than that in dry crushing of ... a pipeline which permits the solids to settle down due to reduction in velocity of the dust laden gas
Last Answer : (C) Size enlargement (opposite of size reduction) is not a mechanical operation
Description : Pick out the wrong statement. (A) Close circuit grinding is more economical than open circuit grinding (B) Cod oil, beef tallow or aluminium stearates are used as grinding aids in cement ... is called a classifier (D) Size enlargement is a mechanical operation exemplified by medicinal tablet making
Last Answer : (C) The equipment used for the removal of traces of solids from a liquid is called a classifier
Description : The capacity of a classifier in 'tons of solid/hr' is given by (where, A = cross-sectional area in m2 , V = rising velocity of fluid in m/sec, S = percentage of solids in the suspension by volume, ρ = density of solids in kg/m3 ) (A) 3.6 AVS.ρ (B) 3.6 A.V.ρ (C) 3.6 A.S. ρ (D) 3.6 AVS/ρ
Last Answer : (A) 3.6 AVS.ρ
Description : Solid particles of different densities are separated by (A) Filters (B) Thickness (C) Cyclones (D) Sorting classifier
Last Answer : (D) Sorting classifier