The term reactor referred to in waste water treatment is – (1) Vessel (2) Settling tank (3) Clarifier (4) Aeration tank

The term reactor referred to in waste water treatment is – (1) Vessel (2) Settling tank (3) Clarifier (4) Aeration tank
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(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 treated water (effluent) flowing out the other. While one tank is in settle/ decant mode the other is aerating and filling.
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The term reactor referred to in waste water treatment is (1) Vessel (2) Settling tank (3) Clarifier (4) Aeration tank

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

The flow of water gets retarded, in (A) Settling tank (B) Sedimentation tank (C) Clarifier (D) All the above

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

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

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)

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

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

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

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

Replenishment of dissolved oxygen in water stream polluted with industrial waste occurs by (A) Natural aeration of water stream (B) Photosynthetic action of algae (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Replenishment of dissolved oxygen in water stream polluted with industrial waste occurs by (A) Natural aeration of water stream (B) Photosynthetic action of algae (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

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 : 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

Last Answer : (D) All the above

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)

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) 

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 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

Last Answer : ANS: D

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

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

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 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

Last Answer : ANS: D

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)

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

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 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

Last Answer : ANS: D

Gravity settling process is not involved in the working of a (A) Hydrocyclone (B) Classifier (C) Dorr-thickener (D) Sedimentation tank

Description : Gravity settling process is not involved in the working of a (A) Hydrocyclone (B) Classifier (C) Dorr-thickener (D) Sedimentation tank

Last Answer : (A) Hydrocyclone

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 : 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

Last Answer : (D) All the above

Pick out the false statement pertaining to water treatment(A) Aeration of water is effective in CO2removal(B) The zeolite water softening process reduces the hardness of water by notmore than 50%(C) Sodium sulphate or sodium carbonate do not cause hardness in water(D) Water with pH value less than 7, is acidic.

Description : Pick out the false statement pertaining to water treatment. (A) Aeration of water is effective in CO2 removal (B) The zeolite water softening process reduces the hardness of water by not more than 50% (C ... carbonate do not cause hardness in water (D) Water with pH value less than 7, is acidic

Last Answer : (B) The zeolite water softening process reduces the hardness of water by not more than 50%

Reactors in commercial nuclear power plants in the U.S. are often referred to as thermal reactors. A thermal reactor uses: w) fissionable plutonium-239 as fuel. x) a relatively low heat output. y) neutrons moderated to relatively low energies. z) liquid sodium as a coolant.

Description : Reactors in commercial nuclear power plants in the U.S. are often referred to as thermal reactors. A thermal reactor uses: w) fissionable plutonium-239 as fuel. x) a relatively low heat output. y) neutrons moderated to relatively low energies. z) liquid sodium as a coolant.

Last Answer : ANSWER: Y -- NEUTRONS MODERATED TO RELATIVELY LOW ENERGIES.

The domestic sewage in large cities (a) has a high BOD as it contains both aerobic and anaerobic bacteria (b) is processed by aerobic and then anaerobic bacteria in the secondary treatment in Sewage Treatment Plants (STPs) (c) when treated in STPs does not really require the aeration step as the sewage contains adequate oxygen (d) has very high amount of suspended solids and dissolved salts.

Description : The domestic sewage in large cities (a) has a high BOD as it contains both aerobic and anaerobic bacteria (b) is processed by aerobic and then anaerobic bacteria in the secondary treatment in ... sewage contains adequate oxygen (d) has very high amount of suspended solids and dissolved salts.

Last Answer : (b) is processed by aerobic and then anaerobic bacteria in the secondary treatment in Sewage Treatment Plants (STPs)

(1) waste water released from kitchen Explanation: Sullage is a term used to descibe wastewater that wises as a byproduct of daily human activities such as showering, washing kitchen utensils, and doing the laundry. It is used water that does not contain excreta. Sullage is commonly referred to as gray water that is a mixture of water, soap, detergent, bleach, dirt, and other compounds discarded after use.

Description : (1) waste water released from kitchen Explanation: Sullage is a term used to descibe wastewater that wises as a byproduct of daily human activities such as showering, washing kitchen utensils, and doing ... a mixture of water, soap, detergent, bleach, dirt, and other compounds discarded after use.

Last Answer : A solution is - (1) a homogeneous mixture of two or more substances (2) a solid dissolved in a liquid (3) a solid dissolved i water (4) a mixture of two liquids

i used a whole bottle of clarifier and my pool is still cloudy. What do i do now?

Description : i used a whole bottle of clarifier and my pool is still cloudy. What do i do now?

Last Answer : My best friend is a pool guy. He has always told me that if still cloudy after clarifier, your pool is in shock. You don't add any chemicals, just backwash and rinse daily. He also said that it ... feet around the perimeter of the pool. throw another cup in the center of the pool. worked for mine.

Moisture can be removed from lubricating oil using (A) Tubular centrifuge (B) Clarifier (C) Sparkler filter (D) Vacuum leaf filter

Description : Moisture can be removed from lubricating oil using (A) Tubular centrifuge (B) Clarifier (C) Sparkler filter (D) Vacuum leaf filter

Last Answer : (A) Tubular centrifuge

To remove dirt from the flowing fluid, we use a (A) Coagulant (B) Gravity settler (C) Strains (D) Clarifier

Description : To remove dirt from the flowing fluid, we use a (A) Coagulant (B) Gravity settler (C) Strains (D) Clarifier

Last Answer : (C) Strains

__________ 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

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

Sediment and microorganisms can be removed centrifugally in a ____. a. tube c. pan b. clarifier d. box

Description : Sediment and microorganisms can be removed centrifugally in a ____. a. tube c. pan b. clarifier d. box

Last Answer : b. clarifier

What device is used to remove sulfur dioxide from power plant stack gases? w) scrubber x) precipitator y) digester z) clarifier

Description : What device is used to remove sulfur dioxide from power plant stack gases? w) scrubber x) precipitator y) digester z) clarifier

Last Answer : ANSWER: W -- SCRUBBER

Polymerisation reactor used for the production of styrene butadiene rubber (SBR) is made of (A) Cast iron (B) Stainless steel or glass lined vessel (C) Karbate (D) Wrought iron

Description : Polymerisation reactor used for the production of styrene butadiene rubber (SBR) is made of (A) Cast iron (B) Stainless steel or glass lined vessel (C) Karbate (D) Wrought iron

Last Answer : (B) Stainless steel or glass lined vessel

Multistage operation (as in the case of catalytic oxidation of SO2 ) is not carried out for NH3 synthesis, because of (A) Comparatively higher pressure drop (B) High cost of the high pressure vessel used for the reactor (C) Higher pumping cost (D) Chances of entrainment and disturbance of catalyst bed

Description : Multistage operation (as in the case of catalytic oxidation of SO2 ) is not carried out for NH3 synthesis, because of (A) Comparatively higher pressure drop (B) High cost of the high pressure ... for the reactor (C) Higher pumping cost (D) Chances of entrainment and disturbance of catalyst bed

Last Answer : (B) High cost of the high pressure vessel used for the reactor

Pick out the correct statement. (A) A lower temperature favours the reaction of lower activation energy (B) The dispersion number for a reactor/vessel is uL/D (C) The rate controlling step in a reaction involving many steps is the fastest step (D) Pore volume and porosity of a catalyst is measured by Brunauer￾Emmett-Teller (BET) technique

Description : Pick out the correct statement. (A) A lower temperature favours the reaction of lower activation energy (B) The dispersion number for a reactor/vessel is uL/D (C) The rate controlling step in ... step (D) Pore volume and porosity of a catalyst is measured by Brunauer￾Emmett-Teller (BET) technique

Last Answer : (A) A lower temperature favours the reaction of lower activation energy

Pick out the wrong statement. (A) In a batch reactor, which is exclusively used for liquid phase reactions; temperature pressure and composition may vary with time (B) In a semi-batch reactor, one reactant is charged batch wise, while the other reactant is fed continuously (C) In a continuous flow reactor, uniform concentration cannot be maintained throughout the vessel even in a well agitated system (D) In a continuous flow reactor, both the reactants and the products flow out continuously

Description : Pick out the wrong statement. (A) In a batch reactor, which is exclusively used for liquid phase reactions; temperature pressure and composition may vary with time (B) In a semi-batch reactor, ... system (D) In a continuous flow reactor, both the reactants and the products flow out continuously

Last Answer : (C) In a continuous flow reactor, uniform concentration cannot be maintained throughout the vessel even in a well agitated system

Pick out the wrong statement. (A) The vessel dispersion number (D/UL) for plug flow and mixed flow approaches zero and infinity respectively (B) Space time in a flow reactor is a measure of its capacity and is equal to the residence time when the density of reaction mixture is constant (C) Mixed reactor is always smaller than the plug flow reactor for all positive reaction orders for a particular duty (D) In an ideal tubular flow reactor, mixing takes place in radial direction and there is no mixing in longitudinal direction

Description : Pick out the wrong statement. (A) The vessel dispersion number (D/UL) for plug flow and mixed flow approaches zero and infinity respectively (B) Space time in a flow reactor is a ... ideal tubular flow reactor, mixing takes place in radial direction and there is no mixing in longitudinal direction

Last Answer : (C) Mixed reactor is always smaller than the plug flow reactor for all positive reaction orders for a particular duty

Stirred-tank bioreactors have been designed for (a) addition of preservatives to the product (b) purification of the product (c) ensuring anaerobic conditions in the culture vessel (d) availability of oxygen throughout the process.

Description : Stirred-tank bioreactors have been designed for (a) addition of preservatives to the product (b) purification of the product (c) ensuring anaerobic conditions in the culture vessel (d) availability of oxygen throughout the process.

Last Answer : (d) availability of oxygen throughout the process.

Stirred-tank bioreactors have been designed for (a) purification of product (b) addition of preservatives to the product (c) availability of oxygen throughout the process (d) ensuring anaerobic conditions in the culture vessel.

Description : Stirred-tank bioreactors have been designed for (a) purification of product (b) addition of preservatives to the product (c) availability of oxygen throughout the process (d) ensuring anaerobic conditions in the culture vessel.

Last Answer : (c) availability of oxygen throughout the process

An opening in the side of a tank or vessel such that the liquid surface with the tank is below the top edge of the opening, is called (A) Weir (B) Notch (C) Orifice(D) None of these

Description : An opening in the side of a tank or vessel such that the liquid surface with the tank is below the top edge of the opening, is called (A) Weir (B) Notch (C) Orifice (D) None of these

Last Answer : Answer: Option B

For a fluidised bed reactor, the most suitable/relevant model is a __________ model. (A) Tank in series (B) Bubbling bed (C) Plug flow (D) None of these

Description : For a fluidised bed reactor, the most suitable/relevant model is a __________ model. (A) Tank in series (B) Bubbling bed (C) Plug flow (D) None of these

Last Answer : (B) Bubbling bed

For nearly isothermal operation involving large reaction time in a liquid-phase reaction, the most suitable reactor is a __________ reactor. (A) Stirred tank (B) Tubular flow (C) Batch (D) Fixed bed

Description : For nearly isothermal operation involving large reaction time in a liquid-phase reaction, the most suitable reactor is a __________ reactor. (A) Stirred tank (B) Tubular flow (C) Batch (D) Fixed bed

Last Answer : (A) Stirred tank

Which of the following is an independent variable for a batch tank reactor with uniform concentration and temperature? (A) Time (B) Useful volume of the tank (C) Diameter of the reactor (D) None of these

Description : Which of the following is an independent variable for a batch tank reactor with uniform concentration and temperature? (A) Time (B) Useful volume of the tank (C) Diameter of the reactor (D) None of these

Last Answer : (A) Time

A backmix reactor (A) Is same as plug-flow reactor (B) Is same as ideal stirred tank reactor (C) Employs mixing in axial direction only (D) Is most suitable for gas phase reaction

Description : A backmix reactor (A) Is same as plug-flow reactor (B) Is same as ideal stirred tank reactor (C) Employs mixing in axial direction only (D) Is most suitable for gas phase reaction

Last Answer : (B) Is same as ideal stirred tank reactor

A reactor is generally termed as an autoclave, when it is a (A) High pressure batch reactor (B) Atmospheric pressure tank reactor (C) High pressure tubular reactor (D) Atmospheric pressure CSTR(

Description : A reactor is generally termed as an autoclave, when it is a (A) High pressure batch reactor (B) Atmospheric pressure tank reactor (C) High pressure tubular reactor (D) Atmospheric pressure CSTR

Last Answer : A) High pressure batch reactor

A back mix reactor is (A) Suitable for gas phase reactions (B) Ideal at very low conversion (C) Same as plug flow reactor (PFR) (D) Same as ideal stirred tank reactor

Description : A back mix reactor is (A) Suitable for gas phase reactions (B) Ideal at very low conversion (C) Same as plug flow reactor (PFR) (D) Same as ideal stirred tank reactor

Last Answer : (D) Same as ideal stirred tank reactor

Which of the following is the most suitable for very high pressure gas phase reaction? (A) Batch reactor (B) Tubular flow reactor (C) Stirred tank reactor (D) Fluidised bed reactor

Description : Which of the following is the most suitable for very high pressure gas phase reaction? (A) Batch reactor (B) Tubular flow reactor (C) Stirred tank reactor (D) Fluidised bed reactor

Last Answer : (B) Tubular flow reactor

In a continuous flow stirred tank reactor, the composition of the exit stream (A) Is same as that in the reactor (B) Is different than that in the reactor (C) Depends upon the flow rate of inlet stream (D) None of these

Description : In a continuous flow stirred tank reactor, the composition of the exit stream (A) Is same as that in the reactor (B) Is different than that in the reactor (C) Depends upon the flow rate of inlet stream (D) None of these

Last Answer : (A) Is same as that in the reactor

Pick out the wrong statement. (A) For a first order consecutive reaction, a tubular flow reactor as compared to a stirred tank reactor provides higher overall selectivity(B) For an ideal mixed reactor at steady state, the exit stream has the samecomposition as fluid within the reactor and the space time is equivalent toholding time for constant density system(C) Plug flow reactor (PFR) is always smaller than mixed reactor for allpositive reaction orders for a particular duty(D) Reaction rate does not decrease appreciably as the reaction proceeds incase of an autocatalytic reaction

Description : Pick out the wrong statement. (A) For a first order consecutive reaction, a tubular flow reactor as compared to a stirred tank reactor provides higher overall selectivity(B) For an ideal ... D) Reaction rate does not decrease appreciably as the reaction proceeds in case of an autocatalytic reaction

Last Answer : (A) For a first order consecutive reaction, a tubular flow reactor as compared to a stirred tank reactor provides higher overall selectivity

The conversion XA and residence time data are collected for zero order liquid phase reaction in a stirred tank reactor. Which of the following will be a straight line? (A) XA Vs . τ (B) XA Vs ln τ (C) XA /(1 - XA )Vs τ (D) XA (1 - XA )Vs τ

Description : The conversion XA and residence time data are collected for zero order liquid phase reaction in a stirred tank reactor. Which of the following will be a straight line? (A) XA Vs . τ (B) XA Vs ln τ (C) XA /(1 - XA )Vs τ (D) XA (1 - XA )Vs τ

Last Answer : (A) XA Vs . τ

For the same residence time, which one will give the maximum conversion? (A) Single stirred tank (v = 5 litres) (B) Two stirred tank (each of 2.5 litres) in series (C) Stirred tank followed by tubular flow reactor (each of 2.5 litres) (D) Single tubular flow reactor (v = 5 litres)

Description : For the same residence time, which one will give the maximum conversion? (A) Single stirred tank (v = 5 litres) (B) Two stirred tank (each of 2.5 litres) in series (C) Stirred tank followed by tubular flow reactor (each of 2.5 litres) (D) Single tubular flow reactor (v = 5 litres)

Last Answer : (D) Single tubular flow reactor (v = 5 litres)

A stirred tank reactor compared to tubular-flow reactor provides (A) More uniform operating conditions (B) Permits operation at the optimum temperature for a long reaction time (C) Higher overall selectivity for a first order consecutive reaction (D) All (A), (B) and (C

Description : A stirred tank reactor compared to tubular-flow reactor provides (A) More uniform operating conditions (B) Permits operation at the optimum temperature for a long reaction time (C) Higher overall selectivity for a first order consecutive reaction (D) All (A), (B) and (C

Last Answer : (D) All (A), (B) and (C

In the activated sludge process A. Aeration is continued till stability B. Aeration is done with an admixture of previously aerated sludge C. Sludge is activated by constant stirring D. Water is removed by centrifugal action

Description : In the activated sludge process A. Aeration is continued till stability B. Aeration is done with an admixture of previously aerated sludge C. Sludge is activated by constant stirring D. Water is removed by centrifugal action

Last Answer : ANS: B

Removal of __________ is accomplished by aeration of water. (A) Dissolved gases (B) Suspended solids (C) Dissolved solids (D) None of these

Description : Removal of __________ is accomplished by aeration of water. (A) Dissolved gases (B) Suspended solids (C) Dissolved solids (D) None of these

Last Answer : (A) Dissolved gases

Infective bacteria in water is killed by the __________ process. (A) Sterilisation (B) Aeration (C) Disinfection (D) None of these

Description : Infective bacteria in water is killed by the __________ process. (A) Sterilisation (B) Aeration (C) Disinfection (D) None of these

Last Answer : (A) Sterilisation

Aeration of water is done to remove (A) Odour (B) Colour (C) Bacterias (D) Turbidity

Description : Aeration of water is done to remove  (A) Odour  (B) Colour  (C) Bacterias  (D) Turbidity 

Last Answer : (A) Odour