1. Some of the water quality parameters are measured by titrating a water sample with a titrant. Group I gives a list of parameters and Group II gives the list of titrants.
   

   Group I	Group II
   P. Alkalinity	1. N/35.5 AgNO3
   Q. Hardness	2. N/40 Na2 S2O3
   R. Chloride	3. N/50 H2SO4
   S. Dissolved oxygen	4. N/50 EDTA

   
   The correct match of water quality parameters in Group I with titrants in Group II is

1. 1. P-1, Q-2, R-3, S-4

   
   
   

   2. P-3, Q-4, R-1, S-2

   
   
   

   3. P-2, Q-1, R-4, S-3

   
   
   

   4. P-4, Q-3, R-2, S-1

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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2. The dominating microorganisms in an activated sludge process reactor are

1. 1. aerobic heterotrophs

   
   
   

   2. anaerobic heterotrophs

   
   
   

   3. autotrophs

   
   
   

   4. phototrophs

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

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3. The potable water is prepared from turbid surface water by adopting the following treatment sequence.

1. 1. Turbid surface water → Coagulation → Flocculation → Sedimentation → Filtration → Disinfection → Storage & Supply

   
   
   

   2. Turbid surface water → Disinfection → Flocculation → Sedimentation → Filtration → Coagulation → Storage & Supply

   
   
   

   3. Turbid surface water → Filtration → Sedimentation → Disinfection → Flocculation → Coagulation → Storage & Supply

   
   
   

   4. Turbid surface water → Sedimentation → Flocculation → Coagulation → Disinfection → Filtration → Storage & Supply

   
   
   

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1. View Hint View Answer Discuss in Forum

   Coagulation – flocculation process is always followed by Sedimentation and then filtration. Disinfection is the last process.

   Correct Option: D

   Coagulation – flocculation process is always followed by Sedimentation and then filtration. Disinfection is the last process.

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4. Some of the nontoxic metals normally found in natural water are

1. 1. arsenic, lead and mercury

   
   
   

   2. calcium, sodium and silver

   
   
   

   3. cadmium, chromium and copper

   
   
   

   4. iron, manganese and magnesium

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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5. Total Kjeldahl Nitrogen (TKN) concentration (mg/L as N) in domestic sewage is the sum of the concentrations of:

1. 1. Organic and inorganic nitrogen in sewage

   
   
   

   2. Organic nitrogen and nitrate in sewage

   
   
   

   3. Organic nitrogen and ammonia in sewage

   
   
   

   4. Ammonia and nitrate in sewage Problem Based MCQs

   
   
   

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1. View Hint View Answer Discuss in Forum

   T.KN = Ammonia (60%) + Organic Nitrogen (40%)

   Correct Option: C

   T.KN = Ammonia (60%) + Organic Nitrogen (40%)

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