Assertion A. : Discharging the effluents from the oxidation ponds just up stream of lakes or reservoirs is undesirable. Reason (R) : The discharged algae get settled in the reservoirs and cause anaerobic decomposition and other water qualities_________________?

Related Mcqs:

1. The sewage treatment units in which anaerobic decomposition of organic matter is used, are called________________?

   A. Imhoff tanks
   B. Trickling filters
   C. Sludge sedimentation tanks
   D. None of these

2. Assertion A.: The determination of pH value of sewerage is important. Reason (R): The efficiency of certain treatment methods depends upon the availability of pH value________________?

   A. Both A and R are true and R is the correct explanation of A
   B. Both A and R are true but R is not a correct explanation of A
   C. A is true but R is false
   D. A is false but R is true

3. Assertion A.: The minimum self cleansing velocity in the sewer, at least once a day, must be generated. Reason (R): If certain deposition takes place and is not removed, it obstructs free flow and causes further deposition leading to complete blocking of the sewer?

   A. Both A and R are true and R is the correct explanation of A
   B. Both A and R are true but R is not a correct explanation of A
   C. A is true but R is false
   D. A is false but R is true

4. Assertion A.: A free board of 0.3 m is provided above the top sewage line in septic tanks. Reason (R): It helps to accommodate the scum in the septic tank_________________?

   A. Both A and R is true and R is the correct explanation of A
   B. Both A and R is true but R is not a correct explanation of A
   C. A is true but R is false
   D. A is false but R is true

5. The amount of oxygen consumed by the aerobic bacterias which cause the aerobic biological decomposition of sewage, is known_________________?

   A. Bio-Chemical Oxygen Demand (B.O.D.)
   B. Dissolved Oxygen (D.O.)
   C. Chemical Oxygen Demand (C.O.D.)
   D. None of these

6. Before discharging the foul sewage into rivers, it is generally treated by_____________________?

   A. Screening
   B. Sedimentation
   C. Oxidation
   D. All the above

7. The width of a rectangular sewer is twice its depth while discharging 1.5 m/sec. The width of the sewer is______________?

   A. 0.68 m
   B. 0.88 m
   C. 1.36 m
   D. 1.76 m

8. The algae dies out in the zone of_____________________?

   A. Degradation
   B. Active decomposition
   C. Recovery
   D. Cleaner water

9. In very first stage of decomposition of the organic matter in sewage________________?

   A. Nitrites are formed
   B. Nitrates are formed
   C. Carbondioxide is formed
   D. Ammonia is formed

10. In septic tanks, decomposition of organic bacteria, is done by_____________________?

    A. Anaerobic bacteria
    B. Aerobic bacteria
    C. Both types of bacterias
    D. None of these