The ratio of 5 day BOD to ultimate BOD is about_______________?

Related Mcqs:

1. In a BOD test, 1.0 ml of raw sewage was diluted to 100 ml and the dissolved oxygen concentration of diluted sample at the beginning was 6 ppm and it was 4 ppm at the end of 5 day incubation at 20°C. The BOD of raw sewage will be___________?

   A. 100 ppm
   B. 200 ppm
   C. 300 ppm
   D. 400 ppm

2. If Biochemical oxygen demand (BOD. of a town is 20000 kg/day and BOD per capita per day is 0.05 kg, then population equivalent of town is_________________?

   A. 1000
   B. 4000
   C. 100000
   D. 400000

3. Percentage of bacterial load that can be removed from water by the process of plain sedimentation is about_______________?

   A. 10 to 25
   B. 50
   C. 75
   D. 100

4. Standard BOD is measured at________________?

   A. 20°C – 1day
   B. 25°C- 3day
   C. 20°C – 5day
   D. 30°C- 5day

5. The rate of BOD exerted at any time is_____________?

   A. directly proportional to BOD satisfied
   B. directly proportional to BOD remain-ing
   C. inversely proportional to BOD satisfied
   D. inversely proportional to BOD re-maining

6. The relative stability of a sewage sample, whose dissolved oxygen is same as the total oxygen required to satisfy BOD, is______________?

   A. 1
   B. 100
   C. infinite
   D. zero

7. The maximum efficiency of BOD removal is achieved in______________?

   A. oxidation pond
   B. oxidation ditch
   C. aerated lagoons
   D. trickling filters

8. The correct relation between theoretical oxygen demand (TOD), Biochemical oxygen demand (BOD) and Chemical oxygen demand (COD) is given by_______________?

   A. TOD>BOD>COD
   B. TOD>COD>BOD
   C. BOD>COD>TOD
   D. COD>BOD>TOD

9. Sludge volume index is defined as the ratio of_______________?

   A. percentage of sludge by volume to percentage of suspended solids by weight
   B. percentage of sludge by volume to percentage of total solids by weight
   C. percentage of suspended solids by weight to percentage of sludge by volume
   D. percentage of total solids by weight to percentage of sludge by volume

10. Assertion A: Slow sand filters are more efficient in removal of bacteria than rapid sand filters. Reason R : The sand used in slow sand filters is finer than that in rapid sand filters. Select your answer based on the coding system given below?

    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 the correct explanation of A
    C. A is true but R is false
    D. A is false but R is true