The rate of accumulation of sludge in septic tanks is recommended as____________________?

Related Mcqs:

1. 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

2. The moisture content of sludge is reduced from 90% to 80% in a sludge digestion tank. The percentage decrease in the volume of sludge, is_______________?

   A. 25 %
   B. 50 %
   C. 10 %
   D. 5 %

3. The digested sludge from septic tanks, is removed after a maximum period of__________________?

   A. 3 years
   B. 3.5 years
   C. 4 years
   D. 5 years

4. The rate of accumulation of sludge per person per year, is_______________________?

   A. 10 litres
   B. 15 litres
   C. 20 litres
   D. 25 litres

5. In a sludge digestion tank if the moisture content of sludge V1 litres is reduced from p1 % to p2 % the volume V2 is____________________?

   A. [(100 + P1)/(100 – P2)] V1
   B. [(100 – P1)/(100 + P2)] V1
   C. [(100 – P1)/(100 – P2)] V1
   D. [(100 + P2)/(100 – P1)] V1

6. The bottom of the sewage inlet chamber of septic tanks, is provided an outward slope_________________?

   A. 1 in 5
   B. 1 in 10
   C. 1 in 15
   D. 1 in 20

7. 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

8. The sewage treatment in septic tanks is due to__________________?

   A. Anaerobic decomposition
   B. Aerobic decomposition
   C. Parasitic decomposition
   D. None of these

9. Which one of the following statements regarding septic tanks is wrong ?

   A. A gap of 7.5 cm between the bottom of the covering slab and the top level of scum is provided
   B. The outlet invert level is kept 5 to 7.5 cm below the inlet invert level
   C. The minimum width of septic level is 90 cm
   D. The depth of tank is kept equal to its width

10. 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