A shallow pond in which the sewage is retained and biologically treated is called__________________?

Related Mcqs:

1. Fine grit present in sewage is removed in the _____________ during sewage treatment?

   A. Grit chamber
   B. Detritus tank
   C. Trickling filter
   D. Skimming tank

2. During sewage treatment, the sewage is subjected to ______________ treatment in Imhoff tank?

   A. Filtration
   B. Digestion
   C. Sedimentation
   D. Both B. and C.

3. ____________ substances present in sewage are removed in grit chamber during sewage treatment?

   A. Organic
   B. Fatty
   C. Inorganic
   D. Dissolved

4. There are thirteen metals which are treated as pollutants. Which of the following metals is not a pollutant ?

   A. Mercury
   B. Arsenic
   C. Aluminium
   D. Lead

5. Coal washing waste water containing about 3% suspended solids (comprising of clay, slate, stone etc.) is treated for solid particles removal ?

   A. By chemical coagulation
   B. In sedimentation tanks equipped with mechanical scrapper
   C. In vacuum filter
   D. In clarifiers

6. Maximum permissible residual chlorine in treated water should be ____________ mg/litre?

   A. 0.001 to 0.01
   B. 0.2 to 0.3
   C. 2 to 3
   D. 5 to 10

7. The amount of chemical coagulant added for treatment of polluted water ______________ with increase in temperature of the polluted water to be treated?

   A. Decreases
   B. Increases
   C. Remain constant
   D. May increase or decrease; depends on the chemical characteristics of polluted water

8. The function of skimming tank in sewage treatment is to remove _____________ substances?

   A. Dissolved solid
   B. Suspended solid
   C. Oil & fatty
   D. Gritty & inorganic

9. COD of raw municipal sewage may be in the range of about _____________ mg/litre?

   A. 1-2
   B. 5-10
   C. 90-120
   D. 1500-2500

10. The pH value of oxidised sewage is about_____________________?

    A. 1.8
    B. 6.2
    C. 7.3
    D. 13.4