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

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. 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

3. To test chemical oxygen demand (C.O.D.) of sewage, organic matter is oxidised by potassium dichromate in the presence of_______________?

   A. Hydrochloric acid
   B. Sulphuric acid
   C. Nitric acid
   D. Citric acid

4. In sewage having fully oxidised organic matter, the nitrogen exists in the form of________________?

   A. Nitrites
   B. Nitrates
   C. Free ammonia
   D. Aluminoid nitrogen

5. For the COD test of sewage, organic matter is oxidised by K2Cr2O7 in the presence of________________?

   A. H2SO4
   B. HNO3
   C. HCl
   D. None of these

6. 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_________________?

   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

7. 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

8. A sewer pipe contains 1 mm sand particles of specific gravity 2.65 and 5 mm organic particles of specific gravity 1.2, the minimum velocity required for removing the sewerage, is_____________________?

   A. 0.30 m/sec
   B. 0.35 m/sec
   C. 0.40 m/sec
   D. 0.45 m/sec

9. The disintegrating pump in which solid matter is broken up before passing out, is__________________?

   A. Centrifugal pump
   B. Reciprocating pump
   C. Pneumatic ejector
   D. None of these

10. The non-clog pump which permits solid matter to pass out with the liquid sewage, is________________?

    A. Centrifugal pump
    B. Reciprocating pump
    C. Pneumatic ejector
    D. None of these