A. The presence of oxygen
B. The absence of oxygen
C. Both cases A. and B.
D. Neither A. nor B.
Related Mcqs:
- 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 - Aerobic bacterias___________________?
A. Flourish in the presence of free oxygen
B. Consume organic matter as their food
C. Oxidise organic matter in sewage
D. All the above - The sludge does not contain waste water from_________________?
A. Bath rooms
B. Wash basins
C. Kitchen sinks
D. Toilets - 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 - The design period in years for pumping plants, is___________________?
A. 1
B. 2 to 3
C. 3 to 5
D. 5 to 10 - A rain sanitary sewer is constructed to carry_________________ ?
A. Sanitary sewage
B. Storm sewage
C. Surface water
D. Ground water - 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 - Flocculated particles do not change their___________________?
A. Size
B. Shape
C. Weight
D. None of these - 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 - Pick up the correct statement from the following?
A. Indore method of composting involves decomposition under aerobic conditions
B. Bangalore method of composting involves decomposing under anaerobic conditions
C. Fully stabilised refuse by the Bangalore method of compositing is a powdery mass called humus
D. all of these
