A. aerobic only
B. anaerobic only
C. aerobic in lower compartment and anaerobic in upper compartment
D. anaerobic in lower compartment and aerobic in upper compartment
Related Mcqs:
- The detention period in coagulation tanks is usually kept as_______________?
A. 1 to 2 minutes
B. 30 to 45 minutes
C. 2 to 6 hours
D. 2 to 6 days - The overflow rate for plain sedimentation tanks is about__________________?
A. 500 to 750 litres/hour/ m2
B. 1000 to 1250 litres/hour/ m2
C. 1250 to 1500 litres/hour/m2
D. 1500 to 2000 litres/hour/m2 - Which of the following unit works in anaerobic conditions ?
A. sludge digestion tank
B. sedimentation tank
C. activated sludge treatment
D. trickling filters - For normal sludge, the value of sludge index for Indian conditions is________________?
A. 0 to 50
B. 50 to 150
C. 150 to 350
D. 350 to 500 - For satisfactory working of a sludge digestion unit, the pH range of digested sludge should be maintained as___________________?
A. 4.5 to 6.0
B. 6.5 to 8.0
C. 8.5 to 10.0
D. 10.5 to 12.0 - The type of valve, which is provided on the suction pipe in a tube-well, is____________?
A. air relief valve
B. reflux valve
C. pressure relief valve
D. sluice valve - Scour valves are provided ______________?
A. at street corners to control the flow of water
B. at every depression and dead ends to drain out the waste water that may collect there
C. at the foot of rising main along the slope to prevent back running of water
D. at every summit of rising mains - The process of lagooning is primarily a means of________________?
A. reducing the excessive flow in sewers
B. disposing of sludge
C. increasing the capacity of storage re-servoirs
D. increasing flow of sewage through imhoff tanks - A sewer that receives the discharge of a number of house sewers is called________________?
A. house sewer
B. lateral sewer
C. intercepting sewer
D. submain sewer - Which of the following values of pH represents a stronger acid?
A. 2
B. 5
C. 7
D. 10
