A. 0
B. 1
C. infinity
D. none of the above
Related Mcqs:
- In a BOD test, 1.0 ml of raw sewage was diluted to 100 ml and the dissolved oxygen concentration of diluted sample at the beginning was 6 ppm and it was 4 ppm at the end of 5 day incubation at 20°C. The BOD of raw sewage will be___________?
A. 100 ppm
B. 200 ppm
C. 300 ppm
D. 400 ppm - The specific gravity of sewage is_______________?
A. much greater than 1
B. slightly less than 1
C. equal to 1
D. slightly greater than 1 - The chemical most commonly used to increase speed of sedimentation of sewage is_______________?
A. sulphuric acid
B. copper sulphate
C. lime
D. sodium permanganate - Which of the following sewers is preferred for combined system of sewage ?
A. circular sewer
B. egg shaped sewer
C. rectangular sewer
D. none of the above - Most suitable section of sewer in separate sewage system is________________?
A. rectangular section
B. circular section
C. standard form of egg shaped sewer
D. modified egg shaped section - The relative stability of a sewage sample, whose dissolved oxygen is same as the total oxygen required to satisfy BOD, is______________?
A. 1
B. 100
C. infinite
D. zero - If the sewage contains grease and fatty oils, these are removed in_________________?
A. grit chambers
B. detritus tanks
C. skimming tanks
D. sedimentation tanks - In facultative stabilization pond, the sewage is treated by________________?
A. aerobic bacteria only
B. algae only
C. dual action of aerobic bacteria and anaerobic bacteria
D. sedimentation - Sewage treatment units are designed for_______________?
A. maximum flow only
B. minimum flow only
C. average flow only
D. maximum and minimum flow - The characteristics of fresh and septic sewage respectively are____________________?
A. acidic and alkaline
B. alkaline and acidic
C. both acidic
D. both alkaline
