A. acidic and alkaline
B. alkaline and acidic
C. both acidic
D. both alkaline
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 - Septic tank is a______________?
1) settling tank
2) digestion tank
3) aeration tank
The correct answer is?A. only (1)
B. (1) and (2)
C. (1) and (3)
D. only (3) - The percentage of chlorine in fresh bleaching powder is about________________?
A. 10 to 15
B. 20 to 25
C. 30 to 35
D. 40 to 50 - A pipe conveying sewage from plumbing system of a single building to common sewer or point of immediate disposal is called________________?
A. house sewer
B. lateral sewer
C. main sewer
D. submain sewer - 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 - Sewage treatment units are normally designed for______________?
A. 5-10 years
B. 15-20 years
C. 30-40 years
D. 40-50 years - 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 - Most of the bacteria in sewage are______________?
A. parasitic
B. saprophytic
C. pathogenic
D. anaerobic - 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
