The alum, when added as a coagulant in water_______________?

A. to increase the filtration slow sand filters capacity of
B. to increase the filtration rapid sand filters capacity of
C. for isolated buildings like pools, hotels etc swimming
D. all of the above

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

A. 50 to 60
B. 100 to 150
C. 500 to 600
D. 1400 to 1500