Related Questions

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
During sewage treatment, the sewage is subjected to __________ treatment in Imhoff tank.
A Filtration
B Digestion
C Sedimentation
D Both B and C
Which one of the following statements regarding septic tanks is wrong?
A A gap of 7.5 cm between the bottom of the covering slab and the top level of scum is provided
B The outlet invert level is kept 5 to 7.5 cm below the inlet invert level
C The minimum width of septic level is 90 cm
D The depth of tank is kept equal to its width
Septic tanks are used for the __________ of the deposited solids.
A Separation
B Anaerobic decomposition
C Aerobic decomposition
D None of these
In septic tanks,
A Free board of 0.3 m may be provided
B The baffles or tees are extended up to top level of scum
C The clear space between the baffle top and covering slab is about 7.5 cm
D All the above
The rate of accumulation of sludge in septic tanks is recommended as
A 30 litres/person/year
B 25 litres/person/year
C 30 litres/person/month
D 25 litres/person/month
The digested sludge from septic tanks, is removed after a maximum period of
A 3 years
B 3.5 years
C 4 years
D 5 years
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
Fine grit present in sewage is removed in the __________ during sewage treatment.
A Grit chamber
B Detritus tank
C Trickling filter
D Skimming tank
__________ substances present in sewage are removed in grit chamber during sewage treatment.
A Organic
B Fatty
C Inorganic
D Dissolved

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