500 Best Environmental Engineering- MCQ
Q117). In a rapid sand filter, the filter head varies from 1 to 1.5 m
a).1.5 to 2 m
b).2 to 4 m
c).4 to 5 m
d).2 to 4 m
Correct Answer:
Explanation:
Q118). Cleaning of rapid sand filters is done by
a).Scrapping the top layer of filter media
b).Back washing
c).Providing new sand layers
d).All of these
Correct Answer:
Back washing
Explanation:
Q119). Cleaing period for a rapid sand filter is taken as
a).2 to 3 hours
b).2 to 3 days
c).2 to 3 weeks
d).2 to 3 months
Correct Answer:
2 to 3 days
Explanation:
Q120). Rapid sand filter can remove bacterias upto an extent of
a).60 to 70%
b).70 to 80%
c).80 to 90%
d).90 to 99%
Correct Answer:
80 to 90%
Explanation:
Q121). Rapid sand filter can remove turbidity from water upto an extent of
a).15 to 25 ppm
b).25 to 35 ppm
c).35 to 40 ppm
d).40 to 50 ppm
Correct Answer:
35 to 40 ppm
Explanation:
Q122). Pressure filters are not used for treating municipal water supplies, because
a).The rate of filteration is high
b).The overall plant capacity is small
c).They are inefficient in the removal of turbidity and bacterias
d).They are more costly
Correct Answer:
They are more costly
Explanation:
Q123). Pressure filters are best suited for
a).Swimming pools
b).Railway stations
c).Individual industries
d).All of these
Correct Answer:
All of these
Explanation:
Q124). The process of killing pathogenic bacterias from water is called
a).Sedimentation
b).Filteration
c).Coagulation
d).Disinfection
Correct Answer:
Disinfection
Explanation: