Engineering Questions with Answers - Multiple Choice Questions
Environmental Engineering MCQ’s – Types of Sewage Filter
1 - Question
The intermittent sand filters have better BOD removal efficiency than trickling filters.
a) True
b) False
View Answer
Answer: b
Explanation: The trickling filters have the best BOD removal efficiency in comparison to the types of filters used in aerobic treatment with a maximum value of 95%.
2 - Question
The filter material used in contact bed is ___________
a) Sand
b) Stone ballast
c) Gravel
d) Fine sand
View Answer
Answer: b
Explanation: The filter material used in the contact bed is broken stones called as stone ballast.
3 - Question
Which of the following is called as contact bed?
a) Primary clarifier
b) Secondary clarifier
c) Contact filter
d) High rate digester
View Answer
Answer: c
Explanation: Contact filters are water tight tanks that are used for the aerobic treatment of sewage. They are also called as contact bed.
4 - Question
How many types of trickling filters are used in sewage treatment?
a) 6
b) 5
c) 3
d) 2
View Answer
Answer: d
Explanation: The trickling filters are divided into conventional and high rate trickling filters.
5 - Question
The depth of the filter media of intermittent filter is ___________
a) 45cm
b) 60cm
c) 20cm
d) 25cm
View Answer
Answer: b
Explanation: The minimum depth of filter media of intermittent filter is 60cm. These filters give highly nitrified effluent.
6 - Question
Which of the following filter is used in the anaerobic treatment of sewage?
a) Intermittent sand
b) Trickling filter
c) Contact filter
d) Biological filter
View Answer
Answer: d
Explanation: Biological filter is used in anaerobic treatment, whereas intermittent sand filter, trickling filter and contact filter are used in the aerobic treatment of sewage.
7 - Question
The maximum size of filter media of a percolating filter is ___________
a) 10mm
b) 25mm
c) 60mm
d) 75mm
View Answer
Answer: d
Explanation: The minimum and maximum size of filter media of a percolating filter is 25mm and 75mm respectively.
8 - Question
The recirculation ratio for the low rate trickling filter is ___________
a) 1
b) 2
c) 3
d) 0
View Answer
Answer: d
Explanation: The recirculation system is not provided in the low rate trickling filter. So, when the recirculation is 0, the type of filter used is a low rate trickling filter.