Waste Water Treatment MCQ Questions - Set 16 - ObjectiveBooks

# Practice Test: Question Set - 16

1. For laying a sewer line in a trench of 2 m width, an offset line is marked on the ground parallel to the given centre line at a distance of
(A) 100 cm
(B) 120 cm
(C) 140 cm
(D) 160 cm

2. The liquid wastes from kitchens, bath rooms and wash basins, is not called
(A) Liquid waste
(B) Sullage
(C) Sewage
(D) None of these

3. The detention time (t) of a settling tank, may be defined as the time required for
(A) A particle to travel along its length
(B) A particle to travel from top surface to bottom sludge zone
(C) The flow of sewage to fill the tank
(D) None of these

4. The following is the physical characteristic of sewage
(A) Turbidity
(B) Color
(C) Odour
(D) All the above

5. The effluent of a septic tank is
(A) Fit for discharge into any open drain
(B) Foul and contains dissolved and suspended solids
(C) As good as that from a complete treatment
(D) None of these

6. The design period of sewage treatment works in normally
(A) 5 - 10 years
(B) 15 - 20 years
(C) 30 - 40 years
(D) 40 - 50 years

7. In Chezy's formula V = C √rs for calculating the velocity of flow in circular sewer of diameter ‘D’ running full, the value of hydraulic mean radius is
(A) D
(B) D/2
(C) D/3
(D) D/4

8. It is customary to design a sewer for D.W.F. on the basis of
(A) Average demand
(B) Twice the average demand
(C) Thrice the average demand
(D) Four times the average demand

9. For sewer mains of 0.5 to 1 m diameter, the ratio of maximum daily sewage flow to the average daily sewage flow is assumed
(A) 1.5
(B) 2.0
(C) 2.5
(D) 3.0

10. Fresh sewage is generally
(A) Alkaline
(B) Acidic
(C) Highly decomposed
(D) A source of objectionable odour

11. The recommended detention period for grit chambers is
(A) 1 minute
(B) 2 minutes
(C) 3 minutes
(D) 5 minutes

12. For detecting the nitrites in the sewage, the matching color may be developed by adding
(A) Potassium permanganate
(B) Sulphuric acid and napthamine
(C) Phenol-di-sulphuric acid potassium hydroxide
(D) None of these

13. If ‘D’ is the diameter of upper circular portion, the overall depth of a standard egg shaped section, is
(A) D
(B) 1.25 D
(C) 1.5 D
(D) 1.75 D

14. The laying of sewers is done with
(A) Magnetic compass
(B) Theodolite
(C) Level
(D) Clinometer

15. A rainfall may be classified as acidic if its pH value is less or equal to
(A) 6
(B) 7
(C) 5
(D) 6.5

Show and hide multiple DIV using JavaScript View All Answers

Blogger Comment