95.

96.

97.

98.

99.

100.

073/23

Which of the following is not a biological treatment method for sewage ?
A) Trickling filters B) Activated sludge process
C) Grit chamber D) Aerated lagoons

Which of the following pipe appurtenance is used to prevent flow of water in backward
direction ?
A) Sluice valve B) Relief valve C) Reflux valve D) Scour valve

Sewerage system in which both sewage and storm water taken into a single sewer
is known as

A) Separate system B) Combined system
C) Partially separate system D) Partially combined system

Match the Column | and Column II:

Column -1 Column - Il

a. Dead end system i Distribution reservoirs at centers of
different zones

b. Grid iron system ii. Mains provided around the periphery of
distribution area

c. Ring system iii. No free circulation of water

d. Radial system iv. Longer length pipe required

A) a-iii, b - ii, c—i, d—iv B) a-iv, b-iii, c—ii, d-iv

C) a-iii, b-iv, c-ii, d-i D) a-iv, b-ii, c-iii, d-i

Which of the following statement is not true about septic tank ?
|. Sedimentation tank with provision of storage and digestion of sludge.
Il. Digestion of sludge is done by aerobic bacteria inside the tank.
Ill. Periodic cleaning of septic tank is required as accumulation of sludge can
decrease capacity of tank.
IV. Effluent from septic tank can be taken to soak pit for disposal.

‎B) ll only C) Ill only D) IV only‏ ۷ ھ
‎Which of the following is not a method of aeration adopted for treatment of raw water ?‏
‎A) Air diffusion B) Cascades‏
‎C) Adding air entraining agents D) Spray nozzles‏

‎-15-