Explore topic-wise MCQs in Environmental Engineering.

This section includes 112 Mcqs, each offering curated multiple-choice questions to sharpen your Environmental Engineering knowledge and support exam preparation. Choose a topic below to get started.

51.

The detention period of a lime soda treatment plant is ____________

A. 1hour
B. 3hours
C. 2-4hours
D. 4-7hours
Answer» D. 4-7hours
52.

By which process, odour producing substances is oxidized?

A. Chlorination
B. Liming
C. Re-carbonation
D. Super-chlorination
Answer» E.
53.

Which of the following is a carbonaceous material?

A. Charcoal
B. Petroleum
C. Hydrogen sulfide
D. Sodium chloride
Answer» B. Petroleum
54.

The Total hardness of soft water as CaCO₃ equivalent is __________

A. 50ppm
B. 100ppm
C. 150ppm
D. 200ppm
Answer» B. 100ppm
55.

The total hardness of water is 100ppm as CaCO₃ equivalent. What is the type of water?

A. Soft
B. Moderately hard
C. Hard
D. Very hard
Answer» C. Hard
56.

Which of the following is a disadvantage of the zeolite process?

A. No sludge is formed
B. The process is almost automatic
C. Suspended impurities get deposited around the zeolite particles
D. Zero hardness can be occurred
Answer» D. Zero hardness can be occurred
57.

Which of the following method is not used for desalination?

A. Distillation
B. Coagulation
C. Reverse osmosis
D. Freezing
Answer» B. Coagulation
58.

The dose of activated carbon in powdered form is controlled by ____________

A. Chromatography
B. Distillation
C. Threshold odor test
D. MPN test
Answer» D. MPN test
59.

The process in which the brackish water is forced across a permeable membrane by mechanical forces is called as _____________

A. Filtration
B. Semi filtration
C. Coagulation
D. Hyper filtration
Answer» E.
60.

The taste produced by a microorganism, can be controlled by ____________

A. Potassium per-manganate
B. Potassium dichromate
C. Sodium chloride
D. Iodine
Answer» B. Potassium dichromate
61.

The temporary hardness in water is due to the presence of __________

A. Sulfates, Chlorides
B. Sulfates, Chlorides, nitrates
C. Carbonates and bicarbonates
D. Sulfates and carbonates
Answer» D. Sulfates and carbonates
62.

What happens when water contains 8-20 ppm of fluoride concentration?

A. Blue baby disease
B. Crippling fluorosis
C. Dental fluorosis
D. Mottling of teeth
Answer» C. Dental fluorosis
63.

The reduction of carbon dioxide by cascade aerators is in the range of __________

A. 10-20%
B. 20-30%
C. 40-50%
D. 50-60%
Answer» E.
64.

Which of the following is not used as a fluoride compound?

A. Sodium fluoride
B. Sodium silico fluoride
C. Hydrofluosilicic acid
D. Sodium fluro carbonate
Answer» E.
65.

The minimum reaction time allowed in the recarbonation basin is ____________

A. 5minutes
B. 10minutes
C. 15minutes
D. 20minutes
Answer» E.
66.

Which of the following is not used for removing the permanent hardness?

A. Lime soda process
B. Zeolite process
C. Demineralization
D. Adding lime
Answer» E.
67.

Dealkalization results in removal of all the ions from the water.

A. True
B. False
C. May be True or False
D. Can't say
Answer» C. May be True or False
68.

The coarse screen is inclined at _____ to facilitate the cleaning or raking.

A. 300
B. 350
C. 450
D. 900
Answer» D. 900
69.

The permanent hardness is also known as __________

A. Pseudo hardness
B. Non carbonate hardness
C. Carbonate hardness
D. Brinell hardness
Answer» C. Carbonate hardness
70.

The elapsed time in gravity filter is 1sec. What is the height of fall in a single descent?

A. 4.4m
B. 4.9m
C. 8.8m
D. 9.8m
Answer» C. 8.8m
71.

For removal of manganese from water ________ mg of oxygen is required.

A. 0.14
B. 0.50
C. 0.29
D. 0.90
Answer» D. 0.90
72.

As far as safer handling is considered, which of the following is used for fluoridation?

A. Sodium fluoride
B. Sodium silico fluoride
C. Hydrofluosilicic acid
D. Sodium fluro carbonate
Answer» D. Sodium fluro carbonate
73.

Which of the following is the pure compound?

A. Sodium fluoride
B. Sodium silico fluoride
C. Hydrofluosilicic acid
D. Sodium fluro carbonate
Answer» B. Sodium silico fluoride
74.

Multistage flash evaporator produces _____ kg of water per kg of prime steam.

A. 5
B. 10
C. 15
D. 20
Answer» E.
75.

The time required for the mixing of lime and soda in lime soda process is _____________

A. 10min
B. 20min
C. 40min
D. 80 min
Answer» D. 80 min
76.

Fluorides in solution form are preferred over powdered form for fluoridation.

A. True
B. False
C. May be True or False
D. Can't say
Answer» C. May be True or False
77.

What is the dose of copper sulfate required for the treatment of water?

A. 0.3-0.6ppm
B. 2-6ppm
C. 4-8ppm
D. 10-20ppm
Answer» B. 2-6ppm
78.

Activated carbon in powder form is applied in the mixing basin.

A. True
B. False
C. May be True or False
D. Can't say
Answer» B. False
79.

The process of reducing the fluoride content from water is called _____

A. Chlorination
B. Fluoridation
C. Defluoridation
D. Flocculation
Answer» D. Flocculation
80.

In which process of water softening, ion exchange phenomenon takes place?

A. Lime soda process
B. Zeolite process
C. Boiling
D. Demineralization process
Answer» C. Boiling
81.

Removal of iron from water takes place at a pH of ______

A. 1.5
B. 3
C. 8.2
D. 9.4
Answer» E.
82.

The color of the natural zeolite is ____________

A. Green
B. Grey
C. Black
D. Blue
Answer» B. Grey
83.

The permanent hardness in water is due to the presence of __________

A. Sulfates, Chlorides
B. Sulfates, chlorides, nitrates
C. Carbonates and bicarbonates
D. Sulfates and carbonates
Answer» C. Carbonates and bicarbonates
84.

Due to the Aswan dam in Egypt, the countries cultivated area has been increased to

A. 4-8 %
B. 3-5%
C. 4-7%
D. 2-5%
Answer» B. 3-5%
85.

There are protozoa present in the water. Its name is Dinobryen. What is the dose of copper sulfate required to kill it?

A. 0.02ppm
B. 0.3ppm
C. 0.5ppm
D. 0.8ppm
Answer» C. 0.5ppm
86.

Which organism is the carrier of sleeping sickness disease?

A. Snail
B. Tsetse Fly
C. Guinea worm
D. Fly
Answer» C. Guinea worm
87.

Which chemical is used for removing the permanent hardness of Calcium chloride?

A. Lime
B. Chlorine
C. Soda
D. Both lime and soda
Answer» C. Soda
88.

In which desalination process, the salt ions are removed from seawater by means of electric current?

A. Distillation
B. Electro-dialysis
C. Reverse osmosis
D. Freezing
Answer» C. Reverse osmosis
89.

The brown tinge in the water is due to the presence of ____________

A. Zinc
B. Copper
C. Iron
D. Manganese
Answer» E.
90.

The maximum salt concentration up to which desalination of brackish water is possible by Electro-dialysis is _____________

A. 1000ppm
B. 2000ppm
C. 3000ppm
D. 5000ppm
Answer» E.
91.

The solar evaporation can yield about ___ kg of fresh water per day per m² of basin surface.

A. 5
B. 10
C. 15
D. 20
Answer» B. 10
92.

Which of the following regarding ozonation is incorrect?

A. Improves the appearance of water
B. Removes traces of color
C. Remove odor
D. Remove phenolic and algae taste
Answer» E.
93.

Fluorex is a special mixture of ____________

A. Di-calcium phosphate and carbon
B. Tri-calcium phosphate and hydroxyapatite
C. Di-calcium phosphate and phosphoric acid
D. Tri-calcium phosphate and carbon
Answer» C. Di-calcium phosphate and phosphoric acid
94.

The zeolite process is unsuitable for water containing iron and manganese.

A. True
B. False
C. May be True or False
D. Can't say
Answer» B. False
95.

Iron and Manganese are generally present in water supplies as ____________

A. Suspension
B. Solution
C. Colloidal particles
D. Either suspension or solution
Answer» E.
96.

By which process dissolved manganese compounds can be converted into insoluble manganese compounds?

A. Aeration
B. Coagulation
C. Sedimentation
D. Flocculation
Answer» B. Coagulation
97.

In which process, excess lime is converted into bicarbonate?

A. Chlorination
B. Liming
C. Re-carbonation
D. Super-chlorination
Answer» D. Super-chlorination
98.

Micro strainers are used to remove color in water.

A. True
B. False
C. May be True or False
D. Can't say
Answer» C. May be True or False
99.

Granular activated carbon has a surface area of ____________

A. 100-200m²/g
B. 500-1400m²/g
C. 400-600m²/g
D. 500-900m²/g
Answer» C. 400-600m²/g
100.

Which material is used in contact filters for the removal of fluorides?

A. Calcium phosphate
B. Copper sulfate
C. Synthetic tri-calcium phosphate
D. Bone charcoal
Answer» D. Bone charcoal