Environmental Engineering Questions (Indiabix)

Environmental Engineering 1.

2.

3.

4.

5.

6.

7.

8.

Suspended solid present in the waste water generated in blast furnace gas cooling and cleaning plant is removed by A.

biological oxygen pond.

B.

radial settling tank (thickener) using coagulant (lime & ferrous sulphate).

C.

lagoons.

D.

filtration.

9.

Persons working in cement plants and limestone quarries are more prone to disease like A.

cancer

B.

asthma

C.

silicosis

D.

flourosis (bone disease)

oxidation followed by settling & filtration.

C.

lime soda process or manganese zeolite process.

D.

chlorination.

In water chemical chloramines ensures

treatment

plant,

A.

disinfection.

B.

taste & odour control.

C.

weed control in reservoirs.

D.

removal of permanent hardness.

A.

fumes

B.

mists

C.

s

D.

aerosols

oke

Operating principle of cyclone separator is based on the action of __________ dust particles. A.

diffusion of

B.

centrifugal force on

C.

gravitational force on

D.

electrostatic force on

of

A.

hydrogen sulphide

B.

mercury

C.

cadmium

D.

asbestos

A.

NOx

B.

Hg

C.

SO2

D.

F

11. During which of the following operating conditions of an automobile, carbon monoxide content in the exhaust gas is maximum ? A.

Idle running

B.

Acceleration

C.

Cruising

D.

Deaccelaration

12. H2S present in gaseous stream can be removed by adsorption on

Exposure to small amount of __________ results in high blood pressure & heart disease in human beings.

A.

silica gel

B.

active carbon

C.

bog iron

D.

limestone powder

13. Inhalation of lead compounds present in automobile exhaust (using leaded petrol) causes

Maximum allowable concentration of CO2 in air for safe working is __________ ppm (parts per million). A.

50

B.

1000

C.

2000

D.

5000

nitrogen

oxides

in

air

is

A.

blood poisoning.

B.

anaemia.

C.

nervous system disorder.

D.

all (a), (b) & (c).

14. Replenishment of dissolved oxygen in water stream polluted with industrial waste occurs by A.

natural aeration of water stream.

A.

0.1

B.

1

B.

photosynthetic action of algae.

C.

5

D.

25

C.

both (a) & (b).

D.

neither (a) nor (b).

Iron & manganese present as pollutant in water can not be removed by A.

use

10. Which of the following is the common pollutant emitted from metallurgical smelters, thermal power plant and cement plants ?

Particulates ( 5000 ppm), man dies because A.

of clotting of blood.

B.

of jamming of respiratory tract.

C.

it forms carboxyhaemoglobin by combining with haemoglobin of blood, thereby making it incapable of absorbing oxygen.

D. 6.

9.

it forms CO2 by combining with oxygen present in the blood.

Workers working in __________ industry are most prone to white lung cancer.

12. Fine grit present in sewage is removed in the __________ during sewage treatment. A.

grit chamber

B.

detritus tank

C.

trickling filter

D.

skimming tank.

13. The lowest layer of atmosphere is known as the

A.

coal mining

A.

stratosphere

B.

limestone mining

B.

troposphere

C.

textile

C.

ionosphere

D.

asbestos

D.

none of these

A standard test for determination of hardness in water is termed as __________ test.

14. As per the world health organisation (WHO) specification, the maximum permissible concentration (i.e., TLV) of particulate matter in air is __________ μg/m3.(μg-microgram)

A.

EDTA

B.

electometric

A.

10

B.

90

C.

total count

C.

800

D.

750

D.

presumptive

15. Which of the following is not a weightless pollutant ?

TLV of lead for public sewer/waste water is about __________ ppm. A.

1

B.

25

C.

150

D.

650

A.

SPM

B.

Thermal pollution

C.

Radioactive rays

D.

Noise pollution

C.

A.

flood

B.

cyclone

C.

decrease in food productivity

D.

all (a), (b) and (c)

17. Which of the following is the most lethal water pollutant ? Phenol and cynide

B.

Chlorine

C.

Alkalis

D.

Suspended solids

18. Presence of carbon monoxide in atmosphere produced by decomposition of chlorophyl and haemoglobin breakdown of some animals, beyond TLV (>50 ppm) A.

acts as a green house gas thereby raising earth's temperature.

B.

causes asphyxia.

C.

causes increase in sea level.

D.

inhances the green house effect.

A.

10

B.

200

C.

1000

D.

2000

20. Which of the following is an adsorbant used for the removal of SO2 from gas/air?

A.

mufflers (silencers).

B.

accoustical absorbent.

C.

lagging of noisy duct.

D.

none of these.

25. The Killer gas which caused Bhopal gas tragedy in 1984 was A.

phosgene

B.

methyl iso-cynate (MIC)

C.

carbon monoxide

D.

sulphur dioxide

26. Aerosols present in atmospheric air may be A.

positively charged.

B.

negatively charged.

C.

neutral.

D.

combination of all (a), (b) & (c).

A.

HF

B.

SO2

C.

H2S

D.

both (b) & (c)

28. Which of the following causes death by asphyxiation, if its presence in atmospheric air exceeds maximum allowable concentration (i.e. > 50 ppm) ?

A.

Bog iron

B.

Limestone powder or alkalised alumina

A.

Benzopyrene

C.

Silica gel

B.

Peroxyacyl nitrate

D.

Active carbon

C.

Carbon monoxide

D.

Sulphur dioxide

of

nitrogen

dioxide

A.

cancer

B.

bronchitis

C.

asphyxiation

D.

corrosion

in

22. Ozone is

29. __________ plant emits large amount of SO2 as an air pollutant. A.

Nitric acid

B.

Sulphuric acid

A.

a primary pollutant.

C.

Chloralkali

B.

a secondary pollutant.

D.

Iron & steel

C.

impervious to ultra-violet rays.

D.

both (b) and (c)

23. The permissible color for domestic water supply is __________ ppm. A.

1

1000

27. Ethanolamine is an absorbant used for the removal of __________ from air/gas.

19. The earth's atmosphere is an envelope of gases present upto a height of about __________ kms.

21. Higher concentration atmospheric air causes

D.

24. High noise levels produced during operation of fans and compressors can be reduced by using

16. Global warming may result in

A.

100

B.

20

30. Noise pollution level in a chemical plant is expressed in A.

roentgen

B.

decibel

C.

hertz

D.

none of these

31. The maximum permissible noise level to which a man working in a chemical plant can be exposed for eight hours per day is about __________ decibels. A.

60

B.

90

C.

105

D.

120

ferrous sulphate

B.

alum

C.

lime

D.

hydrazine

incineration

B.

biological oxidation

C.

composting

D.

none of these

photo-therapy

D.

High voltage electrical equipments.

A.

forestation

B.

rain

C.

green house effect

D.

vegetation

39. Pick out the correct statement.

33. The biological decomposition of organic substances in wastes controlled conditions is called A.

Dermatological equipments.

38. Oceans act as sinks for atmospheric gases including carbon dioxide whose concentration in the atmosphere is increased by the

32. The most commonly used chemical coagulant in water treatment is A.

C.

34. Lung cancer & DNA breakage are the major ill effects of excessive ozone exposure to human beings. Ozone layer depletion in the atmosphere is mainly caused by the presence of

A.

Chemical oxygen demand (COD) is a measure of chemically oxidisable organic matter present in water.

B.

COD is determined by oxidising the organic matter present in water with potassium dichromate in cone, sulphuric acid solution at boiling temperature for specified time.

C.

COD is related to BOD of a given waste in water but the relationship varies for different wastes. Typically COD of potable water may be 1-2 mg/litre.

D.

all (a), (b) and (c).

A.

CO2

B.

SO2

A.

stratosphere

C.

hydrocarbons

B.

troposphere

D.

CFC (chloro fluoro carbon)

C.

ionosphere

D.

none of these

40. The upper layer of atmosphere is called the

35. Smog is not formed due to __________ in the atmosphere.

the

presence

of

41. Which of the following is the most widely used disinfectant in water treatment ?

A.

SO2

B.

NOx

A.

Chlorine

C.

CO2

B.

Irradiation of water by ultraviolet light

D.

any of these

C.

Cation exchanger

D.

Coagulation

36. Pick out the correct statement. A.

Deforestation helps in controlling the green house effect.

B.

Global warming is detrimental for increase in food productivity and may cause flood and cyclone.

C.

Lightening discharges are natural source of production of SO2 & H2S pollutant.

D.

Sulhur dioxide asphyxiation.

causes

death

42. Pick out the wrong statement A.

Low ozone layer thickness in polar regions is due to cold climatic conditions

B.

Amount of unburnt hydrocarbons emitted by two stroke petrol engine is more as compared to that emitted by a four stroke engine.

C.

Carbon monoxide present in the two stroke petrol engine exhaust is much less as compared to that emitted from a four stroke engine.

D.

Mercury as a pollutant can enter the blood stream & the digestive system/ lungs and is responsible for causing minamate disease.

by

37. Which of the following is not a source of ozone emission in the atmosphere ? A.

Refrigerators.

B.

Xerox machines.

43. Phenolic water generated in coke ovens & byproduct plant of a steel plant are disposed off by

50. Which of the following gases is having the widest explosion limit (about 2 to 81% gas in gas-air mixture), rendering it the property of the most explosive gas ?

A.

quenching of hot coke.

B.

discharging in the river stream.

A.

Hydrogen

C.

filtration and recycling for cooling coke oven gas.

B.

Acetylene

C.

Carbon monoxide

D.

none of these.

D.

Ammonia

44. 5-200 μm size particles are called A.

colloids or aerosols

B.

powder

C.

dust

D.

smoke

1.

Pick out the wrong statement pertaining to 'green house' for the plants.

A.

'Green house' (made of glass) allows visible sunlight (i.e., short wavelength solar radiation like ultra-violet rays) to pass through the glass and heat up the soil thereby warming up plants inside it.

B.

The emitted longer wavelength radiation (e.g., infrared) is partly reflected and partly absorbed by the glass of the green house.

C.

'Green house effect' in earth's atmosphere is due to increasing CO2 level in atmosphere. where CO2 acts like the glass of 'green house' thereby warming up the earth's surface.

D.

'Green house' is colder than the outside atmosphere.

45. The progressive warming up of the earth's surface is mainly due to the A.

automobile exhaust.

B.

blanketing effect atmosphere.

C.

de-forestation.

D.

thickening of ozone layer.

of

CO2 in

the

46. The effect of increase in carbon dioxide level of the atmosphere and its profound effect on our climate is called the A.

catalytic conversion

B.

green house effect

C.

global warming

D.

both (b) and (c)

2.

3. 47. Arsenic pollutant is not generated in____industries. A.

tanneries

B.

glass & ceramic

C.

beverages

D.

any of these. 4.

48. The resistance of water to the passage of light through it is a measure of the

In water treatment, alum[Al2(SO4)3] is used for the process of A.

filtration

B.

coagulation

C.

sedimentation

D.

disinfection

Pick out the one which is not a chemical coagulant. A.

Aluminium sulphate

B.

Ferrous sulphate

C.

Hydrated lime

D.

Chloramine

Presence of iron and manganese in water causes A.

reduction in its dissolved oxygen content.

A.

turbidity

B.

discoloration of bathroom fixtures.

B.

color

C.

temporary hardness.

C.

hardness

D.

none of these.

D.

dissolved gases

49. Color test of water is done with an instrument called A.

tintometer

B.

colorimeter

C.

electro-chemical cell

D.

turbidimeter

5.

Septic tanks are used for the __________ of the deposited solids. A.

separation

B.

anaerobic decomposition

C.

aerobic decomposition

D.

none of these

6.

7.

8.

9.

Death may occur, when SO2 concentration atmospheric air exceeds __________ ppm.

in

A.

bronchitis

B.

silicosis

A.

20

B.

100

C.

pneumoconiosis

C.

400

D.

200

D.

none of these

Which of the following acts as a natural source of air pollution ?

14. Solid content in most of the domestic sewage is about __________ percent.

A.

Forest fire

A.

0.001

B.

0.1

B.

Deforestation

C.

5

D.

10

C.

Volcanic eruption

D.

None of these

15. In troposphere (the weather domain), the temperature 't' at height 'h' above the spa level in metres is given by (where, temperature at sea level is 15°C and t is in °C.)

Higher concentration of CO2 in atmosphere A.

allows visible solar radiation (ultraviolet) of short wave-length to pass through.

B.

reflects and absorbs the longer wavelength (infra-red) radiations.

C.

prevents solar heat being radiated out completely, resulting in 'heat trap' i.e., global warming.

D.

all (a), (b) and (c).

Permissible safe limit (TLV) of __________ toxic gas is 100-1000 parts per million (ppm). A.

highly

B.

moderately

C.

extremely

D.

very extremely

A.

t = 15 - 0.0065h

B.

t = 15 + 0.0065h

C.

t = 0.0035h -15

D.

t = 15 - 0.0035h

16. High noise level in a chemical plant can be controlled by the A.

suppression of noise at the source itself.

B.

path control of noise.

C.

protection of operating personnel.

D.

all (a), (b) & (c).

17. Limestone powder is injected during pulverised coal burning in boilers to __________ the flue gases.

10. Radioactive substances present in the polluted water stream can be removed by A.

biological oxygen treatment.

B.

coagulation and filtration.

C.

adsorption in ion exchange materials.

D.

none of these.

11. In the context of the chemical process industries, the term BOD is normally associated with the A.

characterisation of solid wastes.

B.

organic concentration effluents.

C.

characterisation of liquid effluents.

D.

characterisation of boiler feed water.

in

gaseous

12. Noise emitted by a ventilation fan at a distance of 3 metres is about __________ decibels. A.

85

B.

105

C.

125

D.

145

13. Inhalation of silica dust causes a disease called

A.

reduce SO2 content in

B.

catalytically convert SO2 to SO3 in

C.

increase the dew point of

D.

none of these.

18. Main pollutants released from petroleum refineries is A.

CO, SO2 & H2S.

B.

CO2, NO & SO3.

C.

CO2, H2S & NO2.

D.

SO3, NO2 & CO2.

19. Maximum permissible limit of industrial noise as recommended by World Health Organisation (WHO) is __________ decibels. A.

35

B.

75

C.

95

D.

105

20. Which of the following is a green house gas other than CO2 ? A.

Methane

B.

Nitrous oxide

C.

Chlorofluro carbons (CFC)

D.

All (a), (b) and (c)

21. Automobile exhaust is compartments catalytic platinum as catalyst for

passed through two converter employing

A.

conversion of CO into CO2 in the second compartment.

B.

conversion of NOx into N2 and NH3 in the first compartment.

C.

oxidation of unburnt hydrocarbon fuel in the second compartment.

D.

all (a), (b) and (c).

A.

1-2

B.

5-10

C.

150-300

D.

2000-3000

28. Irradiation of water by ultraviolet light of suitable wavelength is commonly used for disinfection of water in A.

food industry.

B.

municipal sewage treatment.

C.

petroleum refinery.

D.

iron & steel plant.

29. When the concentration of SO2 in air is greater than __________ ppm, it gives a pungent smell.

22. Lagooning process is mainly a means of the A.

sludge disposal.

A.

0.01

B.

0.1

B.

reduction of excessive flow in sewers.

C.

1

D.

4

C.

biological treatment of wastes.

D.

none of these.

30. Presence of a certain minimum quantity of flourine is desirable in potable water to prevent

23. Carbon monoxide is a pollutant, which causes A.

respiratory disease (e.g. asthma).

B.

asphyxiation death.

C.

retardation in crop growth.

D.

damage to building materials like marble.

(suffocation)

leading

A.

dental cavities

B.

scale formation

C.

water-borne disease

D.

corrosion

to

31. Pick out the wrong statement. A.

Benzopyrene which causes cancer is present in traces in tobacco, charcoal & petrol driven automobile exhaust.

B.

NO2 is capable of penetrating the troposphere and can absorb both ultraviolet & visible light.

C.

Hydrocarbon pollutants are produced by sweet gum, oak & natural rubber trees.

D.

H2S is not at all produced during combustion of sulphur bearing fuels as all the sulphur is oxidised to SO2.

24. Pollution by particulate matter emission in the atmosphere does not take place during metal A.

grinding

B.

machining

C.

cutting

D.

polishing

25. Direct reaction of unsaturated hydrocarbons with either NO or NO2 produces an eye irritating pollutant compound known as A.

photochemical smog.

B.

peroxy acetyl nitrate (PAN) or methyl nitrile.

C.

benzopyrene.

D.

poly acrylonitrile

26. Pick out the correct statement. A.

Noise from ball mills can be dealt with by fibre glass lined enclosures.

B.

Noise from vibrating chutes can be reduced by lining the metallic chute with rubber.

C.

Noise of conveyor belt system is reduced by using urethane coated cloth conveyor belts and rubber/plastic covered metallic rollers.

D.

all (a), (b) & (c).

27. BOD of raw municipal sewage may be in the range of about __________ mg/litre.

32. Which of the following is not an air pollutant ? A.

Ozone

B.

Carcinogens

C.

Pesticides

D.

Metallic powders

33. Presence of high concentration of ozone and smog in atmospheric air causes the A.

embrittlement & decrease resistance of paper.

B.

cracking of rubber products.

C.

fading of dye on textiles.

D.

damage of electrical insulator on high tension power line.

34. Algae growth in water is controlled by

of

folding

A.

deoxidation

B.

chlorination

C.

bleaching

D.

aeration

35. __________ is removed from water by lime-soda process.

43. TLV of aldrin in public water supply system is about __________ μg/litre. A.

0.5

B.

17

C.

357

D.

1097

A.

Foul smell and taste

B.

Iron and manganese

C.

Temporary hardness

A.

1000 to 2000

D.

Permanent hardness

B.

3000 to 6000

C.

6000 to 9000

D.

10000 to 100000

44. A gas is termed as non-toxic, if its maximum permissible concentration (TLV) ranges from __________ ppm.

36. Most of the bacteria in sewage are A.

parasitic

B.

saprophytic

C.

anerobic

D.

none of these

45. Removal of __________ is accomplished by aeration of water.

37. Which of the following is the most major constituents of air pollutants ?

A.

dissolved gases

B.

suspended solids

C.

dissolved solids

D.

none of these

A.

Oxides of sulphur

B.

Oxides of nitrogen

C.

Carbon monoxide

A.

deforestation.

D.

Hydrogen sulphide

B.

rapid industrialisation.

C.

increased transportation activity.

D.

all (a), (b) and (c).

46. Green house effect is accentuated by

38. Shouting by a man at his full voice corresponds to a voice level of about __________ decibels. A.

25

B.

50

C.

80

D.

120

39. Carbonaceous particles having size less than 1 μm are called A.

grit

B.

aggregates

C.

aerosols

D.

smoke

40. __________ substances present in sewage are removed in grit chamber during sewage treatment. A.

Organic

B.

Fatty

C.

Inorganic

D.

Dissolved

41. The type of bacteria which is active in trickling filter during biological treatment of sewage is the __________ bacteria. A.

anaerobic

B.

saphrophytic

C.

aerobic

D.

parasitic

42. Presence of dissolved impurities of __________ is responsible for the red brownish color of water.

47. Thermal pollution due to excessive temperature in the working place causes A.

reduction in manpower.

working

B.

fatigue.

C.

high breathing rate.

D.

all (a), (b) & (c).

heat

efficiency

48. High concentration of carcinogenic pollutants in atmospheric air causes

&

of

hydrocarbon

A.

cancer

B.

silicosis

C.

respiratory disease (e.g., asthma)

D.

reduced crop yield

49. World environment day is observed every year on the 5th of A.

June

B.

December

C.

July

D.

September

A.

carbonates

B.

bi-carbonates

C.

iron & manganese

A.

pipe vibrations.

D.

arsenic

B.

cavitation.

50. The major reason of hydrodynamic noise (i.e., noise resulting from liquid flow) is

1.

2.

3.

4.

5.

6.

7.

C.

boundary layer separation.

D.

fluctuation in liquid flow.

8.

The term Biological Oxygen Demand (BOD) is used in relation to A.

potable water

B.

cooling water

C.

distilled water

D.

industrial effluents

The destruction of water-borne pathogens is termed as disinfection of water. Which of the following is a water disinfectant ? A.

Chlorine

B.

Alkalis

C.

Benzene hexachloride

D.

Alkyl benzene sulphonate (ABS)

Disinfection of water is done to destroy pathogenic bacteria and thus prevent water-borne diseases. Disinfection of water may be done by the use of A.

ozone and iodine.

B.

chlorine or its compounds.

C.

ultraviolet light for irradiation of water.

D.

all (a), (b) & (c).

Oxidation

B.

Reduction

C.

Dehydration

D.

Fermentation

Infective bacteria in __________ process. A.

sterilisation

B.

aeration

C.

disinfection

D.

none of these

water

is

killed

by

A.

Biological oxygen demand (BOD) is a characteristic and not a constituent of water.

B.

BOD is a measure of the amount of oxygen which will be demanded & used in 5 days by the biological decomposition of the organic matter present in water stream present as food for the living organism.

C.

BOD is expressed in mg/litre (typically, BOD=2.5 mg/litre for potable water).

D.

none of these

The pH value of potable water should be between A.

1 to 1.5

B.

6.5 to 8

C.

13 to 14

D.

4 to 5

10. Maximum permissible limit of mercury in human blood is __________ micrograms/100 c.c. A.

1

B.

7

C.

19

D.

82

11. Which of the following pollutants is absent in the emissions from a fertiliser plant ?

Which of the following processes is involved in the biochemical treatment of sewage effluents ? A.

9.

Pick out the wrong statement.

A.

SO2 & SO3

B.

NO2

C.

NH3

D.

CO

12. Salt content in sea water is about __________ percent. the

A.

0.5

B.

1

C.

3.5

D.

10

13. Noise level inside a jet air liner in normal flight is about __________ decibels.

Fluorosis is caused due to the presence of excessive amount of __________ in drinking water. A.

mercury

B.

lead

C.

fluoride

D.

arsenic

Presence of nitrogen and phosphorous in waste water discharged into lakes and ponds causes A.

foaming

B.

odour nuisances

C.

undesirable plant growth

D.

turbidity

A.

80

B.

100

C.

125

D.

145

14. What is the major constituents of waste/polluted water discharged from textile, pulp & paper, tanning, distillary, dairy and meat packing industries ? A.

Radioactive substances

B.

Natural organic products

C.

Inorganic pollutants

D.

None of these

15. Water filtration rate in a rapid sand filter ranges from __________ kilolitres/m2/hr. A.

0.1 to 1

B.

3 to 6

C.

10 to 15

D.

15 to 20

16. Hazardous/polluting chemical industries should have an 'exclusion zone' with a green belt and general public access prohibited around it, covering a radius of ____ metres. A.

100

B.

1000

C.

400

D.

4000

17. Maximum permissible residual chlorine in treated water should be __________ mg/litre.

B.

appears only on sunny days.

C.

is harmful for crops and trees also besides causing eye irritation & asthma.

D.

all (a), (b) & (c)

23. Reinglemann chart is used for the measurement of the A.

combustibles exhaust.

B.

smoke density from a chimey.

C.

exhaust gas density.

D.

flue gas temperature.

A.

0.001 to 0.01

B.

02 to 0.3

C.

2 to 3

A.

color

D.

5 to 10

B.

bad taste

C.

foul odour

D.

bacteria

Thermosphere

B.

Troposphere

C.

Stratosphere

D.

none of these

in

automobile

24. Disinfection of water is done to remove

18. Which of the following is the most active zone of atmosphere in which weathering events like rain, storm & lightning occur ? A.

present

25. Which of the following fine dust removal equipments is the most efficient ?

19. Which is the most widely used coagulant for the treatment of turbid water ? A.

Alum (aluminium sulphate)

B.

Lime

C.

Ferric chloride

D.

Sodium aluminate

A.

Bag filter

B.

Scrubber

C.

Electrostatic precipitator

D.

Cyclone separator

26. Which of the following industries discharge mercury as a pollutant ?

20. Which of the following is not a natural source of air pollution ? and

Chloro-alkali industry

B.

Tanneries

C.

Beverage plant

D.

Phosphoric acid plant

A.

Volcanic eruptions discharges.

B.

Biological decay of vegetable matter.

A.

5

B.

50

C.

Photochemical matter.

C.

2000

D.

5000

D.

None of these.

oxidation

lightening

A.

of

organic

27. Threshold limit value __________ ppm.

(TLV)

CO

in

air

is

28. Lead exhausted in the atmosphere by automobiles using leaded petrol (i.e. tetraethyl lead for improving octane number) is a lethal air pollutant which causes

21. Threshold limit value (TLV) i.e., the maximum permissible safe limit of phosgene gas which Hitler used to use to kill his enemies in 'gas chamber' is about __________ ppm.

A.

paralysis of muscles & loss of appetite.

B.

nervous depression.

A.