Envi Engg Flashcards
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.
radial settling tank (thickener) using coagulant (lime & ferrous sulphate).
Persons working in cement plants and limestone quarries are more prone to disease like
cancer
asthma
silicosis
flourosis (bone disease)
silicosis
Particulates (< 1μm size) remaining suspended in air indefinitely and transported by wind currents are called
fumes
mists
smoke
aerosols
aerosols
Operating principle of cyclone separator is based on the action of __________ dust particles.
diffusion of
centrifugal force on
gravitational force on
electrostatic force on
centrifugal force on
Exposure to small amount of __________ results in high blood pressure & heart disease in human beings.
cadmium
Maximum allowable concentration of CO2 in air for safe working is __________ ppm (parts per million).
50
1000
2000
5000
5000
Tolerable limit of nitrogen oxides in air is __________ ppm.
0.1
1
5
25
5
Iron & manganese present as pollutant in water can not be removed by
ion exchange process.
oxidation followed by settling & filtration.
lime soda process or manganese zeolite process.
chlorination.
chlorination
In water chemical treatment plant, use of chloramines ensures
disinfection.
taste & odour control.
weed control in reservoirs.
removal of permanent hardness.
disinfection
Which of the following is the common pollutant emitted from metallurgical smelters, thermal power plant and cement plants ?
NOx
Hg
SO2
F
SO2
During which of the following operating conditions of an automobile, carbon monoxide content in the exhaust gas is maximum ?
Idle running
Acceleration
Cruising
Deaccelaration
Idle running
H2S present in gaseous stream can be removed by adsorption on
silica gel
active carbon
bog iron
limestone powder
bog iron
Inhalation of lead compounds present in automobile exhaust (using leaded petrol) causes
blood poisoning.
anaemia.
nervous system disorder.
all (a), (b) & (c).
all (a), (b) & (c).
Replenishment of dissolved oxygen in water stream polluted with industrial waste occurs by
natural aeration of water stream.
photosynthetic action of algae.
both (a) & (b).
neither (a) nor (b).
both (a) & (b).
Aerodynamic noise resulting from turbulent gas flow is the most prevalent source of valve noise in fluid ilow control. It is caused due to
Reynold stresses
shear forces
both (a) & (b)
neither (a) nor (b)
both (a) & (b)
Smoke is produced due to
insufficient supply of combustion air and insufficient time for combustion.
poor quality of fuel and improper mixing of fuel & combustion air.
poor design & overloading of furnace.
all (a), (b) and (c).
all (a), (b) and (c).
Fluorosis (a bone disease) is caused by the presence of high concentration of __________ in atmospheric air.
hydrocarbons
hydrogen flouride
hydrogen sulphides
nitrogen dioxide
hydrogen flouride
Threshold Limit Value (TLV) is the maximum allowable concentration (i.e. safe limit) of pollutants in air. Safe limit for SO2 in air is __________ ppm.
5
500
1000
2000
5
Main pollutants released from iron & steel industry is
CO, CO2 & SO2.
H2S, NO & SO3.
CO2, H2S & NO2.
SO3, NO2 & CO2.
CO, CO2 & SO2.
Exposure to chemicals having carcinogenic properties cause
dermatitis (skin disorder)
cancer
asphyxiation (suffocation)
asthma
cancer
Scale formation in boiler is controlled by
preheating of feed water.
reduction in hardness, silica & alumina in feed water.
keeping the pH value of feed water just below 7.
eliminating H2S in feed water.
reduction in hardness, silica & alumina in feed water.
Noise level heard at a distance of about 100 metres from a jet engine with after burner is about __________ decibels.
120
140
170
200
170
TLV of mercury in potable (drinking) water is about __________ ppm.
0.001
0.1
1
5
0.001
Which is the best and the most effective method for the removal of organic contaminant present in the polluted water in very small quantity (say < 200 mg/litre)?
Lagooning
Activated carbon adsorption
Biological oxidation pond
Chemical coagulation
Activated carbon adsorption
Which is a secondary air pollutant?
Photochemical smog
Sulphur dioxide
Nitrogen dioxide
Dust particles
Photochemical smog
Which of the following is the most detrimental for water used in high pressure boiler ?
Silica
Turbidity
Phenol
Dissolved oxygen
Silica
Turbidity of water is an indication of the presence of
suspended inorganic matter
dissolved solids
floating solids
dissolved gases
suspended inorganic matter
Presence of excess flourine in water causes
dental cavity
tooth decay
fluorosis
respiratory disease
fluorosis
Siderosis is a disease caused by the inhalation of __________ dust.
coal
silica
iron
none of these
iron
Which of the following pollutants is not emitted during volcanic eruptions ?
SO2
H2S
CO
hydrocarbons
hydrocarbons
The main pollutant in waste water discharged from a petroleum refinery is oil (both in free and emulsified form). Free oil is removed by
biological oxygen pond.
aerated lagoons.
trickling filters.
gravity separator having oil skimming devices.
gravity separator having oil skimming devices.
Phenolic water generated in coke ovens & by-product plant attached to an integrated steel plant containing phenol in concentration of less than 100 mg/litre can be removed by
chlorination
treating in biological oxygen pond
chemical coagulation
none of these
treating in biological oxygen pond
Which of the following dust collection equipments is the least efficient (for sub-micronic particles) ?
Dust catcher (gravity type)
Cyclone separator
Bag filter
Hollow wet scrubber
Dust catcher (gravity type)
Bag filter design is predominantly dependent on gas temperature, as it affects the gas density & viscosity and the selection of filtering material. The pressure drop in a bag filter is
inversely proportional to viscosity of gas.
proportional to the viscosity & density of the gas.
proportional to the pressure of the gas.
both (b) and (c).
both (b) and (c).
Dust collection efficiency of a cyclone separator depends upon its
diameter.
inlet gas velocity.
overall height.
all (a), (b) & (c).
all (a), (b) & (c).
Ionisation potential employed in the industrial electrostatic precipitator is of the order of
30 to 70 kV DC
30 to 70 kV AC
230 V AC
230 V DC
30 to 70 kV DC
The widest explosive limit is of __________ , thereby making it the most explosive gas.
acetylene
petrol vapor
hydrogen
carbon monoxide
acetylene
Aerobic biological oxidation ponds used for the purification of polluted water
destroys/removes pathogen from the sewage.
is not very effective for nonbiodegradable substances (e.g. ABS) containing effluents.
destroys/removes pathogen much more effectively if the sewage is chlorinated.
all (a), (b) & (c).
all (a), (b) & (c).
Polluted water having low BOD are most economically treated in
sedimentation tanks
oxidation ponds
sludge digester
clarifier
oxidation ponds
Tri-sodium phosphate is used in boiler water treatment to reduce
turbidity
caustic embrittlement
suspended silica
dissolved oxygen
caustic embrittlement
The commonest form of iron & manganese found in ground water as pollutant is in the form of their
carbonates
bi-carbonates
chlorides
sulphides
bi-carbonates
80% less than 200 mesh size particles are called
smoke
powder
grit
aggregates
powder
Coal washing waste water containing about 3% suspended solids (comprising of clay, slate, stone etc.) is treated for solid particles removal
by chemical coagulation.
in sedimentation tanks equipped with mechanical scrapper.
in vacuum filter.
in clarifiers.
in sedimentation tanks equipped with mechanical scrapper.
Inhalation of lead compounds present in the automobile exhausts (using leaded petrol) causes
blood poisoning.
anaemia.
nervous system disorder.
all (a), (b) and (c).
all (a), (b) and (c).
TLV of ozone (O3) and phosgene (COCl2) in air is __________ ppm.
0.1
25
100
1000
0.1
Most of the atmospheric air pollutants are present in large quantity in
stratosphere
thermosphere
trophosphere
mesosphere
trophosphere
Pick out the wrong statement.
Caustic embrittlement of boiler’s metallic parts is caused by high concentration of caustic soda in boiler feed water.
Cooling and freezing of water kills the bacteria present in it.
With increasing boiler operating pressure of steam, the maximum allowable concentration of silica in feed water goes on decreasing.
Dissolved oxygen content in high pressure boiler feed water should be nil.
Cooling and freezing of water kills the bacteria present in it.
‘Pneumoconiosis’ is a disease caused by the inhalation of __________ dust.
coal
uranium ore
iron ore
lime
coal
The ratio of oxygen available to the oxygen required for stabilisation of sewage is called the
bacterial stability factor.
relative stability.
biological oxygen demand (BOD).
oxygen ion concentration.
relative stability.
Pick out the wrong statement.
The concentric atmosphere layer just above troposphere is called stratosphere, which is rich in ozone.
Mesosphere is characterised by very low atmospheric pressure and low temperature.
Troposhere is a dusty zone containing water vapor and clouds.
The radio waves used in the long distance radio communication are reflected back to earth by stratosphere.
The radio waves used in the long distance radio communication are reflected back to earth by stratosphere.
Most efficient and suitable dust removal equipment for removal of flyash from flue gas in a thermal power plant is the
gravity settling chamber
cyclone separator
electrostatic precipitator
bag filter
electrostatic precipitator
Which of the following is not a secondary air pollutant ?
Ozone
Photochemical smog
Sulphur dioxide
All (a), (b) & (c)
Sulphur dioxide
The concentration of water vapour in troposphere, which depends upon the altitude & temperature varies in the range of zero to __________ percent.
1
4
8
12
4
The main industrial source of emission of hydrogen sulphide air pollutant is
petroleum refineries.
coal based thermal power plants.
pulp and paper plant.
metallurgical roasting & smelting plant.
coal based thermal power plants.
Waste/polluted water discharged from electroplating, blast furnace and coal mining industries contain mainly __________ substances.
radioactive
organic
inorganic
none of these
inorganic
Sound produced by an automobile horn heard at a distance of 1.5 metres corresponds to about __________ decibels.
90
120
150
180
120
Moist atmospheric air at high temperature (e.g., in summer) having high concentration of sulphur dioxide causes
fading of dyes on textiles.
corrosion, tarnishing & soiling of metals.
reduced strength of textiles.
all (a), (b) and (c).
all (a), (b) and (c).
Nitrogen oxides (NOx) is not produced in the __________ industry.
nitric acid making
nitrogenous fertiliser
detergent
any of these
detergent
World’s worst radioactive pollution was caused by nuclear reactor disaster which occured in
Arizona (U.S.A.)
Chernobyl (undivided U.S.S.R.)
Pensylvania (U.S.A.)
Moscow (U.S.S.R.)
Chernobyl (undivided U.S.S.R.)
Dissolved oxygen content in river water is around __________ ppm.
5
100
250
500
5
Oil and grease present in an emulsified state in waste water discharged from industries can be removed by
biological oxidation.
skimming off.
settling out using chemical reagents.
chlorination.
settling out using chemical reagents.
The amount of chemical coagulant added for treatment of polluted water __________ with increase in temperature of the polluted water to be treated.
decreases.
increases.
remains constant.
may increase or decrease ; depends on the chemical characteristics of polluted water.
decreases
Particles having diameter greater than 75 μm (micrometer = 10-6 mm) are called
grit
dust
powder
smoke
grit
Which of the following is the most severe air pollutant ?
hydrocarbons
NOx
SO2
CO
NOx
Presence of bacteria in potable (drinking) water causes
turbidity
disease
bad odour
bad taste & colour
disease
What are the methods of treatment & disposal of radioactive wastes ?
Evaporation & chemical precipitation.
Biological methods & adsorption in ion exchange materials.
Fixing into a solid mass with cement and sinking deep in the sea.
All (a), (b) & (c).
All (a), (b) & (c).
Bacterial aerobic oxidation of polluted water in biological oxidation ponds is done to purify it. Presence of bacteria helps in
coagulation and flocculation of colloids.
oxidation of carbonaceous matter to CO2.
nitrification or oxidation of ammonia derived from breakdown of nitrogeneous organic matter to the nitrite and eventually to the nitrate.
all (a), (b) and (c).
all (a), (b) and (c).
Main pollutant present in automobile exhaust is
CO
CO2
NO
hydrocarbons
CO
Maximum allowable noise exposure limits for a man working for 8 hours a day in a noisy chemical plant is about __________ decibels.
20
60
90
120
90
Industrial workers working in leather tanning & manufacturing units are prone to suffer from
respirtory ailments (e.g. bronchitis).
skin diseases (e.g. dermatities).
silicosis.
blurred vision.
skin diseases (e.g. dermatities).
Pick out the wrong statement.
Biological oxygen demand (B.O.D.) value of a sewerage sample is always lower than its chemical oxygen demand (C.O.D.) value.
Environmental pollution by NOx emission is much higher by four stroke petrol engines as compared to the two stroke engines.
Temperature in stratosphere rises with increasing altitude.
The characteristic of a green house body is that it allows the long wavelength incoming solar radiation to come in but does not allow the short wavelength infra red radiation to escape out of the earth’s atmosphere.
Peroxyacyl nitrate (PAN), a pollutant is found in the
automobile exhaust.
flue gas of coal based power plant.
exhaust of nitric acid plant.
exhaust of sulphuric acid plant.
automobile exhaust.
Foaming and priming in boiler operation can be reduced by reduction in __________ in feed water.
turbidity
color (Hazen)
total solids
all (a), (b) & (c)
all (a), (b) & (c)
Ambient noise level can be reduced by __________ decibels by planting trees (like coconut, neem etc.) near public utility buildings (like hospitals & schools).
1-2
5-10
15-20
25-30
5-10
Pick out the wrong statement.
Catalytic converter is fitted in automobiles to reduce carbon monoxide concentration in exhaust emissions.
Inhalation of pollutant carbon monoxide results in death by asphyxiation.
Sulphur dioxide is the main pollutant emitted from the exhaust of petrol driven automobiles.
Decomposition of plants containing chlorophyll is a natural source of carbon monoxide in atmosphere.
Sulphur dioxide is the main pollutant emitted from the exhaust of petrol driven automobiles.
Which of the following radioactive wastes emits all α, β & γ rays and hence is the most hazardous of all radioactive emitters?
I-131
Sr-90
Au-198
Ra-226
Ra-226
COD of raw municipal sewage may be in the range of about __________ mg/litre.
1-2
5-10
90-120
1500-2500
90-120
Maximum permissible turbidity in potable water is __________ ppm.
1
10
250
1000
10
Presence of __________ hardness is responsible for the temporary hardness in water.
carbonate
calcium
choride
sulphate
calcium
Dose of chlorine for disinfection of water is about __________ mg/litre of water.
0.01
0.1
0.3
1
1
A shallow pond in which the sewage is retained and biologically treated is called
oxidation
Imhoff tank
lagoon
skimming tank
oxidation
Which is the most practical and economical method for removal of suspended solid matter from polluted water ?
Sedimentation
Skimming off
Chlorination
Biological oxidation
Sedimentation
Atmospheric pollution caused by the exhaust gas of supresonic transport air-crafts is mostly in the atmospheric region called
thermosphere
stratosphere
troposphere
mesosphere
stratosphere
Iron & manganese present in the polluted water is removed by
simple filtration.
oxidation followed by settling & filtration.
chemical coagulation.
chlorination only.
oxidation followed by settling & filtration.
Water effluent generated in printing industry is decolourised by
ion exchange technique.
reverse osmosis.
electrolytic decomposition.
adsorption.
electrolytic decomposition.
Thermal pollution of water increases its toxicity and oxidation of oxygen demanding waste besides favouring bacterial growth. A rise in water temperature by 10°C, doubles the toxic effects of __________ present in it.
coal ash
potassium cyanide
ortho-xylene
none of these
potassium cyanide
__________ can not control the noise pollution.
Use of silencers
Green house gases
Vibration damping
Tree plantation
Green house gases
Ozone level is generally found to be depleted in India in the month of
February
July
April
December
December
Noise level during normal conversation among men is about __________ decibles.
10
45
90
115
45
‘Particulate’ air pollutants are finely divided solids and liquids. Which of the following is not a ‘particulate’ ?
Dust & mists
Smoke & fumes
Photochemical smog & soot
None of these
None of these
Foul odour and bad taste of water is removed by treating with
alum
bleaching powder
activated carbon
copper sulphate.
activated carbon
Presence of __________ in water stream are deleterious to aquatic life.
soluble and toxic organics.
suspended solids.
heavy metals and cynides.
all (a), (b) & (c).
all (a), (b) & (c).
Acute danger to human life (i.e. death) exists, if the concentration of CO2 in atmospheric air exceeds __________ percent (by volume).
1
3
7
20
20
Methyl iso-cynate (MIC) gas (TLV <1 ppm), which caused Bhopal gas tragedy in 1984 falls under the category of __________ toxic gas.
moderately
highly
extremely
very extremely
very extremely
Noise level heard inside a bus in busy city traffic or inside a sub-way train corresponds to about __________ decibels.
75
95
120
140
95
Presence of volatile compounds like gasoline, oil, alcohol, ether etc. in municipal sewers may cause
explosion
non biodegradable foam
undesirable plant growth
corrosion
explosion
Noise produced by cooling fans (employed in air cooled heat exchangers or cooling tower) is mainly caused due to the turbulence created by blade passage through air. It can be reduced by use of a slower fan
with greater number of blades.
of increased diameter.
both (a) & (b).
neither (a) nor (b).
both (a) & (b).
Presence of soluble organics in polluted water causes
undesirable plants growth.
depletion of oxygen.
fire hazards.
explosion hazards.
depletion of oxygen.
Which of the following pollutants, if present in atmosphere is detectable by its odour ?
CO
SO2
NO2
CO2
SO2
Exposure to chemicals having carcinogenic properties cause
dermatitis (skin disorder)
cancer
asphyxiation
asthma
cancer
In water treatment plant, zeolite process is used to remove the __________ of water.
acidity
alkalinity
hardness
iron & zinc
hardness
For existence of aquatic life in water, the dissolved oxygen content in it, should not be less than __________ ppm.
10000
5
500
1000
5
Fresh sewage is __________ in nature.
acidic
neutral
alkaline
highly acidic
alkaline
In a sedimentation tank, the detention period for water ranges from __________ hours.
2 to 4
8 to 12
16 to 20
24 to 32
2 to 4
On prolonged exposure to high concentration of carbon monoxide (> 5000 ppm), man dies because
of clotting of blood.
of jamming of respiratory tract.
it forms carboxyhaemoglobin by combining with haemoglobin of blood, thereby making it incapable of absorbing oxygen.
it forms CO2 by combining with oxygen present in the blood.
it forms carboxyhaemoglobin by combining with haemoglobin of blood, thereby making it incapable of absorbing oxygen.
Workers working in __________ industry are most prone to white lung cancer.
coal mining
limestone mining
textile
asbestos
textile
A standard test for determination of hardness in water is termed as __________ test.
EDTA
electometric
total count
presumptive
EDTA
TLV of lead for public sewer/waste water is about __________ ppm.
1
25
150
650
1
Presence of nitrates in water in excess of 50 ppm causes
mathenoglobenemia
gastroentetitis
asphyxiation
tooth decay
mathenoglobenemia
In sewage treatment, the detention period allowed for oxidation ponds ranges from __________ weeks.
1 to 2
4 to 5
9 to 10
15 to 20
4 to 5
Coal mines drainage waste water (acidic in nature) results from the earth’s water percolating through the voids created in coal bed during mining. This polluted water which either drains out naturally to water courses or are removed before starting the mining is
neutralised by alkali treatment.
left as such without any treatment.
diluted with fresh water to reduce its acidity.
none of these.
neutralised by alkali treatment.
Fine grit present in sewage is removed in the __________ during sewage treatment.
grit chamber
detritus tank
trickling filter
skimming tank.
detritus tank
The lowest layer of atmosphere is known as the
stratosphere
troposphere
ionosphere
none of these
troposphere
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)
10
90
800
750
90
Which of the following is not a weightless pollutant ?
SPM
Thermal pollution
Radioactive rays
Noise pollution
SPM
Global warming may result in
flood
cyclone
decrease in food productivity
all (a), (b) and (c)
all (a), (b) and (c)
Which of the following is the most lethal water pollutant ?
Phenol and cynide
Chlorine
Alkalis
Suspended solids
Phenol and cynide
Presence of carbon monoxide in atmosphere produced by decomposition of chlorophyl and haemoglobin breakdown of some animals, beyond TLV (>50 ppm)
acts as a green house gas thereby raising earth’s temperature.
causes asphyxia.
causes increase in sea level.
inhances the green house effect.
causes asphyxia.
The earth’s atmosphere is an envelope of gases present upto a height of about __________ kms.
10
200
1000
2000
200
Which of the following is an adsorbant used for the removal of SO2 from gas/air ?
Bog iron
Limestone powder or alkalised alumina
Silica gel
Active carbon
Limestone powder or alkalised alumina
Higher concentration of nitrogen dioxide in atmospheric air causes
cancer
bronchitis
asphyxiation
corrosion
bronchitis
Ozone is
a primary pollutant.
a secondary pollutant.
impervious to ultra-violet rays.
both (b) and (c)
both (b) and (c)
The permissible color for domestic water supply is __________ ppm.
1
20
100
1000
20
High noise levels produced during operation of fans and compressors can be reduced by using
mufflers (silencers).
accoustical absorbent.
lagging of noisy duct.
none of these.
mufflers (silencers).
The Killer gas which caused Bhopal gas tragedy in 1984 was
phosgene
methyl iso-cynate (MIC)
carbon monoxide
sulphur dioxide
methyl iso-cynate (MIC)
Aerosols present in atmospheric air may be
positively charged.
negatively charged.
neutral.
combination of all (a), (b) & (c).
combination of all (a), (b) & (c).
Ethanolamine is an absorbant used for the removal of __________ from air/gas.
HF
SO2
H2S
both (b) & (c)
both (b) & (c)
Which of the following causes death by asphyxiation, if its presence in atmospheric air exceeds maximum allowable concentration (i.e. > 50 ppm) ?
Benzopyrene
Peroxyacyl nitrate
Carbon monoxide
Sulphur dioxide
Carbon monoxide
__________ plant emits large amount of SO2 as an air pollutant.
Nitric acid
Sulphuric acid
Chloralkali
Iron & steel
Sulphuric acid
Noise pollution level in a chemical plant is expressed in
roentgen
decibel
hertz
none of these
decibel
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.
60
90
105
120
90
The most commonly used chemical coagulant in water treatment is
ferrous sulphate
alum
lime
hydrazine
alum
The biological decomposition of organic substances in wastes controlled conditions is called
incineration
biological oxidation
composting
none of these
composting
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
CO2
SO2
hydrocarbons
CFC (chloro fluoro carbon)
CFC (chloro fluoro carbon)
Smog is not formed due to the presence of __________ in the atmosphere.
SO2
NOx
CO2
any of these
CO2
Pick out the correct statement.
Deforestation helps in controlling the green house effect.
Global warming is detrimental for increase in food productivity and may cause flood and cyclone.
Lightening discharges are natural source of production of SO2 & H2S pollutant.
Sulhur dioxide causes death by asphyxiation.
Global warming is detrimental for increase in food productivity and may cause flood and cyclone.
Which of the following is not a source of ozone emission in the atmosphere ?
Refrigerators.
Xerox machines.
Dermatological photo-therapy equipments.
High voltage electrical equipments.
Refrigerators
Oceans act as sinks for atmospheric gases including carbon dioxide whose concentration in the atmosphere is increased by the
forestation
rain
green house effect
vegetation
green house effect
Pick out the correct statement.
Chemical oxygen demand (COD) is a measure of chemically oxidisable organic matter present in water.
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.
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.
all (a), (b) and (c).
all (a), (b) and (c).
The upper layer of atmosphere is called the
stratosphere
troposphere
ionosphere
none of these
stratosphere
Which of the following is the most widely used disinfectant in water treatment ?
Chlorine
Irradiation of water by ultraviolet light
Cation exchanger
Coagulation
Chlorine
Pick out the wrong statement
Low ozone layer thickness in polar regions is due to cold climatic conditions
Amount of unburnt hydrocarbons emitted by two stroke petrol engine is more as compared to that emitted by a four stroke engine.
Carbon monoxide present in the two stroke petrol engine exhaust is much less as compared to that emitted from a four stroke engine.
Mercury as a pollutant can enter the blood stream & the digestive system/ lungs and is responsible for causing minamate disease.
Carbon monoxide present in the two stroke petrol engine exhaust is much less as compared to that emitted from a four stroke engine.
Phenolic water generated in coke ovens & by-product plant of a steel plant are disposed off by
quenching of hot coke.
discharging in the river stream.
filtration and recycling for cooling coke oven gas.
none of these.
quenching of hot coke.
5-200 μm size particles are called
colloids or aerosols
powder
dust
smoke
colloids or aerosols
The progressive warming up of the earth’s surface is mainly due to the
automobile exhaust.
blanketing effect of CO2 in the atmosphere.
de-forestation.
thickening of ozone layer.
blanketing effect of CO2 in the atmosphere.
The effect of increase in carbon dioxide level of the atmosphere and its profound effect on our climate is called the
catalytic conversion
green house effect
global warming
both (b) and (c)
both (b) and (c)
Arsenic pollutant is not generated in____industries.
tanneries
glass & ceramic
beverages
any of these.
beverages
The resistance of water to the passage of light through it is a measure of the
turbidity
color
hardness
dissolved gases
turbidity
Color test of water is done with an instrument called
tintometer
colorimeter
electro-chemical cell
turbidimeter
tintometer
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 ?
Hydrogen
Acetylene
Carbon monoxide
Ammonia
Acetylene
Pick out the wrong statement pertaining to ‘green house’ for the plants.
‘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.
The emitted longer wavelength radiation (e.g., infrared) is partly reflected and partly absorbed by the glass of the green house.
‘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.
‘Green house’ is colder than the outside atmosphere.
‘Green house’ is colder than the outside atmosphere.
In water treatment, alum[Al2(SO4)3] is used for the process of
filtration
coagulation
sedimentation
disinfection
coagulation
Pick out the one which is not a chemical coagulant.
Aluminium sulphate
Ferrous sulphate
Hydrated lime
Chloramine
Chloramine
Presence of iron and manganese in water causes
reduction in its dissolved oxygen content.
discoloration of bathroom fixtures.
temporary hardness.
none of these.
discoloration of bathroom fixtures.
Septic tanks are used for the __________ of the deposited solids.
separation
anaerobic decomposition
aerobic decomposition
none of these
anaerobic decomposition
Death may occur, when SO2 concentration in atmospheric air exceeds __________ ppm.
20
100
400
200
400
Which of the following acts as a natural source of air pollution ?
Forest fire
Deforestation
Volcanic eruption
None of these
Volcanic eruption
Higher concentration of CO2 in atmosphere
allows visible solar radiation (ultraviolet) of short wave-length to pass through.
reflects and absorbs the longer wavelength (infra-red) radiations.
prevents solar heat being radiated out completely, resulting in ‘heat trap’ i.e., global warming.
all (a), (b) and (c).
all (a), (b) and (c).
Permissible safe limit (TLV) of __________ toxic gas is 100-1000 parts per million (ppm).
highly
moderately
extremely
very extremely
moderately
Radioactive substances present in the polluted water stream can be removed by
biological oxygen treatment.
coagulation and filtration.
adsorption in ion exchange materials.
none of these.
adsorption in ion exchange materials.
In the context of the chemical process industries, the term BOD is normally associated with the
characterisation of solid wastes.
organic concentration in gaseous effluents.
characterisation of liquid effluents.
characterization of boiler feed water.
characterisation of liquid effluents.
Noise emitted by a ventilation fan at a distance of 3 metres is about __________ decibels.
85
105
125
145
105
Inhalation of silica dust causes a disease called
bronchitis
silicosis
pneumoconiosis
none of these
silicosis
Solid content in most of the domestic sewage is about __________ percent.
0.001
0.1
5
10
0.1
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.)
t = 15 - 0.0065h
t = 15 + 0.0065h
t = 0.0035h -15
t = 15 - 0.0035h
t = 15 - 0.0065h
High noise level in a chemical plant can be controlled by the
suppression of noise at the source itself.
path control of noise.
protection of operating personnel.
all (a), (b) & (c).
all (a), (b) & (c).
Limestone powder is injected during pulverised coal burning in boilers to __________ the flue gases.
reduce SO2 content in
catalytically convert SO2 to SO3 in
increase the dew point of
none of these.
reduce SO2 content in
Main pollutants released from petroleum refineries is
CO, SO2 & H2S.
CO2, NO & SO3.
CO2, H2S & NO2.
SO3, NO2 & CO2.
CO, SO2 & H2S.
Maximum permissible limit of industrial noise as recommended by World Health Organisation (WHO) is __________ decibels.
35
75
95
105
75
Which of the following is a green house gas other than CO2 ?
Methane
Nitrous oxide
Chlorofluro carbons (CFC)
All (a), (b) and (c)
All (a), (b) and (c)
Automobile exhaust is passed through two compartments catalytic converter employing platinum as catalyst for
conversion of CO into CO2 in the second compartment.
conversion of NOx into N2 and NH3 in the first compartment.
oxidation of unburnt hydrocarbon fuel in the second compartment.
all (a), (b) and (c).
all (a), (b) and (c).
Lagooning process is mainly a means of the
sludge disposal.
reduction of excessive flow in sewers.
biological treatment of wastes.
none of these.
sludge disposal.
Carbon monoxide is a pollutant, which causes
respiratory disease (e.g. asthma).
asphyxiation (suffocation) leading to death.
retardation in crop growth.
damage to building materials like marble.
asphyxiation (suffocation) leading to death.
Pollution by particulate matter emission in the atmosphere does not take place during metal
grinding
machining
cutting
polishing
polishing
Direct reaction of unsaturated hydrocarbons with either NO or NO2 produces an eye irritating pollutant compound known as
photochemical smog.
peroxy acetyl nitrate (PAN) or methyl nitrile.
benzopyrene.
poly acrylonitrile
peroxy acetyl nitrate (PAN) or methyl nitrile.
Pick out the correct statement.
Noise from ball mills can be dealt with by fibre glass lined enclosures.
Noise from vibrating chutes can be reduced by lining the metallic chute with rubber.
Noise of conveyor belt system is reduced by using urethane coated cloth conveyor belts and rubber/plastic covered metallic rollers.
all (a), (b) & (c).
all (a), (b) & (c).
BOD of raw municipal sewage may be in the range of about __________ mg/litre.
1-2
5-10
150-300
2000-3000
150-300
Irradiation of water by ultraviolet light of suitable wavelength is commonly used for disinfection of water in
food industry.
municipal sewage treatment.
petroleum refinery.
iron & steel plant.
food industry.
When the concentration of SO2 in air is greater than __________ ppm, it gives a pungent smell.
0.01
0.1
1
4
4
Presence of a certain minimum quantity of flourine is desirable in potable water to prevent
dental cavities
scale formation
water-borne disease
corrosion
dental cavities
Pick out the wrong statement.
Benzopyrene which causes cancer is present in traces in tobacco, charcoal & petrol driven automobile exhaust.
NO2 is capable of penetrating the troposphere and can absorb both ultraviolet & visible light.
Hydrocarbon pollutants are produced by sweet gum, oak & natural rubber trees.
H2S is not at all produced during combustion of sulphur bearing fuels as all the sulphur is oxidised to SO2.
H2S is not at all produced during combustion of sulphur bearing fuels as all the sulphur is oxidised to SO2.
Which of the following is not an air pollutant ?
Ozone
Carcinogens
Pesticides
Metallic powders
Ozone
Presence of high concentration of ozone and smog in atmospheric air causes the
embrittlement & decrease of folding resistance of paper.
cracking of rubber products.
fading of dye on textiles.
damage of electrical insulator on high tension power line.
cracking of rubber products.
Algae growth in water is controlled by
deoxidation
chlorination
bleaching
aeration
chlorination
__________ is removed from water by lime-soda process.
Foul smell and taste
Iron and manganese
Temporary hardness
Permanent hardness
Temporary hardness
Most of the bacteria in sewage are
parasitic
saprophytic
anerobic
none of these
saprophytic
Which of the following is the most major constituents of air pollutants ?
Oxides of sulphur
Oxides of nitrogen
Carbon monoxide
Hydrogen sulphide
Oxides of sulphur
Shouting by a man at his full voice corresponds to a voice level of about __________ decibels.
25
50
80
120
80
Carbonaceous particles having size less than 1 μm are called
grit
aggregates
aerosols
smoke
smoke
__________ substances present in sewage are removed in grit chamber during sewage treatment.
Organic
Fatty
Inorganic
Dissolved
Inorganic
The type of bacteria which is active in trickling filter during biological treatment of sewage is the __________ bacteria.
anaerobic
saphrophytic
aerobic
parasitic
aerobic
Presence of dissolved impurities of __________ is responsible for the red brownish color of water.
carbonates
bi-carbonates
iron & manganese
arsenic
iron & manganese
TLV of aldrin in public water supply system is about __________ μg/litre.
0.5
17
357
1097
17
A gas is termed as non-toxic, if its maximum permissible concentration (TLV) ranges from __________ ppm.
1000 to 2000
3000 to 6000
6000 to 9000
10000 to 100000
10000 to 100000
Removal of __________ is accomplished by aeration of water.
dissolved gases
suspended solids
dissolved solids
none of these
dissolved gases
Green house effect is accentuated by
deforestation.
rapid industrialisation.
increased transportation activity.
all (a), (b) and (c).
all (a), (b) and (c).
Thermal pollution due to excessive heat & temperature in the working place causes
reduction in working efficiency of manpower.
fatigue.
high breathing rate.
all (a), (b) & (c).
all (a), (b) & (c).
High concentration of carcinogenic hydrocarbon pollutants in atmospheric air causes
cancer
silicosis
respiratory disease (e.g., asthma)
reduced crop yield
cancer
World environment day is observed every year on the 5th of
June
December
July
September
June
The major reason of hydrodynamic noise (i.e., noise resulting from liquid flow) is
pipe vibrations.
cavitation.
boundary layer separation.
fluctuation in liquid flow.
cavitation
The term Biological Oxygen Demand (BOD) is used in relation to
potable water
cooling water
distilled water
industrial effluents
industrial effluents
The destruction of water-borne pathogens is termed as disinfection of water. Which of the following is a water disinfectant ?
Chlorine
Alkalis
Benzene hexachloride
Alkyl benzene sulphonate (ABS)
Chlorine
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
ozone and iodine.
chlorine or its compounds.
ultraviolet light for irradiation of water.
all (a), (b) & (c).
all (a), (b) & (c).
Which of the following processes is involved in the biochemical treatment of sewage effluents ?
Oxidation
Reduction
Dehydration
Fermentation
Oxidation
Infective bacteria in water is killed by the __________ process.
sterilisation
aeration
disinfection
none of these
sterilisation
Fluorosis is caused due to the presence of excessive amount of __________ in drinking water.
mercury
lead
fluoride
arsenic
fluoride
Presence of nitrogen and phosphorous in waste water discharged into lakes and ponds causes
foaming
odour nuisances
undesirable plant growth
turbidity
undesirable plant growth
Pick out the wrong statement.
Biological oxygen demand (BOD) is a characteristic and not a constituent of water.
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.
BOD is expressed in mg/litre (typically, BOD=2.5 mg/litre for potable water).
none of these
none of these
The pH value of potable water should be between
1 to 1.5
6.5 to 8
13 to 14
4 to 5
6.5 to 8
Maximum permissible limit of mercury in human blood is __________ micrograms/100 c.c.
1
7
19
82
7
Which of the following pollutants is absent in the emissions from a fertiliser plant ?
SO2 & SO3
NO2
NH3
CO
CO
Salt content in sea water is about __________ percent.
0.5
1
3.5
10
3.5
Noise level inside a jet air liner in normal flight is about __________ decibels.
80
100
125
145
100
What is the major constituents of waste/polluted water discharged from textile, pulp & paper, tanning, distillary, dairy and meat packing industries ?
Radioactive substances
Natural organic products
Inorganic pollutants
None of these
Natural organic products
Water filtration rate in a rapid sand filter ranges from __________ kilolitres/m2/hr.
0.1 to 1
3 to 6
10 to 15
15 to 20
3 to 6
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.
100
1000
400
4000
1000
Maximum permissible residual chlorine in treated water should be __________ mg/litre.
0.001 to 0.01
02 to 0.3
2 to 3
5 to 10
02 to 0.3
Which of the following is the most active zone of atmosphere in which weathering events like rain, storm & lightning occur ?
Thermosphere
Troposphere
Stratosphere
none of these
Troposphere
Which is the most widely used coagulant for the treatment of turbid water ?
Alum (aluminium sulphate)
Lime
Ferric chloride
Sodium aluminate
Alum (aluminium sulphate)
Which of the following is not a natural source of air pollution ?
Volcanic eruptions and lightening discharges.
Biological decay of vegetable matter.
Photochemical oxidation of organic matter.
None of these.
None of these.
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.
<1
10-100
100-200
100-1000
<1
Photochemical smog is formed from automobile exhaust
by reaction of hydrocarbon & nitric oxide in presence of sunlight.
appears only on sunny days.
is harmful for crops and trees also besides causing eye irritation & asthma.
all (a), (b) & (c)
all (a), (b) & (c)
Reinglemann chart is used for the measurement of the
combustibles present in automobile exhaust.
smoke density from a chimey.
exhaust gas density.
flue gas temperature.
smoke density from a chimey.
Disinfection of water is done to remove
color
bad taste
foul odour
bacteria
bacteria
Which of the following fine dust removal equipments is the most efficient ?
Bag filter
Scrubber
Electrostatic precipitator
Cyclone separator
Electrostatic precipitator
Which of the following industries discharge mercury as a pollutant ?
Chloro-alkali industry
Tanneries
Beverage plant
Phosphoric acid plant
Chloro-alkali industry
Threshold limit value (TLV) of CO in air is __________ ppm.
5
50
2000
5000
50
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
paralysis of muscles & loss of appetite.
nervous depression.
gastritis & diarrhea.
all (a), (b) and (c).
all (a), (b) and (c).
Oilish impurities present the effluent discharged from the electroplating industry is normally not removed by
chemical coagulation
floatation & skimming
centrifugation
ultrafiltration
chemical coagulation
In large thermal power stations very fine particulates present in flue gas are removed by
wet scrubber
bag filter
electrostatic precipitators
dust catcher
electrostatic precipitators
Threshold limit value (TLV) means maximum permissible/acceptable concentration. TLV of phosgene in air is about __________ ppm (parts per million).
0.002
0.2
1.2
4.8
0.2
The density of the gases (present in air) decreases with increasing altitude to such an extent, that about 70% of the mass of atmospheric air is found in the lower 5 km. of the atmosphere. This lower region of atmosphere is called the
ionosphere
troposphere
stratosphere
none of these
troposphere
Biological oxidation ponds remove organic matters present in the polluted water by
using the activities of bacteria and other micro organisms.
aerobic oxidation.
both (a) & (b).
neither (a) nor (b).
both (a) & (b).
Which of the following is an adsorbant for removal of nitrogen oxides from gas/air ?
Active carbon
Silica gel
Bog iron (iron oxide)
Pulverised limestone
Silica gel
Out of the following, TLV of __________ is the minimum (about 0.02 ppm).
phosgene
bromine
MIC (methyl iso-cynate)
ozone
MIC (methyl iso-cynate)
The average thickness of ozone layer in stratosphere is about __________ dobson unit (DU).
20
230
750
1500
230
Polyvinyl chloride containers are not suitable for storing
foodstuffs
woolen clothes
metallic powder
none of these
foodstuffs
Presence of nitrogen in high concentration in contaminated air reduces partial pressure of oxygen in lungs, thereby causing asphyxia (suffocation) leading to death from oxygen deficiency. Concentration of N2 in contaminated air at which it acts as a natural asphyxant is ≥ __________ percent.
84
88
80
92
84
TLV of ammonia, nitrogen dioxide and phenol vapor in air is __________ ppm.
5
100
1000
2000
5
Corrosion in boilers can be prevented by
deaeration of feed water.
enhancing pH of feed water by adding alkali.
feeding sodium sulphite or hydrazine phosphate to the boilers, which combines with oxygen and prevents corrosion.
all (a), (b) and (c).
all (a), (b) and (c).
Water filtration rate in a slow sand filter ranges from __________ litres/m2/hr.
10 to 20
100 to 200
1500 to 2500
4000 to 5000
100 to 200
Lagoons used for purification of polluted water
are large shallow artificial lakes also known as clarification lakes, maturation ponds or oxidation ponds.
use micro-organisms/bacteria in presence of dissolved oxygen.
gives an excellent final effluent (with 3 to 4 lagoons arranged in series) having suspended solid < 1 mg/litre and BOD = 3.8 mg/litre.
all (a), (b) & (c).
all (a), (b) & (c).
The principal gas evolved from sludge digestion tank is
CO
CO2
CH4
N2
CH4
There are thirteen metals which are treated as pollutants. Which of the following metals is not a pollutant ?
Mercury
Arsenic
Aluminium
Lead
Aluminium
The function of skimming tank in sewage treatment is to remove __________ substances.
dissolved solid
suspended solid
oil & fatty
gritty & inorganic
oil & fatty
The weakest sound that can be heard by a person in a quiet environment is equivalent to __________ decibel.
1
5
10
20
1
Inorganic impurities causing water pollution is
fats
carbohydrates
salts of metals
protein
salts of metals
The main type of sludge gas evolved during sewage treatment in Imhoff tank is
CO2
CH4
CO
H2
CH4
From pollution control point of view, the maximum permissible concentration of sulphur dioxide in atmospheric air is about __________ ppm.
1
5
50
500
5
The pH value of oxidised sewage is about
1.8
6.2
7.3
13.4
7.3
Smog is
nothing but black smoke.
a combination of smoke and fog.
a liquid particle resulting from vapor condensation.
a solid particle e.g. flyash.
a combination of smoke and fog.
_________ is the process of killing organism in water.
Coagulation
Sterilisation
Disinfection
Sedimentation
Disinfection
Reingleman chart No. 2 corresponds to __________ percent black smoke.
10
20
40
80
40
Which of the following is a manmade source of air pollution ?
Automobile exhaust.
Forest fire.
Bacterial action in soil and swamp areas
All (a), (b) and (c).
Automobile exhaust
Which is the most efficient dust removal equipment for removal of sub-micronic dust particles from blast furnace gas ?
Packed scrubber
Gravity settling chamber
Electrostatic precipitator
Hydrocyclone
Electrostatic precipitator
Insufficient washing of sand grains in a rapid sand filter causes
air binding
shrinkage of filtering media
mud balls
expansion of filtering media
mud balls
Which of the following sources is responsible for maximum air pollution ?
Industrial chimney exhaust.
Forest fire.
Automobiles exhaust.
Photochemical oxidation of organic matter.
Automobiles exhaust.
Which of the following is the most efficient for removal of very finely divided suspended solids and colloidal matter from the polluted water stream ?
Sedimentation tank
Circular clarifier
Mechanical flocculation
Chemical coagulation
Chemical coagulation
In sewage treatment, its sedimentation is speeded up by commonly adding
hydrochloric acid.
lime.
copper sulphate.
sodium sulphate.
lime.
Noise level in a quiet private business office is about __________ decibels.
25
50
70
85
50
‘Safe limit’ called Threshold Limit Value (TLV) of carbon monoxide in atmospheric air is < 50 ppm. The main source of carbon monoxide pollutant in air is the
industrial chimney exhaust.
automobiles exhaust.
photochemical reaction in polluted atmosphere.
burning of domestic fuel.
automobiles exhaust.
Inhalation of silica dust by human being causes
asphyxiation
shortness of breath
tuberculosis
both(b) & (c)
both(b) & (c)
Which of the following air pollutants is not toxic to vegetation i.e., doesn’t cause vegetation damage ?
Smog & ozone
Hydrogen fluoride & nitrogen oxides
Sulphur dioxide & spray of weed killers
Carbon monoxide
Carbon monoxide
A masonry structure built below ground level, where biochemical reaction takes place due to anaerobic bacteria is called
cesspool
lagoon
skimming mill
septic tank
septic tank
A considerable part of the harmful ultraviolet radiation of the sum does not reach the earth surface, because of the fact that, there is a layer of __________ high above earth’s atmosphere, which absorbs it.
hydrogen
carbon dioxide
ozone
none of these
ozone
White smoke coming out of the chimney of a furnace indicates the use of
low excess air.
very high excess air.
gaseous fuel in the furnace.
liquid fuel in the furnace.
very high excess air.
TLV of NO2 & NO exposure for the human being is 5 & 25 ppm respectively. Prolonged exposure of human being to NO2 causes
skin disorder
bronchitis
bone disease
cancer
bronchitis
Sulphur dioxide present in the industrial chimney exhaust gases causes
respiratory & lung disease.
reduction in plant’s productivity owing to acid rain.
corrosion of building materials.
all (a), (b) and (c).
all (a), (b) and (c).
A man exposed to excessive noise level in the working environment may suffer from
hearing loss
rupture of ear drum
nervousness & fatigue
all (a), (b) & (c)
all (a), (b) & (c)
Which of the following is a secondary air pollutant ?
Photochemical smog
Sulphur dioxide
Nitrogen dioxide
Dust particles
Photochemical smog
Presence of __________ bacteria in water causes disease like typhoid.
aerobic
pathogenic
anaerobic
non-pathogenic
pathogenic
CFC (chloro fluoro carbon) is very highly reactive in causing depletion of ozone layer in the atmosphere. Each atom of chlorine liberated from CFC is capable of decomposing __________ molecules of ozones.
102
105
109
1015
105
Green house gases blanket/block the infrared radiation from earth’s surface to the atmosphere leading to its progressive warming up. Which of the following gases does not exhibit green house effect ?
CO2
H2
SO3
N2
SO3
A ‘body’ which allows the short wavelength incoming solar radiation to enter in, but does not allow long wave length outgoing infra red radiation to escape out is called the
global warming
green house
atmospheric effect
ionosphere
green house
Fresh domestic sewage is __________ in color.
grey
dark brown
red
black
black
The common pollutant generated in chlor-alkali industry and battery manufacture is
mercury
brine
phosphate
none of these
mercury
During sewage treatment, the sewage is subjected to __________ treatment in Imhoff tank.
filtration
digestion
sedimentation
both (b) and (c)
both (b) and (c)
Black smoke coming out of the chimney of a furnace is an indication of the use of __________ in the furnace.
low amount of excess combustion air
large quantity of excess combustion air
hydrocarbon fuel
pulverised coal as fuel
low amount of excess combustion air
Pick out the wrong statement.
A slight haze at the top of chimney indicates good combustion in the furnace.
A bag filter incurs very small pressure drop and is very efficient for removal of sub-micronic dust particles from flue gases at very high temperature.
Electrostatic precipitator is the most efficient dust collection equipment for removal of sub-micronic dust particles present in flue gas.
none of these.
A bag filter incurs very small pressure drop and is very efficient for removal of sub-micronic dust particles from flue gases at very high temperature.
__________ content of the phosphate rock is the pollutant of primary interest in a phos-phatic fertiliser plant.
Calcium
Fluorine
Phosphorous
Sulphur
Fluorine
Beyond what concentration of H2S in air, acute danger to human life exists ?
50 ppm
100 ppm
300 ppm
700 ppm
700 ppm
Reingleman chart is used for the evaluation of __________ pollution.
air
water
noise
radioactive
air
There are five concentric layers within the atmosphere which is differentiated on the basis of temperature. The atmospheric layer which lies close to the earth’s surface in which human being along with other organisms live is called troposphere. The rate at which air temperature in the troposphere gradually decreases with height is about __________ °C/km.
0.05
1
6.5
15
6.5
Brown spots in fabrics will be caused by washing with water containing large amount of .
iron
zinc
iodine
bromine
iron
Maximum permissible concentration (i.e. TLV) of DDT in public water supply system is __________ micro gram (μ g)/litre.
2
42
332
1050
42
Sooty and sulphurous smog formed due to combustion of fossil fuels particularly in winter, continues throughout the day and night. When the moist atmospheric air’s water vapor condenses on the solid particles of smoke thereby forming smog (smoke + fog), it causes
poor visibility due to sky darkening.
irritation in eyes.
respiratory trouble.
all (a), (b) and (c).
all (a), (b) and (c).
Deaeration of high pressure boiler feed water is done to reduce
foaming from boilers.
its dissolved oxygen content.
its silica content.
caustic embrittlement.
its dissolved oxygen content.
Exposure to SO2 containing chimney gases results in the
reduction in strength of leather & cloth.
acceleration of corrosion rates of metals.
increased drying & hardening time of paints.
all (a), (b)and(c).
all (a), (b)and(c).
The detrimental effect on organism and water quality with temperature rise of aquatic system is the reduction of __________ of water.
dissolved oxygen content
biological oxygen demand
vapor pressure
all (a), (b) and (c)
dissolved oxygen content
Hydrogen ion concentration in distilled water is
10-7
7 x 10-7
107
7 x 107
10-7
Out of the following, TLV of __________ is maximum (about 500 ppm).
carbon dioxide
toluene
carbon disulphide
acetaldehyde
carbon dioxide
Which of the following plants does not emit appreciable amount of SO2 in atmosphere ?
Thermal power plant
Petroleum refinery
Nitric acid plant
Sulphuric acid plant
Nitric acid plant
The maximum CO2 is emitted into the atmosphere by
combustion
urea
biomass burning
trees
combustion
Which of the following is not a practical method of low level radioactive waste disposal ?
Dilution with inert material.
Discharging to atmosphere through tall stacks after dilution.
Disposing off in rivers & oceans.
Filling in steel crates and shooting it off out of earth’s gravity.
Filling in steel crates and shooting it off out of earth’s gravity.
Major sources of noise in furnace operation arises from air inspirators, combustion, side wall vibrations and fluctuation in the process heat load. A 50% increase in fuel firing rate may increase the furnace noise level by about __________ decibels.
3
30
70
100
3
Removal of __________ results from the disinfection of water.
turbidity
odour
hardness
bacteria
bacteria
Very small amount of air pollutants are present in stratosphere also; though most of the atmospheric pollutants are present in the troposphere. Which of the following atmospheric pollutants does not cause the ozone layer depletion in atmosphere at tremendous rate ?
CO
SO2
NOx
CFC (chloro fluoro carbons)
CO
Carcinogenic air pollutants cause
bone decay
cancer
asphyxiation (suffocation)
anemia
cancer
Inhalation of silica dust by human being during hand drilling in mica mining, lead & zinc mining, silica refractory manufacture and in foundaries causes
asphyxiation (suffocation).
shortness of breath.
tuberculosis.
all (a), (b) and (c).
all (a), (b) and (c).
Soluble silica present in boiler feed water can be removed by
coagulation
filtration
anion exchanger
preheating it
anion exchanger
Presence of non-biodegradable substances, like alkyl benzene sulphonate (ABS) from the detergents in polluted water stream causes
fire hazards.
explosion hazards.
persistent foam.
depletion of dissolved oxygen.
persistent foam.
Pick out the wrong statement.
The concentric layer in atmosphere which contains about 70% of the total mass of atmosphere and characterised by a steady decrease in temperature is called stratosphere.
Stratosphere is rich in ozone and is located just above the troposphere.
Troposphere is a turbulent dusty zone containing much of water vapor and clouds.
The earth’s atmosphere is an envelope of gases extending upto a height of about 200 kms.
The concentric layer in atmosphere which contains about 70% of the total mass of atmosphere and characterised by a steady decrease in temperature is called stratosphere.
Radioactive solid nuclear wastes are disposed off by
high temperature incineration.
pathological incineration.
pyrolysis.
underground burial in concrete containers.
underground burial in concrete containers.
Growth of __________ is promoted by the presence of manganese in water.
files
algae
micro-organisms
mosquitoes
micro-organisms
Average human body contains about __________ percent water by weight.
20
40
70
85
70
Noise level audible to audience sitting in the 5th row from the stage during a large orchestra show corresponds to about __________ decibels.
105
135
160
185
135
If carbon monoxide content in atmospheric air exceeds __________ ppm, death is bound to occur.
50
500
1000
3000 (i.e. 0.3%)
3000 (i.e. 0.3%)
