Environmental Pollution
Q. What are the main sources of air
pollution?
Ans : (i) Natural sources (ii) Manmade sources
Q. What are the major air pollutants?
Ans: CO, NO2, SO2,
VOCs,.suspended particular matter etc.
Q. What are the greenhouse gases?
Ans: These include CH4,
water vapour, carbon dioxide, CFCS etc.
Q. What are the main causes of water
pollution?
Ans : Wastes from industries, Excessive
heat, Agricultural activities, Domestic wastes
Q. Write two major effects of water
pollution?
Ans : (i) Nitrates (more than 90 ppm)
from the industrial wastes cause "Blue baby syndrome" disease.
(ii) Hg, As, Pb cause damage to the
central nervous system
Q. Write one of the control measures of
soil pollution.
Ans : (i) Proper action should be taken
before the disposal of domestic wastes, chemical wastes into the soil.
Q. How is noise pollution measured?
Ans: The intensity of sound is measured
in sound pressure levels (SPL) and common unit of measurement is decibel, dB
Q. What are the major domestic sources
of noise pollution?
Ans : Domestic (movement of utensils,
home appliances pressure cooker, television, air cooler, air conditioners etc.
Q. State True of False :
(a) High temperature causes the quality of
the digestive juice.
Ans : True.
(b) Salmon and Trout fish can lay eggs in
high temperature.
Ans : False.
Q. Who is most responsible for environmental pollution?
Ans : Man..
Q. What happened in
the USA in 1962-65?
Ans : The USA experienced in severely dry
climate-and bitter cold in 1962-65.
Q. What happened in UK during 1961-62?
Ans : The UK experienced drought and
erratic climate 1961-62.
Q. What did Russia
suffer in 1971?
Ans : Russia suffered extremely low
temperature in 1971.
Q. What natural
calamity happened in India in 1978?
Ans : India was badly
affected by flood in 1978.
Q. When drought badly
affected India.
Ans : In 1980,
drought badly affected India.
Q. When did the
industrial revolution take place?
Ans : Towards the end
of 18th century, the industrial revolution took place.
Q. What is abnormal
climate?
Ans: When pollution
occurs in the environment abnormal changes occur in the climates also. This is
called abnormal climate.
Q. Why do floods occur in Assam every
year?
Ans : Deforestation and the unplanned
construction of embankments are the main causes of floods in Assam.
Q. Describe the
atmosphere of Guwahati city.
Ans : The atmosphere
of Guwahati is also very much polluted by the smoke, ashes, garbages and
population. The motor vehicles and population are mostly responsible for
environmental pollution in Guwahati.
Q. What is the full
form of SMP?
Ans: the full form of
SMP is Suspended Particulate Matter.
Q. When and where did
the industrial revolution take place?
Ans: The industrial revolution took
place in 18thcentury in Europe.
Q. What is the full form of MIC?
Ans : The full form of MIC is Methyl
Isocyanate.
Q. Write the name of
the most populous city of India.
Ans : Kolkata is the
most populous city of India.
Q. How do the jet
planes also pollute the atmosphere?
Ans : The jet planes
release aerosol in the upper layer of the atmosphere and pollute the
atmosphere.
Q. Which agent is the
most responsible for air pollution?
Ans: Motor vehicle is the most
responsible for air pollution.
Q. When did the government
of India enforce air pollution act?
Ans : The government of India enforced
the Air Pollution Act in 1981.
Q. What are the
causes of lung cancer and bronchitis?
Ans : The SPM and sulphur-di-oxide are the causes of lung cancer and bronchitis.
Ans : The SPM and sulphur-di-oxide are the causes of lung cancer and bronchitis.
Q. Which elements
damages our blood circulation system, liver and kidneys?
Ans: Air-born lead damages our blood
circulation system, liver and kidneys.
Q. What is personal
air pollution?
Ans: When air pollution affects the
health of an individual person it is called personal air pollution.
Q. Which elements
create acids rain?
Ans : Sulphur oxides and nitrogen
oxides create the acid rain.
Q. Write the name of
the famous forest of Germany destroyed by acid rain.
Ans : Black forest.
Q. What is the most
sophisticated technology to get rid of impurities in water?
Ans : The effluent treatment plant is
the sophisticate technology to get rid of impurities in water.
Q. What is the full form of ETP?
Ans : The full form
ETP is Effluent Treatment Plant.
Q. What is the full
form of DDT.
Ans: The full form of
DDT is Dichloro-diphenyl-trichloro-ethane.
Q. Name the worst
elements that disturb the ecosystem.
Ans: The destruction of forests and
increasing population are the worst elements that disturb the ecosystem.
Q. In which century
did the industrial revolution take place?
Ans : Towards the end of 18th century
the industrial revolution took place.
Q. What is soil?
Ans : Soil is the upper weathered layer
of the upper crust of the earth.
Q. What are the main
agents that cause soil erosion?
Ans : Wind and water are the main
agents that cause soil erosion.
Q. What are microbes?
Ans: The minute organisms which enrich
the soil and make it fertile are called microbes.
Q. What is the cause
of alkalinity of land?
Ans: Alkalinity is caused by imbalance
use of fertilisers.
Q. What are the
precursors of green revolution?
Ans: Fertilisers and pesticides are
called the precursors of green revolution.
Q. What is the amount
of garbage produced by a man in a day in India.
Ans: Each person produces about 300-600
gm garbage in a day In India.
Q. In what type of
land does erosion of soil by wind occur?
Ans: The removal of top soil by violent
wind is a common phenomenon to those areas which are dry and devoid of any form
of vegetation.
Q. How is salinity of
land caused?
Ans: Salinity of land is caused due to
frequent irrigation by river water which in its course tends to colfefct salt
of various forms from the mountain surface.
Q. What is meant by
soil pollution?
Ans : Decrease in the quality of soil
either due to anthropogenic sources or natural sources or by both is called
soil pollution or soil degradation.
Q. What is frequency?
Ans : The number of
vibrations produced per second is called frequency.
Q. What is the safety
range of sound?
Ans: Generally the safety range lies
from 30 to 60 decibels.
Q. What kind of sound
can our ear detect?
Ans: Our ear can detect the sound from
0 to 180 decibels.
Q. How is the sound
created?
Ans : The sound is created by a
vibrating body.
Q. What is the
average sound of a siren?
Ans : The average sound of a siren is
150 to 160 decibels.
Q. In India, how many
people are born deaf, for noise pollution?
Ans: Almost 10 million people are bom
deaf, in India in a year, for noise pollution.
Q. What is the
average noise level of Delhi?
Ans: The average noise level of Delhi
is above 90 decibel.
Q. What is decibel
and its use?
Ans
: The unit of the intensity of sound is called decibel. The degree of
noise is determined by this unit.
Q. Generally what
type of sounds pollute the environment?
Ans : The sound from industries,
factories, heavy diesel vehicles, motor bikes, .whistles of train and vehicles,
diwali crackers etc. pollute the environment.
Q. How many people
lose their hearing power every year in Sweden?
Ans: In Sweden every year almost 16,000
people lose their hearing power due to noise pollution.
Q. What is Radiation?
Ans : All the electromagnetic waves are
called radiation.
Q. Which
electromagnetic wave is very harmful for us?
Ans : Gamma electromagnetic wave is very
harmful for us.
Q. Which
electromagnetic wave has no charge?
Ans : Gamma electromagnetic wave has no
charge.
Q. What is an
electron?
Ans : An electron is a very small
particle with negative charge and it is found in all atoms.
Q. Why Uranium,
Thorium and Plutonium are used to produce nuclear energy and weapon.
Ans: Uranium, Thorium and Plutonium are
heavy elements and they are radioactive in nature.
Q. What is called
'natural selection'?
Aas : The abnormalities are eliminated
in plants by the evolutionary process called, 'natural selection'.
Q. What is 'nuclear
winter'?
Ans : Nuclear explosion may cause a
peculiar situation. The scientists call this peculiar situation, 'nuclear
winter'.
Q. What is
radioactivity?
Ans: Radioactivity is the spontaneous
emission of powerful radiations fiom some substances without any energy being
supplied from outside.
Q. 'The Discovery of
nuclear weapon is very dangerous for mankind’. Explain.
Ans : The nuclear weapons destroy our
present and the radioactive radiations of nuclear weapons destroy our future.
That is why nuclear weapon is very dangerous for us.
Q. What are the air
polluting substances released in India?
Ans : Sulphur-dioxide,
carbon-dioxide, hydrocarbons, hydrogen sulphide, SMP and lead particles are the
polluting substances released in India.
Q. What is 'smog'?
Ans : Nitrogen oxides and
hydrocarbons form a layer at high temperature in our atmosphere, it is called
smog. It is a grey or yellowish brown opaque substance deposited in air.
**********************************
Short notes:
(a)Tropical region: Equator
divides our earth into northern and southern hemispheres. The nearby areas of
the equator on both sides are under the Tropical region. For the climatic
changes the| tropical regions are badly affected. The countries of the tropical
region now face many problems. But the floods and droughts are the major
problems for them.
(b) Polar regions:
Our earth has two poles - north pole and south pole. These are called Polar
Regions. The Polar Regions are called water reservoirs, because the Polar
Regions are always covered with thick ice. At present the scientists are
concerned about the global warming. If the global warming increases, the ice of
the Polar Regions will melt, and floods will occur almost all over the world.
(c) The Himalayas : Himalayas are the highest mountain
range of the world. It is also water, reservoir, because many parts of the
Himalayas are covered with thick ice. Many big rivers of India come out from
the Himalayas. So if the global warming increases, the Himalayas will supply
more water to the river, and floods will occur in many places.
(d) Aerosol: Aerosol
is fine solid or liquid particles in the atmosphere which exert a lot of
influence on the other gases including sulphur-dioxide. It exists in air in the
form of smoke, fog and vapour. It is very harmful for our atmosphere.
(e) Fossil
fuel: The remains of organisms embedded in the surface of the earth,
contain high carbon and hydrogen. Those elements are used by man as fuel. This
kind of fuel is called fossil fuel.
(f)
Minamata disease : The water polluted with mercury may causes
many a disease. One such disease occurred first in the Bay of Minamata in
Japan. So this disease is called Minamata disease.
(g) Mercury : Mercury
is a poisonous substance. Use of mercury has been increasing rapidly as it is
required especially in paper mills and electrical industries. Some other industries
also use mercury. Now the production rate of Mercury in me world is about 9,000
tons per year. The water polluted with mercury may cause many diseases in
aquatic and other animals.
(h) Household-waste : Cowdung,
carcasses of cattle, dogs, cats, goats and other animals, excreta of various
animals, lumps of straw and hay, various types of vegetable wastes, litters etc.
are called house-hold wastes. These house-hold wastes also pollute the water.
Q. Describe the reasons of changes in
weather and climate?
Ans : There are many natural and
man-made reasons of changes in weather and climate. But men are more responsible
than the nature. The burning of fossil fuels, the rapid population growth,
destruction of forest etc. are the main factors of environment pollution. These
are the main reasons of changes in weather and climate.
Q.
Describe what happened to the climate of the world during the second
half of the hat century.
Am: During the second half of the last
century, we found many changes in climate. In 1962-65, the USA had the experience
of a severely dry climate and bitter cold, in 250 years. The UK had the experience
of the coldest climate in 1961-62. Europe also suffered drought in 1976. Russia
suffered the extremely low temperature in 1971.
Q. How do the changes
in climate affect the people in the developing counties?
Ans: The developing countries are
generally located in me monsoon regions. For the climatic changes me monsoon
shows the erratic behaviour in these regions. As a result, heavy floods or
drought occur. In the developing countries most people depend on agriculture.
If the floods or drought occur every year, that means heavy damaged to the
crops. The irregularity of monsoon also affects the crops and the life of the
people. In this way the climatic changes affect the people in the developing
countries.
Q. What did happen to
the Brahmaputra and Barak valleys in the second half of the last century?
Ans : Since the second half of the last
century, there have been heavy floods in the Braghmaputra and Barak valleys of
Assam. Severe drought conditions also occurred. So the floods and drought are
perennial problems of Assam. For the climatic changes, the south-west monsoons
are very irregular in these regions and there is scanty of rain.
Q. Discuss the
abnormal climatic conditions of the world.
Ans: For the natural and mad-made
factors some abnormal behaviour has been observed in nature, hi 1962-65, the
USA had the experience of a severely dry climate and bitter cold. The UK had
experienced the coldest climate in I961-62. Drought and erratic climate were
the main features of Europe in 1976. Russia had experienced the extremely low
temperature in 1971. Destruction of forests and tropical rah, forest are
the causes of abnormal climate.
Q. Discuss the main
causes of climatic changes.
Ans : For climatic
changes both the nature and man are responsible. But man are more responsible
than the nature. The rapid growth of population, deforestation, excessive use
of natural resources, burning of fossil fuels, increasing industries are me man
causes of climatic changes
Q. Why do floods
occurs in Assam so often.
Ans:In Assam the
rainfall is decreasing and even then the floods occur every year. Deforestation
and unplanned construction of embankments are the main causes behind the rise
of river-beds and consequently floods occur frequently.
Q. How do the developing countries hamper
the ecosystem? Discuss.
Ans: The rate of population growth is
higher in developing countries than the developed countries. People pollute me
air and destroy the forests for more cultivable lands. The rapid increase of
population also hampers the progress of the developing countries and leads to
poverty and undue interference on the activities of the ecosystem. In this way
the developing countries hamper the ecosystem.
Q. Discuss, how the climatic changes,
hamper the progress of the developing counties?
Ans: Generally the developing countries
are located in the monsoon regions. The monsoons greatly influence the lives of
the people. Most of the people depend on agriculture and agriculture depends on
monsoon.
But for the climatic changes, the
monsoon shows an erratic behaviour in those regions. As a result every year
floods or droughts take place in those regions and hamper the crops. The
monsoons come sometimes early, sometime late and sometimes they show uncertain
behaviour. In this way the climatic changes hamper the progress of
the developing countries.
Q. ‘Urban areas are most responsible
for environmental pollution'. Discuss
Ans : The industries, factories etc.
are mostly established in city or towns. The industries, factories etc. burn
the fossil fuels and release a large amount of smokes and ashes to our environment.
There are plenty of motor vehicles which burn the petrol, diesel etc and
produce a plenty of smoke and ashes and pollute the atmosphere. The urban areas
generally provide more opportunities for earning livelihood. So the people come
to the towns or cities. The people also pollute the air. In some cities or
towns many forests are also destroyed for their own projects. For these reasons
urban areas are responsible of environmental pollution.
Q. What is 'Green House Effect'?
Discuss.
Ans: Industries, factories and motor
vehicles burn the fossil fuels and pollute our atmosphere. The polluted air
contains carbon-di-oxide, carbon monoxide, methane, lead, aerosol etc. These
elements allow the sun rays to fall on earth and on the other hand traps the
outgoing radiation from the earth. In this way these elements help to increase
global warming. This phenomenon is called 'Green House Effect.'
Q. What is air
pollution? What are its categories?
Ans :
The presence of pollutants in air which is the cause of injury and damage to
human beings, animals, plants and other objects is called air pollution. Air
pollution is of three categories. These are - personal, occupational and
community air pollution.
Q. 'Nature also
pollutes air' - Explain. Ans: Air pollution is also caused by
nature itself. It may be due to respiration from man and animals, dusts,
bacteria, fungi, pollens, spores, volcanic gases etc. So it is said, 'nature
also pollutes air'.
Q. Describe the extent of air pollution
in some major cities of the world.
Ans : The air of some
industrial cities are always covered with smog. An aerial view of the cities
like London, Tokyo, New York etc. shows that these cities are covered with
thick smog. Excessive burns of petrol, diesel, coal etc. produce the harmful
gases like carbon-di-oxide, nitrogen oxide and sulphur-dioxide and they pollute
the air. The rapid urbanisation, deforestation, land erosion are also the
causes of air pollution.
Q. Can air pollution be rooted out
entirely? How can it be controlled?
Ans : No, the air
pollution cannot be rooted out entirely. The air pollution can be controlled as
follows :
· We
should reduce burning fossil fuels and think for alternative fuels.
· We
should change our old technology and industrial equipments.
· The
government should strictly enforce the law of Pollution.
· We
should use purified fuel in our motor vehicles.
· Plantation
of trees is also a good method to control air Pollution.
Q. Describe the legal and organisational
aspects of controlling air pollution.
Ans : The government of India .has
enacted a law in 1981 to control and prevent the air pollution. This act is
implemented by central pollution control board and state pollution control
boards. Thus government organisations are now handling the law of pollution to
control air pollution.
Q. What is the best
way to minimise air pollution?
Ans : The best way to
minimise air pollution is to replace the old technology and the equipments of
industries, factories; motor vehicles etc. and think for new anti-pollution
devices.
Q. Discuss the major
causes of air pollution.
Ans : The major
causes of air pollution are :
a.
We burn excessive fossil fuels in
industries, factories and motor vehicles and produce a huge amount of harmful
gases and smoke and pollute the air.
b.
The rapid growth of population pollute the
air.
c.
The rapid urbanisation, deforestation, land
erosion etc. also pollute the air.
Q. What are the sources of water
pollution?
Ans : There are many sources which are
responsible for water pollution. Among them eroded soils, decomposed body of
plants and animals, fallen leaves, organic materials, chemical fertilizers,
industrial wastes, municipal and house-hold wastes are the main sources of
water pollution.
Q. How does mercury
pollute water?
Ans : Some industries use mercury
compounds. Mercury has been increasing through paper mills and electronical
industries. When this poisonous compound mixes with-water, it causes many
diseases in our body. In this way the mercury pollutes water.
Q. How do ships
carried crude oil pollute the sea water?
Ans : When crude oil is carried by
ships across seas and oceans, some crude oil spills to the seas owing to
leakage and other reasons. This spilt crude oil spreads over wide area forming
a scum. Crude oil neither dissolves in water nor evaporates. It remains in
water for a very time and pollute die sea water which is very harmful for
marine lives.
Q. How did mercuric
compound cause Minamata disease?
Ans : The industries dumped mercury
compound on the shore of the Minamata Bay of Japan. This poisonous compound
pollutes the water. Fish were affected by the polluted water and the
inhabitants of Minamata Bay consumed those fishes as food and tftis disease
occurred there. In this way the mercuric compound caused Minamata disease.
Q. Describe how seas
and oceans are polluted?
Ans : The polluted
water of towns, cities and agricultural fields flows through the rivers and
their tributaries to seas and pollute the sea water.
 |
The crude oil spreads in seas and
oceans through the leakage of huge oil tankers carrying oil. This crude oil is
neither dissolved in water nor evaporated. It remains in water for a long time
and pollutes the water and affects the marine lives.
Q. Explain how the water
drawn from wells may be harmful?
Ans : The rivers and their tributaries
carry the poisonous substances to the sea. These substances may go down the
earth's crust and pollute the underground water, which we use for our drinking.
So the water drawn from wells may also be harmful for our health.
Q. How are the
aquatic lives affected by pollution?
Ans : The nutrients
in the lakes, river, seas etc. help algae and weeds to grow under water
luxuriantly. They consume large amount of oxygen and exhaust the stock of
oxygen and create a dearth of oxygen in sea water which, greatly hamper the
aquatic lives. In this way the aquatic lives are affected by pollution.
Q. What is
environment?
Ans: Environment means surrounding; we
are surrounded by abiotic and biotic factors of environment. The various types
of radiation, air, water, rocks etc., form the abiotic environment. Living
organisms that interact among themselves form the biotic environment.
Q. What does
environment sciences provide us with?
Ans: Environment science
provides us with an approach towards Understanding the environment of our
planet. It also tells us about the impact of life on it and vice-versa. It also
makes us to enquire for the solutions to environmental problems that confront
mankind now.
Q. What special
position does the earth enjoy in the solar system?
Ans : The special position of the earth
in the solar system is that it is the only planet that supports life. The
environment of the earth is conducive for the existence, growth and development
of livingbeings.
Q. What is solar
system? How many planets are there in it? While is the planet that supports
life?
Ans: The sun and its family of nine
planets along with their satellites is the solar system. There are nine planets
in it. The earth is the only planet that supports life.
Q. How does
environment affect life on earth?
Ans: Environment affects the size,
shape and colour of plants animals and the ways in which they grow and live.
Environment is responsible for survival of any particular organism. We get
food, clothing and other things necessary for our survival from environment.
Q. Mention some of
the uses of water?
Ans : Water is essential for sustaining
life. Water is also used for bathing, washing cleaning, irrigating crop lands,
generating electric powers, running factories and for many other service.
Q. Write briefly
about Hydrosphere?
Ans : Hydrosphere includes all water
bodies on earth. The oceans, seas, rivers, ponds etc. are all parts of it.
Oceans and seas cover 71 % of the hydrosphere. Only 0.04% is frets water usable
by man and other animals. Water is not as scarce as petroleum oil and coal
because it is reusable.
Q. Why is water not
like coal or petroleum oil? Or, How is water different from coal and oil?
Ans : Coal and petroleum oil exhaust
for ever once they are used. They cannot be savvied or recycled once they are
burnt on the other hand water remains more or less at the same level due to
water cycle prevailing on earth.
Q. Write a short note
on Lithosphere?
Ans : Lithosphere is the hard surface
of the earth which accounts for 29% of the total surface area on the globe. It
is the crust of the earth and it is made up of old a 'ks and minerals mixed up
with various substances. It provide, habitat to all kinds pf plants, animals
and microorganism. Lithosphere holds human civilization and all the man has made.
Q. What are the
divisions of our environment?
Ans : On the basis of
its physical characteristics our environment is divided into:
a. Lithosphere
(land or soil)
b. Hydrosphere
(water bodies)
c. Atmosphere
(air)
d. Biosphere
(Plants and animals)
Q. What is the
importance of air?
Ans : Air is essential for all living
beings in the biosphere. Man cannot live even for few seconds without air. He
breathes 22000 times a day and inhales 16 Kg. of air from the atmosphere. Air
is the store house of oxygen for man and other living beings and of carbon
dioxide for trees and plants without air there will be no rain, cloud, and
snow, fog etc.
Q. How would you explain water cycle?
Ans: Watermoves in the atmosphere in
cyclic order. Water cycle begins with the evaporation of oceans, seas, rivers,
lakes and all other water bodies. Evaporation occurs due to sun heat The vapour
forms cloud in the sky and then comes down to earth in the form of raindrops,
hail stones, dewdrops and snowfall etc.
Q. What is atmosphere and why is it
necessary?
Ans : The gaseous cover that surrounds
the earth on all sides and controls life on it is called atmosphere. It
protects earth's surface from becoming too hot. It filters the solar radiations
and prevents the harmful ultra violet rays from reaching the earth's surface.
Q. What are the main sources of air
pollution?
Ans : Air pollution occurs when
pollutants are released into air. The main air pollutants are automobile
exhaust, industrial smoke, solvent and radioactive radiation and particulates.
Q. What is smog? What harm does it do?
Ans : The word smog has been formed of
smoke and fog. Smog IS a thick layer of Smokey fog that floats over cities.
Smog has occurred over London, Glasgow, Delhi, Chennai, Kolkata. About 3.500 to
4000 people had died in the London smog of 1952. Smog causes respiratory
trouble leading to slow but painful death.
Q. Write a short note on solvents?
Ans : Solvents are used
in paints, polish and sprays. The use of paint, polish etc has been increasing.
Accordingly the use of solvent too is increasing steadily. The spray materials
remain suspended in air for a long time and are very harmful to man. Pesticides
and insecticides contain solvent. They pollute air in rural areas.
Q. What are particulates and what do
they do?
Ans : Particulates are commonly Known
as SPM (Suspended Particulate Matter). They consist of both solid and liquid
tiny particles. They include dust, mist, spray, smoke, fumes etc. Normally
chimneys in factories and power plants pour them out. Particulates create
respiratory problem in, human beings.
Q. What is ozone layer? What is its
function?
Ans : Ozone layer is a gaseous layer in
the atmosphere. It exists about 10 to 60 km above the surface of the earth. It
is like an umbrella that protects the living beings and plants from the
dangerous and harmful Ultra Violet Rays.
49. Who detected the ozone a hole? What
coured it?
Ans : A British Antarctic Survey Team
reported 40% loss in ozone layer. They detected it in 1985. Scientists after
study found that the new threat, the hole in the ozone layer was caused by a
chemical called CFC (Chloro Fluoro Carbon), which is used in modem personal
care products, and Refrigerators.
50. Write a note on Greenhouse and its
usefulness.
Ans :
Green house is made of glass. It is used for growing
plants. During winter season in the
cold countries the insulation is not sufficient for plant growth. The
green house allows visible sunrays to enter into it, but prevent the infrared
rays to go out. Thus gradual warming up takes place inside the green house
favouring growth of the plants.
51. What green house effect?
Ans: The green house
effect means a progressive warming up of the earth's surface due to blanketing
effect of man made corbon dioxide and some other gases in the atmosphere, with
the increasing accumulation of carbon dioxide in the atmosphere global
temperature will increase gradually.
52. What will be the effect of global warming?
Ans : If temperature
riser gradually as a result of global warming the glaciers will melt, the level
of the water bodies like sea and ocean will rise and many low lying areas will
be submerged. The marine ecosystem will be damaged affecting all aquatic life.
53. What is acid rain? What causes it?
Ans: When rain water
contains acid, it is called acid rain. Pollutants like oxide of sulphur,
nitrogen an carbon remain accumulated in the atmosphere. Rain water dissolve
them and transforms them into weak acids and the drops finally come down to
earth in the fortify of acid rain. Amount of acidity depends on the
accumulation of the gases mentioned above.
Q. What are the
effects of acid rain?
Ans : Acid rains are the main cause of
deaths of lakes for which it is called lake killers. Acid rain kills aquatic
lives including plants and animals. It destroys the mineral elements and other
nutrients of soil and adversely affects production. It also affects human
beings and building etc. and other structures.
Q. What are the major
water pollutants?
Ans: When water becomes unfit for
drinking or supporting life due to degradation of its quality it is called
polluted. Industrial wastes, home sewage, run off from mining area or crop
field, hot water from power plants, oil and radioactive wastes are the major
water pollutants.
Q. Show how oil pollutes water?
Ans:. Oil tankers sailing in sea,
sometimes develop leakage or sometimes they meet with accidents. As a result
oil flows down to the surface of the sea water off. Shore drilling also
releases some amount of oil into sea water. The oil spreading in sea water
affects birds other aquatic life. Feathers of aquatic birds are socked in oil
and they die soon.
Q. How does power plants pollute water?
Ans : Fresh water flow is needed in power
plants. Water-cools down the steam condensers. After cooling the condensers the
hot water is released into water bodies, which changes the temperature of the
water. This is called thermal pollution. Changes in temperature of water can
harm fish population. 58. Write a note an earth's environment. Ans :
'Environment' means surrounding. We remain surrounded by various types of
radiations, air, water, soil rocks and minerals which forrrUhe abiotic factors
of the environment. We live interacting with them similarly we remain
surrounded by biotic environment consisting of living organisms. We live
reacting with them and we are inter related with them. Environment affects
size, shape and colour of plants and animals. The environment may also be
responsible for survival of S9me certain organisms. We get our food, clothing
and shelter from our environment. Man also lives in a cultural environment. He
lives surrounded by things he has made. Among the nine planets in the solar
system only the earth has an environment that can life. It is earth's
environment that has made the existence, growth and development of living
beings. Based on its physical characteristics of earth's environment are
divided into: Lithosphere, Hydrosphere, Atmosphere and Biosphere. Biosphere supports
life and it is related to other three spheres.
Q. Write a note on Hydrosphere.
Ans
: Hydrosphere is the water bodies an earth, 71 % of one planet is covered by
the oceans and seas 96.5% of the total water on earth is found in the seas and
oceans, 1.76% of the total water is there in the ice caps and glaciers. 1.70%
is the ground water. Only the balance 0.04% is fresh water. Freshwa ter is
found in the rivers, lakes and streams. Fresh water is not abundant. Still we
do not feel scarcity of water. Because water is not exhaustible source like
coal or petroleum oil. Water cycle on earth keepsthe water level almost steady.
Water cycle, begins with evaporation of sea and ocean water under the heat of
sun. The vapour sails in the sky in the form of cloud and then comes down to
earth as raindrops, dew, fog or snow. Water is an essential life-supporting
element on earth. Besides drinking, water is used for bathing, cleaning,
irrigating, and generating electric power and so on. Much ancient civilization flourished
on riverbanks mainly because of the water streams.
Q. Write a note on atmosphere.
Ans : The atmosphere is a gaseous cover
surrounding the earth. It preserves life on earth. The atmosphere protects life
on earth by way of filtering the sunrays. It prevents the harmful ultra violet
rays of the sun from coming to earth's surface. Air is essential for all types
of life in the biosphere. Man cannot survive even for few seconds without air.
A man breathes 22000 times a day inhaling 16 kg of air from atmosphere. Oxygen
in the air is essential for man and animals while carbon dioxide is essential
for trees and plants. Air is the reservoir of both oxygen and carbon die oxide
and many other gases. Without air there will be no wind, clouds, fire and rain
on earth. Air is a mechanical mixture of several gases. It contains 78.084%
nitrogen, 20.95% oxygen, 0.93% argon and 0.03% carbon dioxide.
***************
Q. Write a note on environmental
degradation.
Ans: Thousands of years ago the primitive
men depended on nature for his food, drinks and shelter. They hunted in'
forests, fished in water and ate wild fruit and thus satisfied their simple
needs. Population grow more and society developed, man changed the natural
habitat to villages, towns and cities, railways, highways, factories and
industries were established with this change from started the process of
environment pollution or degradation. Not only man natural forces also pollute
environment. Earthquake, volcanic eruptions, land-slide, floods. etc degrades
environment. Nature has her own system of recovering minor environment
degradation. When exploitation of Nature by man is unlimited nature fails to
recover. The earth has been facing serious environmental problems during the previous
three decades. Increase in population, spurt in technology aided by mans greed
to get more and more things have polluted air, water and soil. The atmosphere
is so much polluted now that it has paused a threat to mankind and other living
beings. Unless something is done urgently environmental degradation may
endanger all life on earth.
Q. Mention some of the measures to be
adopted for controlling air pollution.
Ans: The following measures should be
adopted for controlling air pollution.
a.
The engines of the automobiles should be
redesigned the emissions at minimum level.
b.
Steps should be taken for (i) regular
servicing of the vehicles, (ii) use of filters, (iii) replacement of old
engines and parts by new one. (iv) proper tuning-ups of the engines should be
done.
c.
Industries should be located at a safe
distance from the residential areas.
d. Traditional
use of fire-wood, coal etc. should be minimized and smoke-free devices should
be used. Forest fires also should be 'Checked,
e. Without
implementation of pollution control system, industries'should not be accorded
permission for production.
f.
There should be greenbelt around towns,
townships and villages. Also there should be green belt around industries.
g.
Railways should use electric engines instead
of coal or steam engines.
h.
There should be strict provision of law
regarding pollution control in case of automobiles and industries.
Q. What is water pollution? Suggest
some of the measures for controlling water pollution.
Ans: When water becomes unfit for
drinking or supporting life due to degradation of its quality. It is said to be
pollution. The industrial wastes, home-sewage, run-off from mining area or crop
fields, hot water from power plants, oil and radioactive Wastes are the major
water pollutants.
Following measures are to be adopted
for controlling water pollution:
a. There
should be strict regulations by Government to the effect that no industry can
release industrial wastes into rivers or streams without proper treatment in
the effluent treatment plant. Production should not be permitted without the
establishment of the treatment plant.
b. Domestic
and other sewage should be treated in sewage treatment plant, and only after
such a treatment it should be allowed to be discharged into water bodies.
c. Use
of chemical pesticides and fertilizers should be limited and only herbal
pesticides should be used.
d. There
should be complete ban an disposal of dead bodies of man and animals into
rivers. River banks should be kept clean.
e. Aquatic
plants should be cleared at short intervals.
f.
Water should be kept purified from harmful
micro organisms by using potassium permanganate.
g. Above
all people should be made aware about the harmful effect of water pollution. So
that they learn to protect themselves from water borne diseases.
Q. Suggest some measures to control of
soil pollution.
Ans : The following measures may be
adopted for control of soil pollution :
·
Municipal and industrial wastes should not
be dumped he~ and there on the soil.
·
There are various methods of treating the
wastes. The treatment of water should be undertaken in such a manner that it
should be economically viable and does riot give rise to new problems.
Composting is the best way for solid wastes treatment. It is a good way to
recycle the resources in the solid wastes and it also makes the soil fertile.
Some new methods of waste disposal
planned and devised in some countries of the World are listed below:
·
The organic part of the wastes are to be
transformed into sugar or proteins.
·
The organic refuse, may be converted into
useful gas like methane.
·
In developed countries, the wastes are burnt
in a specially designed furnace. The heat is used to boil water, which in turn
produces steam which can be used in Industries..
·
Use of degradable plastic bags instead of
non-degradable plastic bags.
·
To plant more and more trees to resist soil
loss by erosion.
·
People in general are made aware of the evil
effects of pollution and they are involved in programmers meant for the
protection of the environment.
Q. Write a note on Greenhouse effect.
Ans : Greenhouse is used for
plant-growing in cold countries. During winter season in the cold countries the
insulation is not sufficient for plant growth. The Greenhouse, made up of
glass, allows visible sunlight to enter into it but prevents the infrared rays
to go out. Thus a gradual wanning up occurs inside it favoring the growth of
the plants. The 'Green house effect' means a progressive wanning up of the
earth's surface due to blanketing effect of man made carbon dioxide and some
other gases in the atmosphere.
As the amount of carbon dioxide in the
atmosphere is increasing day by Jay, Scientists say that the global temperature
will increase gradually. If the temperature rises gradually, the glaciers will
start melting, the level of the water bodies like Sea and Ocean will rise and
many low lying areas will be submerged. The marine ecosystem will be damaged.
So, global warmingis mainly due to increasing Co2 level in the atmosphere.
Industrialization, deforestation and increasing number of fossil-fueled
vehicles on the roads are the principal sources of Co2 increase. Steps should
be taken to minimize the emission of Co2.
Q. What is the definition of pollution
and write briefly about its different types.
Ans : The term pollution have derived
from latin word pollute. Pollute means make dirty. Thus pollution means a
change in the phisycal, chemical and biological aspects of environment. This
pollution is very harmful to human life and all other living bengs. There are
different types of pollution. These are as follows:
(a) Air pollution: Air
is polluted when ar pollutants are released into the air. Air pollution affects
not only human beings, but,also plants, crops and building etc. Mainly
automobile exhausts pollute air. The automobiles and industries release the
pollutants called Sulfer oxides, Nitrogen oxides, Hydrocarbons, carbon monoxide
and particulates.
(b) Water pollution:
Water is called polluted when it becomes unfit for drinking or supporting life,
pollution degrades water. Industrial wastes, home sewage, hot water released by
power plants and radioactive wastes are the main pollutants of water.
Pollutants bring in adverse change in physical, chemical and biological
properties of water. Water pollutants are found in three states. The suspended
pollutants remain floating on water. Dust" mineral, foam, clothes, paper
etc are suspended pollutants. The colloidal pollutants remain mixed up with
water. They are not easily separable. The third type of pollutants remains
dissolved in water. Gasses and minerals belong to this type of water
pollutants. Water pollution may be due to natural canses or it may be man made.
(c) Radiocative
pollution: Radioactive materials pollute atmosphere. They are
released into air by nuclear weapon testing establishments, nuclear reactors,
chemical processing plants, hospitals and research institutes. They release
radio nuclides to the atmosphere, which are really injurious to health.
Radioactivity related activities have, been increasing all over the world
making a serious threat to mankind in future. Explosion of atom bombs in
Nagasaki and Hiroshima in Japan during the Second World War have done great
damage. In spite of its destructive nature nations have been performing nuclear
tests. The radioactive particles remain suspended in, air and finally settle down
on soil or water. Thus radioactive pollutants pollute air, water and soil as
well. Leakage in nuclear reactors also pollute atmosphere and killed many
people in Russia. Radioactive pollutants can cause skin disease, cancer,
respiratory problems, abnormal births and many more problems.
(d) Soil pollution:
Domestic and public wastes, industrial and mining wastes, agricultural wastes,
radioactive materials and biological agents are treaded as soil pollutants.
Pollution degrades soil and changes its physical, chemical and biological properties;
pollution also degrades productivity of soil. Household garbage such as
newspapers, plastic, bottle etc., are heaped here and there. These heaps are
the breeding and growing grounds of germs. These dirty tilings help in
spreading typhoid, dysentery, plague etc. Industrial wastes are carried away by
rainwater,"enter into earth's surface and pollute ground water. They also
pollute atmosphere and cause serious public health problems. Modern
agricultural system is also polluted soil by way of using fertilizers and
chemicals etc. In the same manner radioactive materials and biological gents
like the parasites also pollute soil.
5. Noise pollution:
Noise has been defined as unwanted and unpleasant sound that causer displeasure
to man. Noise causes deafness; sleep lessens, stress and anxiety. It also
affects blood pressure and the working of the heart. The idea of noise differ
from man to man, some people can bear loud noise while others cannot. The unit
of measuring noise is decibel. In the industrial areas in the Indian cities the
range of noise pollution is between 75r90 dB. It is louder in aerodromes,
railway stations and bus terminuses. Noise pollution is primarily made by the
industries.
AIR POLLUTION
Q. What do you mean by air pollution?
Ans :
Air is a mixture of many gases and moisture with some inert materials. When the
quality of the air changes due to presence of other materials in such
concentration as is harmful to men and their environment then it is called air pollution.
Q. What are the
gaseous components of normal air?
Ans : Gaseous components of
normal air are- Oxygen= 20.9% Nitrogen=
79% Carbon-dioxide= 0.03% and a few
other gases are also present in trace amounts.
Q. What do yhou mean
by pollutions? What are the different types of pollutions?
Ans: Any solid, liquid or gaseous
substance present in such concenrtration as may be injurious to the environment
is called pollutant. Any substance which causes pollution is known as
pollutant.
There are two types of pollutants —
(i) Biodegradable pollutants, which are
degraded quickly by biological process, like domestic wastes.
(ii) Non degradable pollutants, which
either donot degrade or degrade very slowly, like heavy metals and toxic, trace
elements.
Q. What are the
material sources of air pollution?
Ans: (i) Carbon
monoxide: It is released by automobiles and by factories where coal is used as
fuel. Excess carbon monoxide in the atmosphere causes serious complication in
man affecting nerve, heart and lungs.
(ii) Sulphur compounds : There are
released due to biological decomposition, volcanic eruption and from factories
using coal and petroleum. Smelting of sulphur areas also release 'sulptiur
dioxide. Sulphur dioxide particularly causes respiratory ailment, headache, eye
irritation etc. S02 reacts with rain water and forms acid rain which
harm plants as well as buildings.
(iii) Nitrogen Oxide : Its main sources
are automobile exhaust, power, generator, anaerobic decomposition of organic
waste. It causes eye and nose irritation and pulmonary discomfort.
(iv) Hydrocarbons : Its important
sources are automobile exhaust, incomplete combustion of fuel, explosives etc.
It causes irritation of eye and mucous membrane, lung cancer etc.
(v) Photochemical : Certain pollutants
mix with other pollutants under the influence of UV radiation and form some
compounds, such as peroxyacetyl nitrate (PAN) Ozone (O) and particulates all
forming photochemical smog. PAN and ozone cause many complication in man like
irritation of eye, caughing headache etc. Ozone also seriously impairs plant
growth.
(vi) Smoking: Tobacco smoking is closed
chambers, buses and trains affects others. Tobacco smoking causes thickening of
epithelial layer and forms precursors of cancerous cells.
Q. What are the particle sources of air
pollution?
Ans : (i) Lead : Automobile exhaust is
the main source of lead pollution. Lead pollution is also caused from painting,
ceramics, pesticides etc. Over exposure to lead interfere with the development
of RBC, disrupt functioning of cells, circulatory and nervous system.
(ii) Cement and other dust : Oment
particles affect plant growth in that the leaves fall prematured and produce
infertile seeds. Domestic and agriculture dust, pollen grains, microbial spores
cause allergy and other con plications in man.
(iii) Fluorides, salts and agricultural
chemicals : Fluoride when released in excess settles down on vegetation. It
causes toxic effect on animals and calcifies theu bones and teeth. Potassium
salts and sodium chloride also affect plants in various ways. Pesticides and
herbicides released from factories greatly affect men' and animals.
Q. What is photochemical smog?
Ans : Photochemical smog
is formed when hydrocarbon and nitrogen oxide mix with other pollutants and
free radicles of oxygen. Nitrogen dioxide impart the brownish colour to the
smog. These chemicals mainly arise from fumes and exhaust of motor vehicles.
The complicated reaction that involves in smog formation is induced by the
sunlight and contains such substances as peroxides, aldehydes, ketones, sulphur
and contains such substances as peroxides, aldehydes, ketones, sulphur
trioxide, some metal particles. Photochemical smog is a serious phenomenon of
gigantic industrial cities.
Q. What is ozone
layer depletion?
Ans : A thin ozone layer of the
stratosphere acts as shield from harmful effect of ultraviolet radiation.Ozone
layer has already become .thinner due to release of various chemicals into the
atmosphere by industries. The most damaging chemicals recognised today are
chlorofluerocarbon compounds used as aerosol propellants and refrigerants.
Considerable thinning of ozone layer has been recorded in USA and UK Thinning
of ozone layer will seriously affect agriculture, climate and human health.
Q. What are the major
industries that cause air pollution?
Ans: The major
industries which cause air pollution are –
a.
Automobile, such as cars, scooters,
locomotives etc.
b.
Industrial processors, such as chemical
plants, paper mills, cement factories, petroleum refineries, cotton mills
rubber factories, plastic factories etc.
c.
Heating plants, such as thermal power plant,
atomic power station, domestic burning of coal etc.
Q. What is green
house effect?
Ans : Continuous burning of fossil fuel
and deforestation change gas balance of the atmosphere, particularly C02
with respect to other gases. It has been estimatted that over the past century,
CO, has increased by 15 percent in the atmosphere. As a result of this,
temperature of the earth is increased causing an effect called green house
effect The earth is hearted by the sum. The heat is radiated back by earth. The
CO around the earth forms an envelope which allows the light to pass but absorb
the heat in the infra-red wavelength. As a result of this, the air around the
earth becomes warm. The warm air reradiate heat back to earth.
Q. What is albedo
effect?
Ans: Contrary to the green house
effect, another effect called albedo effect has also been noticed, this is
cause by addition of solid particles and droples into the atmosphere. These
substances reduce the sunlight reaching the earth and thereby tend to lower the
temperature of the earth.
Q. Write about the
effect of air pollution on man and animals.
Ans: Air pollution affects man as veil
as animals. Some of the bad effects are—
a.
Sulphur dioxide causes respiratory ailment,
headache, eye irritation, irritation of mucus membrane tausing dryness of mouth
and throat.
b.
Hydrocarbons affect mucus membrane,
jronchial tract, lungs, They may cause lung cancer.
c.
Photochemical smog causes severe
complications like coughing, headache, pulmonary congestion.
d.
Oxides of carbon, nitrogen, sulphur often
diffuse into the blood stream and combine with haemoglobin causing reduction in
oxygen transport capacity of the blood.
e.
Pollen grains and fungal sportes cause
allergy. Dust and cotton fibres cause pulmonary troubles and asthma. Mine dust
causes black lung disease. Smoke affects lung.
f.
Lead pollution affects RBC, circulation of
blood and nerves.
g.
Fluoride, particularly affects grazing
animals as it causes toxicity in animals which lead to loss of weight, frequent
diarrhoea etc.
Q. Write about the
effect of air pollution on plants.
Ans: Effect of air
pollution on plants are as follows
a.
Sulphur dioxide, fluorides, hydrocarbon are
mainly
b.
Responsible for damage of chlorophyll with
reduced plant growth.
c.
Decay of plant tissues or necrosis is caused
by fluorides, sulphur dioxide, photochemical smog etc.
d.
Leaf fall, bud fall and discolouration of
flowers are caused by hydrocarbons.
e.
Oxides of nitrogen and fluoride pollution
leads to stunted growth, development of small fruits.
Q. What are the
methods of controlling air pollution?
Ans: Methods of
controlling air pollution are as follows-
a.
Use of settling chambers, bag filter,
electrostatic
b.
Precipitator, gas absorber, catalytic
combustion agents etc.
c.
Chimneys should be raised so tht smoke and
particulate matters are thrown high and are carried by wind for dispersal.
d.
Recycling of harmful chemicals and their
reuse.
e.
Control over use of fuel.
f.
Exhaust emission by automobiles must be
reduced by mechanical means.
g.
Generally, industrial activities should be
located away from residential localities.
h.
Plants which can reduce the toxicity and can
absorb pollutants should be cultivated in great number.
WATER POLLUTION
Q. What do you mean
by water pollution?
Ans : When water contains substances
more than it is wanted or it contains harmful elements, germs or particles,
then the water is called polluted water. The physical and chemical properties
of such water is substantially different from pure water. The degree of
difference, indicates the degree of pollution.
Q. What are the
sources of water pollution ?
Ans : (i) Sewage : Organic and
inorganic wastes are regularly discharged by humans into rivers, lakes, seas
etc. The sewage includes biodegradable waste and minerals, such as nitrates and
phosphate of detergents, sodium, calcium, chloride ions etc. Mixing of
detergents'and other chemicals prevent proper biodegradation process and due to
daily addjtionj of newer quantities, the wastes get accumulated.
(ii) Agricultural Pollution: Inorganic
fertilizer, pesticides, herbicides used in crop field are washed down by rain
water or irrigation water to low lying areas, rivers or lakes, causing water
pollution.
(iii) Industrial Pollution : Various
industries are discharging effluents daily in great quantities which ultimately
find their way into rivers, lakes and seas. Industrial wastes contain chemicals
, such as lead, mercury, deteregents etc.
(iv) Oil Pollution : Oil leaked or
spilled from ail tankers and offshore oil float over the sea water polluting
the water and thereby causing damage to marine ecosystem.
Q. How ground water
get does polluted?
Ans: Ground water is much cleaner and
purer than surface water. About 10 percent of the rural and about 30 percent of
the urban population use ground water for drinking and other purposes. However,
even the ground water are now threatened with pollution from refuse dumps,
septic tanks, agricultural chemical, disposal of industrial effluents which
gradually move down and mix with ground water.
Q. What is BOD?
Ans : BOD means Biological Oxygen
Demand. BOD is a measure of the amount of dissolved oxygen required by bacteria
present in organic waste. More the demand, more is the degree of pollution.
Q. What are the
effects of water pollution?
Ans : The effects of
water pollution are —
(i) Abundance of microbes (ii) Creation
of oxygen deficit in aquatic systems, (iii) Generation of plant nutrients and
accelerated entrophication.
(iv) Algal or water blooms are created.
(v) Thermal pollution.
(vi) Increase of toxic race elements.
Q. What is
entrophication?
Ans : Entrophication of closed water
bodies is a phenomenon of pollution caused by a variety of factors.
Eutrophication denotes the lowering or deterioration of water quality for
domestic, recreational and other purposes. The continuous deposition of organic
debris and its degradation by bacteria releases huge quantity of nutrients and
moreover drainage of nutrients used for agricultural purposes in the nearby
areas increases the level of nutrients further. Under this situation, algae and
higher plants grow vigorously. Due to growth of algae and other plants, more
and more organic matter is deposited raising the floor of the lake.
Q. What is thermal
pollution of water?
Ans: Thermal pollution of water is
caused by discharge of hot water into stream. Some industries use water for
cooling purpose but return this water to the stream at a high temperature. Hot
water affects biotic life in water. Some pathogenic forms may be favoured by
the hot water at the expense of the normal fauna. Thus, ecological balance may
be disturbed by discharge of hot water.
Q. What is mercury
pollution of water?
Ans: Mercury pollution is
one of the major concerns in areas where large number of paper industries are
situated. Paper industries, use fungicides and algicides which contain mercury
compounds Methyl-mercury is a highly persistent pollutant that accumulates in
the food chain.
Q. Write about the
measures to control water pollution.
Ans : (i) Preventive measures :
a. Proper
disposal of sewage so that it does not find its way into water bodies.
b. Abuse
of water must be checked.
c. Discharge
of effluents into rivers, lakes and sea without treatment should be strictly
prohibited.
d.
Oil spill should be prevented.
(ii) Curative
measures :
a. Using
septic tanks, oxidation ponds, filter beds, waste water treatment plants and
sewage treatment plants etc. Solid waste may be removed before water is tipped
into river or sea. The solid waste then can be converted into sludge, which is
a valuable fertilizer.
b. For
drinking purposes, water is purified through various steps including biological
treatment and disinfection.
c.Industrial
water can be made less' polluted before discharge by biological treatment using
water hyacinth. Water hyacinth has remarkable capacity to accumulate poisonous
metals including radioactive substances.
d. Certain
strains of bacteria can reduce the oil spill effect and can use up cyanides and
heavy metals if judiciously used.
e. Scientific
method of recycling all waste materials and effluents can reduce water
pollution to a great extent.
Q. Write about the treatment of waste
water.
Ans: Sewage or polluted water having
organic ' matters can be treated to remove polluting matters. This is done in three
stages.
(i) Primary treatment involves physical
process of removing the suspended matters through screening, sedimentation and
floatation.
(ii) Secondary treatment involves
aeration of the polluted water to activate bacteriological action. Algae supply
oxygen through photosynthesis and then the bacteria decompose the offensive
organic materials and convert them to carbon dioxide, sulphate, nitrate,
phosphorus and water. The bacteria are then killed by chlorine.
(iii)
Tertiary treatment is done to remove phosphate, nitrate, sulphate etc;, from
the water. The water released after all the treatment is considerably pollution
free.
The sludge obtained in primary
treatment can be treated anaerobically for decomposition of the organic
materials which produces excellent fertilizer. Composting is another method of
waste disposal. In the composting process all pathogenic organisms are
destroyed.
Q. Write about the industries and their
pollutants which cause water pollution.
Ans: The industries and their pollutants
which cause water pollution are as follows.
a.
Mining industries: hydrogen sulphide,
ferrous sulphate, sulphuric acid, chlorides, metals, suspended solids.
b.
Steel Industries: Iron cyanide, copper
oxide, chromium, cadmium, mercury, oil phenol etc.
c.
Chemical industries: Various types of acids
and alkalis, sulphate, nitrates of metals, phospherus, silica, dye etc.
d.
Detergent industries: Alkalis, ammonia
compounds, fat and fatty acids, sulphonated hydrocarbons etc.
e.
Paper industries: Bleaching substances,
sulphides, cellulose fibres, organic acids.
f.
Food Industries: Putrefied organic matters,
bacteria etc.
g.
Pharmaceutical industries: Organic solvent
are residues, organic acids, intermediate products of drugs.
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