1

Pollution is the effect of undesirable changes in our

surroundings that has harmful effects on plants, animals and
human beings.

Pollutants include solid, liquid or gaseous substances present

in greater than natural abundance produced due to human
activity, which have a detrimental effect on our environment.

2
 P o l lu ti o n s :
p e s o f
Major ty
P o ll u t i o n
a. Air
r P o l lu ti o n
b . W a te
P o ll u t i o n
c. Soil
a l P o ll u tio n
d. C h e m i c
o l lu t io n
e. Noise P
a r h a z a r d s
f. N u c le
3
 Indian Ambient air quality standards

Concentration in (micro gram) ug /m3

Category Area
SPM SO2 NOX CO

A Industrial and mixed use 500 120 120 5,000

B Residential and rural 200 80 80 2,000

Sensitive (hill stations,

C tourist resorts, 100 30 30 1,000
monuments

4
 Types and Sources of Air Pollution
Natural: Forest fires, pollen, dust storm
Unnatural: Man-made; coal, wood and other fuels
used in cars, homes, and factories for energy
Two categories of pollutants:
Primary Air Pollutant
Harmful substance that is emitted directly into the
atmosphere
Secondary Air Pollutant
Harmful substance formed in the atmosphere when a
primary air pollutant reacts with substances normally
found in the atmosphere or with other air pollutants

5
MAJOR AIR POLLUTANTS

6
 Primary Pollutants

CO CO2 Secondary Pollutants

SO2 NO NO2
Most hydrocarbons SO3
Most suspended particles HNO3 H2SO4
H2O2 O3 PANs
Most NO3− and SO42− salts
Sources Natural Stationary

Mobile

7
EFFECTS OF POLLUTANT ON HUMAN HEALTH
 Exposure to air pollution is associated
with numerous effects on human
health, including pulmonary, cardiac,
vascular, and neurological
impairments.

 The health effects vary greatly from

person to person. High-risk groups
such as the elderly, infants, pregnant
women, and sufferers from chronic
heart and lung diseases are more
susceptible to air pollution.

 Children are at greater risk because

they are generally more active
outdoors and their lungs are still
developing.
8
CONTI…..
 Exposure to air pollution can cause both acute (short-term)
and chronic (long-term) health effects.

 Acute effects are usually immediate and often reversible

when exposure to the pollutant ends. Some acute health
effects include eye irritation, headaches, and nausea.

 Chronic effects are usually not immediate and tend not to be

reversible when exposure to the pollutant ends.

 Some chronic health effects include decreased

lung capacity and lung cancer resulting from
long-term exposure to toxic air pollutants.
9
 CHEMICAL AND PHOTO CHEMICA REACTIONS IN
THE ATOMSPHERE

Formation of smog
Smog is a mixture of smoke and fog in suspended
droplet form. The Brownish smoke like appearance that
frequently forms on clear, sunny days over large cities with
significant amounts of automobile traffic.
Types of smog
There are two types of smog.
1. London smog
2. Los Angles smog (or) Photochemical smog.

10
1. London Smog

It is a coal smoke plus fog. Fog mainly consists of

mixture of SO2 + SO3 + humidity. It is bad in morning hours
and becomes worse after sun rise. This is due to sunlight
induced oxidation of SO2 + SO3, followed by reaction with
humidity giving sulphuric acid and aerosd.
SO2 + (O) SO3
SO3+H2O H2SO4

11
 2. Los Angles Smog (or) Photochemical smog
It is not related to smoke (or) fog.
It is formed by the combination of NO, NO2, CO2, H2O, CO,
SO2 and unburnt hydrocarbon particles.
The important reaction is dissociation of NO2 in sunlight.

12
Hydrocarbon + O2, O, O3, NO2, NO Oxidized
hydrocarbons.

These oxidised hydrocarbons with ozone in the

presence of humidity causes photochemical smog.

Health effects of smog

1. It causes irritation to eyes and lungs.

2. It damages plants.
3. It irritates nose, throat, etc.,
4. It also causes bronchial irritation.

13
Ozone Layer Depletion (Ozone hole)

Ozone is a gas (O3) found throughout the

atmosphere, but most highly concentrated in the
stratosphere between 10 and 50 km above sea level,
where it is known as the ‘ozone layer’.

Importance of ozone layer

Without the ozone layer, life on the earth’s surface

would not be possible. It protects us from the damaging
ultraviolet radiation of the sun. In particular it filters out
UV-B radiation.

14
 Recent evidence has shown that certain parts of the
ozone layer are becoming thinner and ozone ‘holes’ have
developed.

The consequence of any thinning of the ozone layer

is that more UV-B radiation reaches the earth’s surface.

UV-B radiation affects DNA molecules, causing

damage to the outer surface of plants and animals. In
humans it causes skin cancer, and eye disease.

15
 Ozone Depleting Substances
The ozone depleting substances essentially consists
of chlorine or bromine atoms which are extremely
reactive while they are in the free state. The following
gases are accumulated in the atmosphere and are found
to be instruments in ozone depletion.

1. Chloro Fluoro Carbon (CFC)

Sources
Refrigerants (freon) in refrigerators, propellent in
aerosol spray cans, blowing agent, foam plastic blowing
agent.

16
 2. Hydro Chloro Fluoro Carbon (HCFC)
Sources Refrigerants, blowing agents.

3. Bromo Fluoro Carbons (BFC)

Sources Fire extinguishers.

4. Other Chemicals

1. Certain halogen compounds are potential ozone

destroyers upto ten times more powerful than the
CFCs.
2. Sometimes the atmospheric sulphur dioxide is
converted into sulphuric acid which greatly
increases the rate of ozone depletion.
17
18
 Indoor Air Pollutants
Indoor air pollutants are primary air pollutants. The
most important indoor air pollutant is radon gas.

Sources (causes) of indoor air pollutants

1. Radon gas is emitted from the building materials like

bricks, concrete, tiles, etc., which are derived from soil
containing radium.

2. It is also present in natural gas and ground water and is

emitted indoors while using them.

3. Burning of fuels in the kitchen, cigarette smoke, liberates

the pollutants like CO, SO2, formaldehyde, BAP (benzo-(a)
pyrene).
4. Use of Liquidators (mosquito repellents) 19
Controls (methods) for Air pollution

20
SOURCE CONTROL TECHNOLOGY
 Air quality management sets the tools to control air pollutant
emissions.

 Control measurements describes the equipment, processes or

actions used to reduce air pollution.

 The extent of pollution reduction varies among technologies and

measures.

 The selection of control technologies depends on environmental,

engineering, economic factors and pollutant type.

21
1. SETTLING CHAMBERS
 Settling chambers use the force of gravity to remove solid
particles.
 The gas stream enters a chamber where the velocity of the
gas is reduced. Large particles drop out of the gas and are
recollected in hoppers. Because settling chambers are
effective in removing only larger particles, they are used in
conjunction with a more efficient control device.

22

Figure: Settling chambers

 2. CYCLONES
 The general principle of inertia separation
is that the particulate-laden gas is forced
to change direction. As gas changes
direction, the inertia of the particles
causes them to continue in the original
direction and be separated from the gas
stream.
 The walls of the cyclone narrow toward
the bottom of the unit, allowing the
particles to be collected in a hopper.
 The cleaner air leaves the cyclone
through the top of the chamber, flowing
upward in a spiral vortex, formed within a
downward moving spiral.
 Cyclones are efficient in removing large
particles but are not as efficient with
smaller particles. For this reason, they
are used with other particulate control
devices. Figure: Cyclone Collector
23
3. FABRIC FILTERS
 Fabric filters, or baghouses, remove dust from a
gas stream by passing the stream through a
porous fabric. The fabric filter is efficient at
removing fine particles and can exceed
efficiencies of 99 percent in most
applications.

24
Figure: Fabric filter (baghouse) components
CONTI…..
 The selection of the fiber material and fabric
construction is important to baghouse
performance.

 Thefiber material from which the fabric is made

must have adequate strength characteristics at
the maximum gas temperature expected and
adequate chemical compatibility with both the
gas and the collected dust.

 One disadvantage of the fabric filter is that

high-temperature gases often have to be
cooled before contacting the filter medium.
25
 4. ELECTROSTATIC PRECIPITATORS
(ESPS)
 An ESP is a particle
control device that
uses electrical forces
to move the particles
out of the flowing gas
stream and onto
collector plates.

 The ESP places

electrical charges on
the particles, causing
them to be attracted to
oppositely charged
metal plates located in
the precipitator.
Figure: Electrostatic precipitator components
26
CONTI….

 The particles are removed from the plates by "rapping"

and collected in a hopper located below the unit.
 The removal efficiencies for ESPs are highly variable;
however, for very small particles alone, the removal
efficiency is about 99 percent.
 Electrostatic precipitators are not only used in utility
applications but also other industries (for other
exhaust gas particles) such as cement (dust), pulp
& paper (salt cake & lime dust), petrochemicals
(sulfuric acid mist), and steel (dust & fumes).

27
CONTROL OF GASEOUS POLLUTANTS FROM STATIONARY SOURCES

 The most common method for controlling

gaseous pollutants is the addition of add-on
control devices to recover or destroy a
pollutant.
 There are four commonly used control
technologies for gaseous pollutants:
 Absorption,
 Adsorption,
 Condensation, and
 Incineration (combustion)

28
1. ABSORPTION
 The removal of one or more selected
components from a gas mixture by
absorption is probably the most
important operation in the control of
gaseous pollutant emissions.
 Absorption is a process in which a
gaseous pollutant is dissolved in a
liquid.
 Water is the most commonly used
absorbent liquid.
 As the gas stream passes through
the liquid, the liquid absorbs the gas,
in much the same way that sugar is
absorbed in a glass of water when
stirred.
Typical Packed Column Diagram
29
CONTI….

 Absorbers are often referred to as scrubbers, and there

are various types of absorption equipment.

 The principal types of gas absorption equipment

include spray towers, packed columns, spray
chambers, and venture scrubbers.

 In general, absorbers can achieve removal efficiencies

grater than 95 percent. One potential problem with
absorption is the generation of waste-water, which
converts an air pollution problem to a water pollution
problem.

30
2. ADSORPTION

 When a gas or vapor is brought into contact with a

solid, part of it is taken up by the solid. The molecules
that disappear from the gas either enter the inside of
the solid, or remain on the outside attached to the
surface. The former phenomenon is termed
absorption (or dissolution) and the latter adsorption.
 The most common industrial adsorbents are activated

carbon, silica gel, and alumina, because they have

enormous surface areas per unit weight.
 Activated carbon is the universal standard for

purification and removal of trace organic

contaminants from liquid and vapor streams.
31
 Carbon adsorption systems are either regenerative or non-regenerative.
 Regenerative system usually contains more than one carbon bed.

As one bed actively removes pollutants, another bed is being

regenerated for future use.
 Non-regenerative systems have thinner beds of activated carbon.

In a non-regenerative adsorber, the spent carbon is disposed of

when it becomes saturated with the pollutant.

Regenerative Carbon Adsorption Non-Regenerative Carbon

System Adsorption System 32
3. INCINERATION
 Incineration, also known as combustion, is most
used to control the emissions of organic
compounds from process industries.
 This control technique refers to the rapid oxidation of
a substance through the combination of oxygen with a
combustible material in the presence of heat.
 When combustion is complete, the gaseous stream is
converted to carbon dioxide and water vapor.
 Equipment used to control waste gases by
combustion can be divided in three categories:
 Direct combustion or flaring,
 Thermal incineration and
 Catalytic incineration.

33
2. WATER POLLUTION?

The Great Pacific ocean Garbage patch

34
2. WATER POLLUTION
Definition
Water pollution may be defined as, “the alteration
in physical, chemical and biological characteristics of
water which may cause harmful effects on humans and
aquatic life.”

The pollutants include sewage, industrial

chemicals and effluents, oil and other wastes. Besides,
chemicals from the air dissolved in rain water, and
fertilizers, pesticides and herbicides leached from the
land also pollute water.
Types, effects and sources (causes) of
water pollution
Water pollution is any chemical, biological or
physical change in water quality that has a harmful
effect on living organisms or makes water unsuitable for
desired uses.
1. Infectious Agents

Bacteria, viruses, protozoa and parasitic

worms.

Human Sources (causes)

Human and animals wastes.
Effects
Variety of diseases.

2. Oxygen Demanding Wastes (Dissolved oxygen)

Organic wastes such as animal manure and

plant debris that can be decomposed by
aerobic(oxygen-requiring) bacteria.

This degradation consumes dissolved oxygen in

water. Dissolved oxygen (DO) is the amount of oxygen
dissolved in a given quantity of water at a particular
pressure and temperature.
The saturated point of DO varies from 8-15 mg/lit.
Human Sources (causes)

Sewage, animal feedlots, paper mills, and

food processing facilities.

Effects

Large populations of bacteria decomposing

these wastes can degrade water quality by depleting
water of dissolved oxygen. This causes fish and other
forms of oxygen-consuming aquatic life to die.
3. Inorganic chemicals

Water soluble inorganic chemicals

(i) acids,
(ii) compounds of toxic metals such as lead (Pb),
arsenic (As) and selenium (Se) and
(iii) salts such as NaCl in ocean water and fluorides
(F-) found in some soils.

Human Sources (causes)

Surface runoff, industrial effluents and
household cleansers.
Effects

(i) Can make fresh water unusable for drinking or

irrigation.
(ii) Causes skin cancers and neck damage.
(iii) Damage the nervous system, liver and kidneys.
(iv) Harm fish and other aquatic life.
(v) Lower crop yields.
(vi) Accelerates corrosion of metals exposed to such
water.
 4. Organic Chemicals
Oil, gasoline, plastics, pesticides, cleaning
solvents, detergents.

Human Sources (causes)

Industrial effluents, household cleansers,
surface runoff from farms.
Effects
(i) Can threaten human health by causing nervous
system damage and some cancers.
(ii) Harm fish and wild life.
5. Plant Nutrients

Water-soluble compounds containing

nitrate(NO3- ), phosphate (PO43- ) and
ammonium(NH4+ ) ions.

Human Sources (causes)

Sewage, manure, and runoff of

agricultural and urban fertilizers.
Effects

(i) Can cause excessive growth of algae and other

aquatic plants, which die, decay, deplete
dissolved oxygen in water and kill the fish.
(ii) Drinking water with excessive levels of nitrates
lower the oxygen carrying capacity of the blood
and can kill urban children and infants.

6. sediments

Soil, silt, etc.,

Human Sources (causes)
Land erosion.

Effects
(i) Can reduce photosynthesis and cloud water.
(ii) Disrupt aquatic food webs.
(iii) Carry pesticides, bacteria, and other harmful
substances.
(iv) Settle out and destroy feeding and spawning
rounds of fish.
(v) Clog and fill lakes, artificial reservoirs, stream
channels and harbours.
7. Radioactive Materials
Radioactive isotopes of iodine, radon,
uranium, cesium, and thorium.

Human Sources (causes)

Nuclear power plants, mining and processing of

uranium and other ores, nuclear weapons production
and natural sources

Effects
Genetic mutations, birth defects, and
certain cancers.
8. Heat (Thermal Pollution)

Excessive heat

Human Sources (causes)

Water cooling of electric power plants and

some types of industrial plants. Almost half of all
water withdrawn in United States each year is for
cooling electric power plants.
Effects

1. Lowers dissolved oxygen levels and makes aquatic

organisms more vulnerable to disease, parasites and
toxic chemicals.
2. When a power plant first opens or shuts down for
repair, fish and other organisms adapted to a
particular temperature range can be killed by the
abrupt change in water temperature known as
thermal shock
9. Point and Non-point Sources of Water Pollution

1. Point Sources
Point sources are discharged pollutants at
specific locations through pipes, ditches or sewers into
bodies of surface water.

Includes factories, sewage treatment plants,

abandoned underground mines and oil
tankers.
2. Non-point sources

They are usually large land areas or air sheds

that pollute water by runoff, subsurface flow or
deposition from the atmosphere. Location of which
cannot be easily identified.

Include acid deposition and runoff of

chemicals into surface water from
croplands, livestock feedlots, logged forests,
urban street, lawn, golf courses and parking
lots.
Water treatment process
1. Zeolite (or) Permutit Process

• Zeolites are naturally occurring hydrated sodium

aluminosilicate. Its general formula is Na2O . Al2O3 .
xSiO2. yH2O . (x = 2 - 10 , y = 2 – 6) .
• Natural zeolites are green sand and non-porous. The
synthetic form of zeolite is known as permutit, which is
porous and possess gel structure, hence it is generally
used for water softening.
• Synthetic zeolite is represented by Na2Ze. The sodium
ions which are loosely held in Na2Ze are replaced by
Ca2+ and Mg2+ ions present in the water.
Process

When hard water is passed through a bed of

sodium zeolite (Na2Ze), kept in a cylinder (Fig. 4.7), it
exchanges its sodium ions with Ca2+ and Mg2+ ions
present in the hard water to form calcium and
magnesium zeolites. The various reactions taking place
during softening process are
Fig. 4.7 Zeolite (or) Permutit process
 The softened water is enriched with large amount
of sodium salts, which do not cause any hardness, but
cannot be used in boiler.

Regeneration

After some time zeolite gets exhausted. The

exhausted zeolite is again regenerated by treating with
10% solution of NaCl.
Advantages of Zeolite process Disadvantages of Zeolite process

1. Turbid water cannot be treated,

1. Water obtained by this because it blocks the pores of the
zeolite bed.
process will have only
hardness of 1-2 ppm. 2. Acidic water cannot be treated,
because it decomposes the
2. This method is cheap, because structure of zeolite.
the regenerated zeolite can
3. Water containing Fe, Mn cannot
be used again. be treated, because
3. No sludge is formed during regeneration is very difficult.
this process. 4. This process cannot be used for
softening brackish
4. The equipment used is
compact and occupies a water, because brackish water
small space. contains Na+ ions. So the ion
exchange reaction will not occur.
5. Its operation is easy.
 2. Ion Exchange (or) Demineralisation process

This process removes almost all the ions (both

anions and cations) present in the hard water.
The soft water, produced by lime-soda and
zeolite processes, does not contain hardness producing
Ca2+ and Mg2+ ions, but it will contain other ions like
Na+, K+, SO42-, Cl- etc. On the other hand DM.
(Demineralised) water does not contain both anions
and cations.
Thus a soft water is not demineralised water
whereas a demineralised water is soft water.
Types of ion exchange resins
This process is carried out by using ion
exchange resins,which are long chain, cross linked,
insoluble organic polymers with a microporous
structure. The functional groups attached to the
chains are responsible for the ion exchanging
properties.

1. Cation exchanger
Resins containing acidic functional groups (-
COOH, -SO3H) are capable of exchanging their H+
ions with other cations of hard water. Cation
exchange resin is represented as RH2.
2. Anion Exchanger
Resins containing basic functional groups (-
NH2, -OH) are capable of exchanging their anions with
other anions of hard water. Anion exchange resin is
represented as R (OH)2.

Process

The hard water first passed through a cation

exchange column, (Fig. 4.8) which absorbs all the
cations like Ca2+, Mg2+, Na+, K+, etc., present in the
hard water.
Fig. 4.8 Ion Exchange (or) Demineralisation process
 The cation free water is then passed through a
anion exchange column, which absorbs all the anions
like Cl-, SO42-, HCO3-, etc., present in the water.
 The water coming out of the anion exchanger is
completely free from cations and anions. This water is
known as demineralised water or deionised water.
Regeneration

When the cation exchange resin is exhausted, it can be

regenerated by passing a solution of dil HCl or dil H 2SO4.

• Similarly, when the anion exchange resin is exhausted,it can be regenerated

by passing a solution of dil NaOH.
Advantages of ion-exchange process Disadvantages of ion-exchange process

1. Highly acidic or alkaline

1. Water containing turbidity,
water can be treated by
Fe and Mn cannot be
this process.
treated, because turbidity
reduces the output and
Fe, Mn form stable
2. The water obtained by this
compound with the resin.
process will have very low
hardness (nearly 2 ppm). 2. The equipment is costly
and more expensive
chemicals are needed.
 Soil Pollution

Cleaning soil pollution is expensive and (usually)

long-term process because it requires advanced
geology, hydrology, chemistry, and even computer
modeling skills.

62
 SOIL POLLUTION
Definition

Soil pollution is defined as, “the contamination of soil by

human and natural activities which may cause harmful effects
on living beings.”
Table :Composition of soil

Sr. no Components %
01 Mineral matter
45
(inorganic)
02 Organic matter 5
03 Soil water 25
04 Soil air 25
Types, effects and sources (causes) of
soil pollution

Soil pollution mainly results from the

following sources

1. Industrial wastes.
2. Urban wastes.
3. Agricultural practices.
4. Radioactive pollutants.
5. Biological agents.
1. Industrial wastes
Disposal of industrial wastes is the major
problem for soil pollution
Sources

The industrial pollutants are mainly discharged from

the various origins such as pulp and paper mills,
chemical industries, oil refineries, sugar factories,
tanneries, textiles, steel, distilleries, fertilizers,
pesticides, coal and mineral mining industries, drugs,
glass, cement, petroleum and engineering industries
etc.,
Effect
These pollutants affect and alter the chemical and
biological properties of soil. As a result, hazardous
chemicals can enter into human food chain from the soil
or water and disturb the biochemical process and finally
lead to serious effects on living organisms.

2. Urban wastes

Urban wastes comprises both commercial and

domestic wastes consisting of dried sludge of sewage. All
the urban solid wastes are commonly referred to as refuse.
Constituents of urban refuse

This refuse contains garbage and rubbish

materials like plastics, glasses, metallic cans, fibres,
paper, rubbers, street sweepings, fuel residues, leaves,
containers, abandoned vehicles and other discarded
manufactured products.

Urban domestic wastes though disposed off

separately from the industrial wastes, can still be
dangerous. This is so because they cannot be easily
degraded.
3. Agricultural practices

• Modern agricultural practices pollute the soil to a

large extent. Today with the advancing agro-

technology, huge quantities of fertilizers, pesticides,
herbicides, weedicides are added to increase the
crop yield.
• Apart from these farm wastes, manure, slurry,
debris, soil erosion containing mostly inorganic
chemicals are reported to cause soil pollution.
 4. Radioactive pollutants
Radioactive substances resulting from explosions
of nuclear dust and radioactive wastes (produced by
nuclear testing laboratories and industries) penetrate the
soil and accumulate there by creating land pollution.

1. Radio nuclides of radium, thorium, uranium, isotopes of potassium (K-

40) and carbon (C-14) are very common in soil, rock, water and air.
2. Explosion of hydrogen weapons and cosmic radiations induce neutron,
proton reactions by which nitrogen (N-15) produces C-14. This C-14
participates in the carbon metabolism of plants which is then
introduced into animals and man.

3. Radioactive waste contains several radio nuclides such as Strontium-90,

Iodine-129, Cesium-137 and isotopes of iron which are most injurious.
Sr-90 gets deposited in bones and tissues instead of calcium.
 5. Biological agents
Soil gets large quantities of human, animal and
bird’s excreta which constitute the major source of
land pollution by biological agents.

1. Heavy application of manures and digested sludges could cause

serious damage to plants within a few years. Because the sludges
are containing more live viruses and viable intestinal worms.

2. In addition to these excreta, faulty sanitation, municipal garbage,

waste water and wrong methods of agricultural practices also
induce heavy soil pollution.
Table : Major physico-chemical characteristics of
untreated wastes of Organic chemical industries in Soil

S.No Industry Physico-chemical characteristics

Suspended solids, high or low pH,
Pulp and
1. colour, fibres, BOD, COD, high
paper
temperature, fibres.
Rubber Chlorides, suspended and dissolved
2.
industry solids, variable pH and high BOD.
Acids, alkalis, phenols, resinous
3. Oil refineries
materials and petroleum oils.
Toxic organics and high acidity or
4. Antibiotics
alkalinity.
S.No Industry Physico-chemical characteristics
Synthetic High suspended and dissolved
5.
drugs organic matter including vitamins.
Very high COD, low pH, high
organic matter, high suspended and
6. Distillery
dissolved solids containing nitrogen,
high potassium.
Organic
Toxic compounds, phenols, high
7. chemical
acidity, alkalinity.
industry
Table : Major physico-chemical characteristics of
untreated wastes of Inorganic chemical industries in Soil

S.No Industry Physico-chemical characteristics

Thermal
Heat, heavy metals, dissolved solids
1. Power
and inorganic compounds.
Plants
Acids, phenols, low pH, alkali,
limestone, oils, fine suspended
2. Steel Mills
solids, cyanides, cyanates, iron salts,
ores and coke.
Cotton Sodium, organic matter, colour, high
3.
Industry pH and fibres.
S.No Industry Physico-chemical characteristics
4. Metal Plating Metallics, toxic cyanides, cadmium,
chromium, zinc, copper, aluminium
and low pH.
5. Iron Foundry Coal, clay, suspended solids and
iron.
6. Pesticides Aromatic compounds, acidity and
high organic matter.
7. Acids Low pH and organic content.
8. Tanneries Calcium, chromium, high salt
content, colour, dissolved and
suspended matter.
9. Explosives Alcohol, metals, TNT and organic
acids.
 Control measures of soil pollution
1. Control of Soil erosion
Soil erosion can be controlled by a variety of
forestry and farm practices.
(a) Trees may be planted on barren slopes.
(b) Contour cultivation and strip cropping may be practiced instead of
shifting cultivation.
(c) Terracing and building diversion channels may be undertaken.

Reducing deforestation and substituting chemical manures by animal

wastes would also help to arrest soil erosion in the long term. Maintaining
soil productivity is vital and essential for sustainable agriculture.
 2. Proper dumping of unwanted materials

Excess of waste products by man and animals

cause chronic disposal problem. Open dumping is most
commonly practiced method. Recently controlled tipping
is followed for solid waste disposal. The surface so
obtained then can be used for housing or sports field.

3. Production of natural fertilizers

Excessive use of chemical fertilizers and

insecticides should be avoided. Biopesticides should be
used in place of toxic chemical pesticides.
 Organic wastes contained in animals dung
can be used for preparing compost
manure and biogas rather than throwing
them wastefully polluting the soil.

4. Proper Hygienic condition

People should be trained regarding the sanitary habits.

Lavatories should be equipped with

quick and effective disposal methods.
5. Public Awareness

Informal and formal public awareness

programs should be imparted to educate people on
health hazards by environmental pollution.

Mass media, educational institutions and

voluntary agencies can achieve this.

6. Recycling and Reuse of wastes

To minimize soil pollution, the wastes such as

paper, plastics, metals, glasses, organics, petroleum
products and industrial effluents etc., should be
recycled and reused.
 Industrial wastes should be properly
treated at source. Integrated waste
treatment method should be adopted.

7. Ban on Toxic Chemicals

Ban should be imposed on chemicals and

pesticides like DDT, BHC etc., which are fatal to plants
and animals. Nuclear explosions and the improper
disposal of radioactive wastes should be banned
CHEMICAL POLLUTION
Chemical pollution is defined as the presence or increase in our
environment of chemical pollutants that are not naturally present there or
are found in amounts higher than their natural background values.

80
 Types
• Chemical pollutants mostly result from various human activities like
the manufacturing, handling, storing, and disposing of chemicals.
•These occur in industrial places and activities such as oil refineries, coal
power plants, construction, mining & smelting, transportation,
agricultural use of pesticides and insecticides, as well as household
activities.
• In fact, the waste streams from chemical industry are now strictly
controlled and treated before being released into the environment.
• Even though measures were taken to reduce this type of pollution, its
effects are still visible.
• Household chemicals involve a variety of chemical products and mixtures
that can easily become chemical pollutants when released into the
environment.
•Even the everyday detergents are chemical compounds that may pollute
our environment! Read the labels of detergent products to confirm that
they contain a variety of potentially hazardous chemicals.

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Effects of chemical pollutions

•Chemical pollution can involve a variety of health effects from simple digestive
problems to chemical intoxication and sudden death by poisoning.

•Chemical pollution leads to various serious diseases, generally by consuming

poisonous food, drinking highly contaminated water, or breathing highly
contaminated air.

•Chemical intoxication can have severe health effects that may trigger
immediate symptoms and diseases or delayed effects which may appear after
weeks or months since the exposure occurred.

• Various chemical pollutants may accumulate in the aquatic sediments over

longer periods of time. Chemical pollution in the ocean water could pose
serious health risks to the ecosystem and ultimately could cause mild or deadly
chemical intoxication in humans after the consumption of contaminated fish or
seafood.

82
How to control chemical pollution?

How much chemical waste do humans produce? The answer: a lot.

Some organizations estimate the global annual average to exceed 200 million tons.

1. Always Recycle Batteries. This is a tip that cannot be stressed enough.

Batteries are composed of chemicals toxic to flora and fauna, and
some battery materials can be volatile when combined with otherwise
common substances.

2. Be Aware of What’s on Your Face. Much of the cosmetics e industry is

not environmentally friendly. As an example, microbeads
can be mistaken by fish for zooplankton and swallowed, creating a
toxic internal environment in the fish.

3. It May be Clean but is It Green? Cleaning products are potential

marketing trap. Harsh cleaning materials may kill undesirable
bacteria, but they may also harm the health of people.
Disinfectants are essentially pesticides and they can carry with them m
any damaging chemicals.
83
Noise Pollution

84
 NOISE POLLUTION
Definition
Noise pollution is defined as, “the unwanted,
unpleasant or disagreeable sound that causes discomfort
for all living beings.”
Unit of Noise (Decibel)
The sound intensity is measured in decibel (dB), which
is one tenth of the longest unit Bel. One dB is equal to the
faintest sound, a human ear can hear.
Noise level

• Normal conversation sound ranges from 35 dB to 60 dB.

• Impairment of hearing takes place due to exposure to noise of 80 dB or
more.
• Noise above 140 dB becomes painful.

85
Types and sources (causes) of noise
It has been found that environmental noise is
doubling every 10 years. Generally noise is described as,

1. Industrial noise.
2. Transport noise.
3. Neighbor hood noise.

86
 1. Industrial Noise
• Highly intense sound or noise pollution is caused by
many machines.
• There exists a long list of sources of noise pollution
including different machines of numerous factories,
industries and mills.
• Industrial noise, particularly from mechanical saws
and pneumatic drill is unbearable and is a nuisance to
public.

87
 2. Transport Noise

The main noise, comes from transport. It mainly

includes road traffic noise, rail traffic noise and air craft
noise. The number of road vehicles like motors, scooters,
cars, motor cycles, buses, trucks and particularly the diesel
engine vehicles have increased enormously in recent years.

That is why, this form of pollution is gaining

importance, especially in large and over crowded towns
and cities. According to experts, the noise level in most of
the residential areas in metropolitan cities is already
hovering on the border line because of vehicular noise
pollution.

88
 A survey conducted in metropolitan cities has
shown that noise level in Delhi, Bombay and Calcutta is
as high as 90 dB. Inhabitants of cities are subjected to
this most annoying form of transport noise which
gradually deafen them.

3. Neighbor hood Noise

This type of noise includes disturbance from

household gadgets and community. Common noise
makers are musical instruments, TV, VCR, radios,
transistors, telephones, and loudspeakers etc., Ever
since the industrial revolution, noise in environment has
been doubling every ten years.

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 Effect of NOISE pollution

Underlying Effects of Noise Pollution

•The Occupational Safety & Health Administration (OSHA) indicates that even
significant short term loud noise exposure can temporarily disrupt a person's ability to
hear and cause tinnitus, which is a ringing sensation within the ears. However, noise
pollution has many subtler biological effects.
•Conserve Energy Future (CEF) links noise pollution to a wide range of health
consequences, including cardiovascular problems, stress, high blood pressure, and
various sleeping disorders. However, CEF also emphasizes the psychological
consequences of noise pollution, which can include fatigue and an increase in
aggressive behavior.
• A study from the British Medical Bulletin (BMB) indicated that noise pollution can
affect people's performance on various tasks.
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Measures for control of NOISE pollution

•Turn off Appliances at Home and offices. ...

•Shut the Door when using noisy Machines. ...
•Use Earplugs. ...
•Lower the volume. ...
•Stay away from Noisy area. ...
•Follow the Limits of Noise level. ...
•Control Noise level near sensitive areas. ...
•Go Green by planning trees.
•Create Healthy noise to eliminate unwanted noise
•Use Noise absorbents in noisy machineries
•Use Proper Lubrication and Better maintenance
•Notify Authorities about Disobedience of Noise Rules
•Regularly check noise levels
Rs. 2299/-
Up to 5000/-
Noise dosimeter
The most common instruments used for Window AC= 35 dB
measuring noise are the sound level meter
(SLM),

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Few home appliances and noise Anything over 85 decibels can harm your
hearing
•coffee grinder: 70-80 db
•Refrigerator: 50 db
•flush toilet: 75-85 db
•electric toothbrush: 50-60 db
•pop­-up toaster: 80 db
•washing machine: 50­-75 db
•doorbell: 80 db
•air conditioner: 50-75 db
•ringing telephone: 80 db
•electric shaver: 50-80 db
•food processor: 80-90 db
•dishwasher: 55-75 db
•blender: 80-90 db
•sewing machine: 60 db
•juicer: 80-90db
•vacuum cleaner: 60-85 db
•garbage disposal: 80-95 db
•hair dryer: 60-95 db
•electric drill: 95 db
•power lawn mower: 65-95 db
•leaf blower: 110 db
•alarm clock: 65-80 db
•hammer on nail: 120 db
•TV audio: 70 db

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 Table Ambient Noise Level dB.

Zone Day-time Night-time

Silent zone 50 40

Residential zone 55 45

Commercial zone 65 55

Industrial zone 70 70

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 NUCLEAR HAZARDS (POLLUTION)
(Radio Active pollution)
• Radiation hazard in the environment comes from ultraviolet,
visible, cosmic rays and microwave radiation which produce genetic
mutations in man.
• Nuclear energy is used to produce clean electric power. The energy
released in the splitting of nuclei in the atoms is used to generate
electricity.

•Number of Operable Reactors Worldwide

Around 11% of the world's electricity is generated by about 450 nuclear

power reactors. About 60 more reactors are under construction,
equivalent to about 15% of existing capacity.
•As of June 18, 2019, there are 59 commercially operating nuclear power
plants with 97 nuclear reactors in 29 U.S. states. Of these nuclear plants,
33 plants have two reactors and 3 plants have three.

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 Sources of Nuclear Hazards
Various sources of nuclear hazards are grouped into two types

1. Natural sources. 2. Man-made (Anthropogenic) sources.

1. Natural sources
(a) The very important natural source is space, which emit cosmic
rays.

(b) Soil, rocks, air, water, food, radioactive radon-222 etc., also
contain one or more radioactive substances.

2 . Man-made sources

Man-made sources are nuclear power plants, X-rays, nuclear

accidents, nuclear bombs, diagnostic kits, etc., where radioactive
substances are used.

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 Effects of Nuclear Hazards
Radiation pollution of the environment is one of the
most horrible ecological crisis to which we are subjected
severely.
• Radioactive radiation affects the cells in the body and the
function of glands and organs.

• People suffer from blood cancer and bone cancer if exposed

to doses around 100 to 1000 roentgens.

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 Control Measures from Nuclear Hazards
1. Nuclear devices should never be exploded in air.

2. In nuclear reactors, closed-cycle coolant system with gaseous

coolants may be used to prevent extraneous activation products.

3. Containments may also be employed to decrease the radioactive

emissions.

4. Production of radioisotopes should be minimized

5. Minimum number of nuclear installations should be

commissioned.

6. Fission reactions should be minimized as the rate of decay of

radionuclides.
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Disposal of Radioactive wastes (Nuclear
Hazards)
Since nuclear wastes are extremely dangerous the way in
which they are disposed is strictly controlled by international
agreement.
Classification of radioactive wastes
The nuclear wastes are usually classified into three
categories.

1. High level wastes (HLW)

2. Medium level wastes (MLW)

3. Low level wastes (LLW)

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 SOLID WASTE MANAGEMENT (OR)
SOIL WASTE MANAGEMENT (OR)
WASTE SHED MANAGEMENT

Rapid population growth and urbanization in

developing countries have led to the generations of
enormous quantities of solid wastes and consequential
environmental degradation.

An estimated 7.6 million tonnes of municipal

solid waste is produced per day in developing
countries.

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 These wastes are disposed in open dumps
creating considerable nuisance and environmental
problems.

These are potential risks to health and to the

environment from improper management of solid
wastes.

Management of solid waste is therefore, become

very important in order to minimize the adverse effects
of solid wastes.

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Types and sources of solid wastes
Depending upon the nature, solid wastes can
be broadly classified into three types
1. Urban (or) Municipal wastes.
2. Industrial wastes.
3. Hazardous wastes.

I. Sources of Urban (Municipal) Wastes

Urban or municipal wastes include the

following wastes
1. Domestic wastes: It contains a variety of
materials thrown out from the homes.

Food waste, cloth, waste paper, glass

bottles, polythene bags, waste metals,
etc.,

2. Commercial wastes: It includes the wastes coming

out from the shops, markets, hotels, offices, institutions,
etc.,

Waste paper, packing material, cans,

bottle,polythene bags, etc.,
3. Construction wastes: It includes the wastes of
construction materials.
Wood, concrete, debris etc.,

4. Biomedical wastes: It includes mostly the waste organic

materials.
Anatomical wastes, infectious wastes, etc.,

Type and characteristics of Urban (municipal) Wastes

(a) Bio-degradable wastes: The urban solid waste
materials, that can be degraded by micro organisms are
called biodegradable wastes.
 Food, vegetables, tea leaves, egg
shells, dry leaves, etc.,

(b) Non - Biodegradable wastes: The urban solid waste

materials that cannot be degraded by micro organisms
are called non-biodegradable wastes.

Polythene bags, scrap metals,

glass bottles, etc.,
 II. Source and Characteristics of Industrial Wastes
The main sources of industrial wastes are chemical
industries, metal and mineral processing industries.

1. Nuclear power plants: It generates radioactive wastes.

2. Thermal power plants: It produces fly ash in large
quantities.
3. Chemical industries: It produces large quantities of
hazardous and toxic materials.
4. Other industries: Other industries produce, packing
materials, rubbish, organic wastes, acids, alkalis, scrap
metals,rubber, plastic, paper, glass, wood, oils, paints,
dyes, etc.,
III. Hazardous Wastes
Hazardous wastes are the wastes, that pose a
substantial danger immediately or over a period of time
to human, plant or animal life.

Sources of Hazardous wastes

Chemical manufacturing companies, petroleum

refineries, paper mills, smelters, radioactive substances,
biological wastes and other industries.
 Types and characteristics of hazardous wastes

1. Toxic wastes: These are poisonous even in very small

or traces amounts.
(a) Acute toxicity: These wastes have immediate effect on
humans or animals causing death.
(b) Chronic toxicity: These wastes have long-term effect
slowly causing irreparable harm to the exposed persons.
It is much more difficult to determine.
2. Reactive wastes: These wastes react vigorously with
air, water, heat and generate toxic gases.

Gun powder, nitroglycerine, etc.,

3. Corrosive wastes: These wastes destroy materials
and living tissues by chemical reaction.
Acids and bases
4. Radioactive wastes: These are from nuclear power
plants and persist in the environment for thousands of
years.
5. Infectious wastes: It causes infection to others.

Used bandages, human tissue from

surgery,hypodermic needles, etc.
6. Heavy metals: Lead, mercury and arsenic are
hazardous substances.
 Effect of Solid Wastes (or) Effect of
Improper Solid Waste Management

1. Due to improper disposal of municipal solid wastes

on the road side and their immediate
surroundings, biodegradable materials undergo
decomposition. This produces foul smell and
breeds various types of insects, which spoil the
land value.
2. Industrial solid wastes are the sources of toxic
metals and hazardous wastes, which affect the soil
characteristics and productivity of soils when they
are dumped on the soil.
3. Toxic substances may percolate into the ground and
contaminate the ground water.
4. Burning of some of the industrial wastes (or) domestic
wastes (like cans, pesticides, plastics ,radio active
materials, batteries) produce furans ,dioxins and
polychlorinated biphenyls, which are harmful to
human beings.
Process of Solid Waste Management (or)
Process of preventing solid waste generation
in urban areas (or) Waste Shed Management
Solid waste management includes, the waste
generation, mode of collection, transportation, segregation
of wastes and disposal techniques.
 Steps Involved in Solid Waste Management (or)
Waste Shed Management

Two important steps of solid waste (waste shed)

management is Reduce, reuse and recycle, before
destruction and safe storage of wastes.

I Reduce, Reuse and Recycle (3R)

1. Reduce the usage of raw materials

If the usage of raw materials are reduced,

the generation of waste also gets reduced.
 2. Reuse of waste materials

(a) The refillable containers, which are discarded after

use, can be reused.
(b) Rubber rings can be made from the discarded cycle
tubes, which reduces the waste generation during
manufacturing of rubber bands.

3. Recycling of materials

Recycling is the reprocessing of the discarded

materials into new useful products.
Flow Chart

113
(a) Old aluminum cans and glass bottles are melted and
recast into new cans and bottles.
(b) Preparation of cellulose insulation from paper.
(c) Preparation of fuel pellets from kitchen waste.
(d) Preparation of automobiles and construction materials
from steel cans.
The above process saves money, energy ,raw materials and
reduces pollution.
II Discarding wastes
For discarding solid wastes the following
methods can be adopted.
Methods of disposal of Solid Waste

1. Landfill
2. Incineration
3. Composting

1. Landfill

Solid wastes are placed in sanitary landfill system

in alternate layers of 80cm thick refuse, covered with
selected earth fill of 20cm thickness. After two or three
years, solid waste volume shrinks by 25-30% and the
land is used for parks , roads and small buildings.
 The most common and cheapest method of waste
disposal is dumping in sanitary land-fills which is
invariably employed in Indian cities. Land-fill structure
is built either into the ground or on the ground into which
the waste is dumped.

The method involves spreading the solid waste on

the ground , compacting it and then covering it with soil
at suitable intervals.
 Advantages Disadvantages

1. It is simple and economical. 1. A large area is required.

2. Segregation not required. 2. Since land is available away

from town, transportation cost is
3. Land filled areas can be heavy.
reclaimed and used for 3. Bad odors, if land fills are not
other purposes. properly managed.

4. Converts low-lying, marshy 4. The land filled areas will be the

waste-land into useful sources of mosquitoes and flies
and hence insecticides and
areas. pesticides are to be applied at
5. Natural resources are regular intervals.
returned to soil and 5. Causes fire hazard due to the
recycled. formation of methane in wet
weather.
 2. Incineration (or) Thermal process

It is a hygienic way of disposing solid waste. It

is more suitable if the waste contains more hazardous
material and organic content.

It is a thermal process and is very effective for

detoxification of all combustible pathogens.

It is an expensive technology compared to land-

fill and composting because incinerators are costly.
 In this method the municipal solid wastes are
burnt in a furnace called incinerator. The combustible
substances such as rubbish, garbage, dead organisms
and the noncombustible matter such as glass,
porcelain, metals are separated before feeding to
incinerators.

The noncombustible materials can be left out

for recycling and reuse. The left out ashes and
clinkers from the incinerators may be accounted for
only about 10 to 20% which need further disposal
either by sanatory landfill or by some other means.
 The heat produced in the incinerator during the
burning of refuse is used in the form of steam power
for generation of electricity throughout turbines.

The municipal solid waste is generally wet but

has a very high calorific value so it has to be dried up
first before burning. The waste is dried in preheated
from where it is taken into large incinerating furnace
called destructors which can incinerate about 100 to
150 tones per hour.

The temperature normally maintained in a

combustion chamber is about 7000C and may be
increased to about 10000C when electricity is to be
generated.
Advantages Disadvantages

1. The residue is only 20-25%

of original weight, the 1. Its capital and operating cost is
high.
clinker can be used after
treatment. 2. Needs skilled personnel.
3. Formation of smoke, dust and
2. It requires very little space.
ashes needs further disposal, due
3. Cost of transportation is to which air pollution may be
caused
not high as incinerators
located within city limits.

4. Safest from hygienic point

of view.
5. An incinerator plant of
300 tones per day capacity
can generate 3MW of
power.
 3. Composting

• It is another popular method practiced in many cities in our

country. In this method, bulk organic waste is converted into a
fertilising manure by biological action.
• The separated compostable waste is dumped in underground earthern trenches
in layers of 1.5 m and is finally covered with earth of about 20 cm and left over
for decomposition.
• Sometimes certain microorganisms such as actinomycetes are introduced for
active decomposition.
• Within 2 to 3 days biological action starts, the organic matters are being
destroyed by actinomycetes and lot of heat is liberated increasing the
temperature of the compost by about 750C and finally the refuse is converted to
powdery brown coloured odourless mass known as humus and has a fertilizing
value which can be used for agricultural field.
• The compost contains lot of nitrogen essential for plant growth apart from
phosphates and other minerals.
 World Health Organisation (WHO) has set up a
compost plant in New Delhi in 1981 with a capacity to
handle 90 to 100 tonnes of waste everyday. The prepared
compost was supplied to nurseries, kitchen gardens and
horticulture department. The composting technology is
widely employed in developing countries.
Advantages Disadvantages
1. When the manure is added to
1. The non-consumables have to be
soil, it increases the water disposed separately.
retention and ion-exchange
capacity of soil. 2. Use of compost has not yet
2. A number of industrial solid caught up with farmers and
wastes can also be treated by hence no assured market.
this method.
3. It can (manure) be sold thereby
reducing the cost of disposing
of wastes.
4. Recycling – occurs.
 Objectives (or) significance for
prevention of hazardous wastes management
1. Avoid (or) reduce generation of hazardous wastes.

2. Dispose the wastes as close as possible to the place where they

are generated.

3. Manage the wastes in environmentally sound and effective way.

4. Optimise environmentally sound recover of the hazardous

wastes.

5. Prevent illegal international traffic in hazardous wastes.

6. Promoting and strengthening international co-operations in the
management.
7. Promoting the prevention and minimisation of using hazardous
wastes.
8. Reduce to a minimum (or) eliminate the trans boundary
movements.
Pollution Case studies ( from text book)
1. Pesticides pollution in India

125
Pesticide poll…..

126
Pesticide poll….

Read from book page no. 162

127
II case study from Book “River pollution in India Page no 163 & 164

128
River Pollution…….

129
River poll……….

130
• Chernobyl nuclear disaster
(Nuclear pollution )
In April 26, 1986, the melt down of the
Chernobyl nuclear reactor, in Russia, has leaked out the
radioactive rays and radioactive materials.

Effect
1. Nearly 2000 persons have been killed by the
accident.
2. People suffered due to the illness such as,
degeneration of the cells, severe bleeding, anemia ,
skin cancer.
3. Animals, plants are also affected by nuclear
radiation.
PICS.OF CHERNOBYL REACTOR BEFORE
DISASTER

132
PICS.OF CHERNOBYL REACTOR AFTER
DISASTER

133
 FACTS

•On April 26, 1986, a sudden surge of power during a reactor systems test destroyed
Unit 4 of the nuclear power station at Chernobyl, Ukraine, in the former Soviet Union.
The accident and the fire that followed released massive amounts of radioactive
material into the environment.
• How long will it take for Chernobyl to return to normal?
•Chernobyl today. But that's not to suggest that the area has returned to
normal, or will at any point in the near future. Because of the long-lived
radiation in the region surrounding the former Chernobyl Nuclear
Power Plant, the area won't be safe for human habitation for at
least 20,000 years.
• Is there still radioactivity in Chernobyl?
•“The accident released a cloud of radioactive particles and gases,” ANS
noted. ... By all accounts, Chernobyl is still radioactive and still very
dangerous. The cement containment sarcophagus, built amid deadly
radiation by squads of “liquidators” in 1986, is weakening, and a
collapse could turn into a second catastrophe.
134
 •

FUKUSHIMA DAIICHI NUCLEAR DISASTER

•The Fukushima disaster was

the most significant nuclear
incident since the April 26,
1986 Chernobyl disaster and
the second disaster to be given
the Level 7 event
classification of the
International Nuclear Event S
cale
.

135