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ENVIRONMENTAL
POLLUTION
Pollution
• Pollution is the introduction of contaminants into an
environment that causes instability, disorder, harm or
discomfort to the ecosystem .
Types of pollution
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Air pollution
Water pollution
Land or soil pollution
Noise pollution
Thermal pollution
Marine pollution
Nuclear pollution
AIR POLLUTION
• Air pollution is the presence of contaminants
in atmosphere in quantities such that it is
injurious to human, plant animal life and
property.
• Sources of air pollution :
– Natural sources : Volcanic eruption, forest fires,
biological decay.
– Manmade sources :thermal power plant ,fuel
burning, agriculture activities.
Classification of Air pollutants:
1.Primary air pollutants: CO,NO & SO2.
Emitted directly in the atmosphere.
INDOOR AIR POLLUTANTS:
• Radon gas emitted from building materials like
bricks,concrete,tiles etc.,
• It is present in natural gas and ground water.
• burning of fuel in the kitchen,cigaratte, smoke.
2.Secondary air pollutants:HNO3,H2SO4
Primary pollutant may react with one another to
form new pollutants.
Sulphur dioxide:
• The combustion of sulphur containing fuels such as
coal and oil.
• It can be converted into sulphuric acid.
Human Sources :
• Coal burning in power plant (88%)
• Industrial processes (10%)
• Environmental effects :
• In humans : it causes eye irritation, cough, lung
diseases including lung cancer and asthma
• In plants: it causes damage of leaves, bleaching of
chlorophyll which turns leaves brown, damage to
crops and to growth of plants.
Oxides of nitrogen (NOx)
Nitric oxide, nitrogen dioxide and nitrous oxide are
the three main oxides of nitrogen found in the
atmosphere
Sources:
The sources for the oxides of nitrogen are:
• Bacterial decomposition of nitrogenous compounds
• Combustion during lightning : During lightning, oxygen
and nitrogen in the atmosphere combine to give oxides
of nitrogen.
• Industries and automobile exhaust - Air is sucked into the
IC engines. At high temperatures, nitrogen and oxygen in
the air combine to form nitric oxide.
Effects:
The oxides of nitrogen combine with moisture
in the atmosphere to form nitrous and nitric acid.
This leads to increase in the acidity of rain water.
Formation of photochemical smog: oxides of
nitrogen combine with hydrocarbons present in the
atmosphere forming peroxyacyl nitrate.
Control:
Using catalytic converter in automobiles,
Catalytic converters use Pt/ Rh catalyst. the presence
of these catalysts, the oxides of nitrogen are
converted to nitrogen and oxygen .
2NOx ---- N2 + x O2
Carbon monoxide
Sources:
• Cigarette smoking,incomplete burning of fuels.
• Automobile exhaust- carbon monoxide is formed
during the combustion of fuel such as petrol.(77%)
• Industries: carbon monoxide is released by industries
such as iron and steel and petroleum .
CO2 + C ------- 2CO
2CO2
--------- 2CO + O2
Effects:
In humans:
• When the atmosphere is polluted with carbon
monoxide, on inhalation, CO combines with
the hemoglobin to form car boxy hemoglobin
and hence oxygen carrying capacity of the
blood decreases.
• This causes, headache, unconsciousness.
• When inhaled for a long duration it may cause
even death.
• In environment : it increase globe temp.
Lead pollutant:
Sources:
The exhaust from automobiles which use lead
tetraethyl as antiknocking agent.
Paint pigments : Litharge and red lead ( oxides of
lead ) and lead chromate are used as pigments.
These cause lead pollution.
Effects:
• It leads to anaemia and blood cancer in human
beings.
• Lead enters the blood and various organs of the body
including the brain and the Kidneys leading to
dysfunction of the kidney and damage to the brain.
Control of air pollution
Source Control:
• Use only unleaded petrol.
• Use petroleum products and other fuels that have
low sulphur and ash content.
• Reduce the no. of private vehicles
• Ensure the houses, schools are not located on
busy streets.
• Plant trees along busy streets to reduce
particulates, CO and noise.
• Industries should be situated outside the city
• Use catalytic converters to control CO
&hydrocarbons
Control measures in industries
• The emission rates should be restricted to
permissible levels by industries.
• Air pollution control equipments must be
made mandatory.
• Continuous monitoring of the atmosphere
for the pollutants, to know the pollution
levels.
EQUIPMENTS USED TO CONTROL AIR
POLLUTION
• Use sufficient supply of oxygen in combustion
chamber, so that the combustion is complete.
• Use mechanical devices such as
scrubbers, cyclones, bag houses and electrostatic precipitators to reduce particulate
pollutants
Electrostatic precipitator
Bag house filter/cyclone separator
Wet scrubber
WATER POLLUTION
Any alteration in physical, chemical or
biological properties of water, as well as the addition of any
foreign substance makes it unfit for health and which decreases
the utility of water, is known as water pollution.
Definition of effluent: Liquid waste flowing out of a factory,
farm, commercial establishment, or a household into a water body
such as a river, lake, etc.,
Main sources of water pollution are:
• Domestic and municipal sewage
• Industrial waste
• Agricultural waste
• Radioactive materials, etc.,
POINT AND NONPOINT SOURCES
Two types of water pollutants exist;
Point source
Point sources of pollution occur when harmful
substances are emitted directly into water.
e.g.,Oil spill
Nonpoint source.
A non-point source delivers pollutants indirectly
through environmental changes.
e.g., Fertilizer from a field is carried into a stream by
rain
Point Sources
Non Point Sources
Types of pollutant:
1.Infectious agents: Bacteria, viruses, protozoa
source : animal waste.
Effect : variety of diseases
2.Oxygen demanding waste:
Dissolved oxygen (DO) is the amount of oxygen
dissolved in given quantity of water at a particular
P and T. The saturation point 8-15mg/lit.
Sources: Sewage, paper waste, food processing
waste.
Effects: affect to water quality, affect fish survival
and migration.
3.Inorganic chemicals : Acids, pb, arsenic, selenium,
sodium chloride and fluorides.
Causes : surface runoff, effluents
Effects: Cause skin cancer, damage nervous
system,harm to fish and aquatic life, lower crop
yields.
4.Organic chemicals:Oil, gasoline,plastics,
solvents ,detergents.
Causes: Industrial efflents, surface runoff forms.
Effects: Causing effect nervous system ,cancer, harm
fish and wild life.
5.Plant nutrients:
Nitrate, phosphate and ammonium ions
Causes: sewage, runoff water from
agriculture,fertillizer.
Effects: Excessive growth of algae, lower the oxygen
carrying capacity.
6.Sediment: Soil
Causes: Land erosion.
Effects: Can reduce photosynthesis, Affect aquatic
food webs.
Sewage treatment
In primary treatment, the suspended solids
and floating objects are removed using coarse
screens and sieves.
In secondary treatment, the maximum
proportions of the suspended inorganic/
organic solids are removed from the liquid
sewage. The liquid material passes into the
sedimentation tank and finely suspended
particles are allowed to settle by adding
coagulants like Alum.
Tertiary treatment
Remove detergents, metal ions, nitrates and
pesticides, as these are not removed in the
earlier treatments.
The phosphates are removed as calcium
phosphates by adding calcium hydroxide at pH
10-11. At this pH, ammonium salts are also
converted into ammonia.
The effluent is chlorinated to remove
pathogenic bacteria's and finally passed
through activated charcoal to absorb gases.
Control of water pollution:
• Avoid Pesticides and fertilizers on sloped land
areas.
• The nutrient rich water can be used as fertilizer in
the fields.
• Separate drainage of sewage and rain water should
be provided to prevent overflow of sewage with
rain water.
• Planting more trees.
• Use nitrogen fixing plants to supplement the use of
fertilizers.
SOIL POLLUTION
Soil pollution is caused by the presence of humanmade chemicals or other alteration in the natural soil
environment.
This type of contamination typically arises from,
• Application of pesticides and fertilizers
• Percolation of contaminated surface water to
subsurface strata, oil and fuel dumping.
• Discharge of industrial wastes to the soil. The most
common chemicals involved are petroleum
hydrocarbons, solvents, pesticides, lead and other
heavy metals.
Effects of soil pollution:
• Chronic exposure to chromium, lead and other
metals, petroleum, solvents, and many pesticide
and herbicide formulations can be carcinogenic.
• Chronic exposure to benzene leads to
leukemia.(blood cancer)
• Mercury and cyclodienes are known to induce
higher incidences of kidney damage.
• Sewage sludge has many types of bacteria, viruses
and worms which cause types of diseases and also
emits toxic vapours.
• Radioactive fallout cause abnormalities .eg.,
Strontium-90 instead of calcium gets deposited
in the bones.
• Soil contaminants can have significant
deleterious consequences for ecosystems.
• Effects occur to agricultural lands which have
certain types of soil contamination.
• Alteration of metabolism of endemic
microorganisms.
• N & P from fertilizer in soil reach water bodies
with agricultural runoff cause Eutrophication.
• Chemicals contaminates ground water
resources.
• Acids, alkalis, heavy metals affect soil fertility.
Control of soil pollution :
• Effluents should be properly treated before
discharging on the soil.
• Solid waste should be properly collected and
disposed off by appropriate method.
• From the waste, recovery of useful products
should be done.
• Cattle dung should be used for methane
generation.
• Microbial degradation of biodegradable
substance for reducing soil pollution.
NOISE POLLUTION
Definition: Noise Pollution can be defied as unwanted or
unpleasant sounds that causes discomfort for all living
things.
• The various sources of noises are associated with urban
development; road-air and rail transport; Industrial
noise.
• In our country, indiscriminate use of loud speakers,
generator sets and firecrackers has given new
dimensions to the noise pollution problem.
• The commonly used parameter for noise is the sound
level in decibel(dB). Human ears are sensitive in the
frequency range of 20Hz to 20000Hz
Major Noise Sources:
1. Road Traffic:
Road traffic noise is one of the most
widespread and growing environmental problems in
urban area. The impact of road traffic noise on the
community depends an various factors such as road
location and design, land use planning measures,
building design, Vehicle standards and deriver
behavior. Motor vehicle ownership in India has
increased substantially over the last 30 years and
general levels of road traffic noise throughout India
have increased through out the period.
2. Air Traffic:
The extend of aircraft noise impact depends
on the type of aircraft flown, the number of flights
and flight paths. The increase in number of flights, an
important factor is overall noise levels, the led to an
increase in general noise levels associated with air
traffic.
3. Rail Traffic:
The two main sources of noise and vibration
relating to the operation of the rail network is
1. The operation of trains and the maintenance
2. Construction of rail infrastructure.
4.Neighborhood & Domestic Noise:
Other significant source of noise
annoyance is car alarms, building construction
and household noise,Celebrations- religious
function,social and elections.
5.Noise generated by noise levels of 125dB as
per Environmental rules 1999.
Effects:
1. Noise can disturb out work, rest, sleep and
communication.
2. It can damage our hearing and evoke other
psychological, physiological and possibly
pathological reactions.
3.It effects health efficiency and behaviour.It
may cause damage to heart,brain,kidneys and
liver.
4.It causes muscles to contract leading to
nervous breakdown, tension.
5.Change in hormone content of blood, which
turn increase the rate of heart beat.
6.Recently it has been reported that blood is
also thickened by excessive noise.
7. Hearing damage : it can cause permanent
hearing loss.
8.Interferences with man’s communication :In
noise area communication is affected.
The CPCB-The central pollution control board recommended noise
levels.
Sound Source
Sound Level
dB
Subjective Feeling
of Human Beings
Rockets and missiles,
heavy explosives
160
Unbearable
Jet Planes and
cannons,
explosives
140
Unbearable
Aircraft Propeller and
Machine Guns
130
Unbearable
Diesel, steam engine
and
ball mills, crackers
120
Unbearable
Electric saws and
looms,
heavy trucks
110
Unbearable
CONTROL MEASURES OF NOISE POLLUTION:
1.REDUCTION IN SOURCE OF NOISE : Heavy vehicles and
old vehicles may not be allowed in populated
areas.
2. Noise making machines should be kept in
containers with sound absorbing media.
3. Proper oiling will reduce the noise from the
machinery.
4. Use sound absorbing silencers: Silencers can
reduce noise by absorbing sound.
5. Planting more trees having broad leaves.
6. Through law:
sound production is minimized at various
social function.
7. The use of fireworks or fire crackers shall not be
permitted except between 6.00a.m and
10.00p.m.No fireworks or fire crackers shall be
used between 10.00p.m and 6.00a.m.
8. Silence zone in area comprising not less than
100meters around hospitals, educational
institutions ,courts and religious places.
THERMAL POLLUTION
• Energy is the basic necessity for the economic
development of a country.
• The electrical energy is produced in power
plants or generating stations. The conventional
power plants are:
- Steam or Thermal Power station,
- Hydro-electric Power station,
- Nuclear Power station
Steam or Thermal Power station
In the thermal power station, the steam is
produced in the boiler, using the heat released
by the combustion of coal, oil or natural gas.
The steam is used to rotate the steam
turbine (impulse/ reaction).
The steam turbine drives the alternator,
which converts mechanical energy into
electrical energy.10-16oC higher than initial
temp.
Hydro-electric Power station
• Hydroelectricity is the term referring to
electricity generated by hydropower.
• The production of electrical power through the
use of the gravitational force of falling or
flowing water.
• It is the most widely used form of renewable
energy.
Once a hydroelectric complex is constructed, the
project produces no direct waste, and has a considerably
lower output level of the greenhouse gas & carbon
dioxide (CO2).
Nuclear Power station
Nuclear power is produced by controlled
(i.e., non-explosive) nuclear reactions.
Commercial and utility plants currently
use nuclear fission reactions to heat water to
produce steam, which is then used to generate
electricity.
Effects of thermal pollution
• Elevated temperature typically decreases the
level of dissolved oxygen (DO) in water.
• Thermal pollution may also increase the
metabolic rate of aquatic animals.
• A large increase in temperature can lead to the
denaturing of life.-barrier for oxygen penetration
into deep cold water.
• Fish migration is affected due to formation of
various thermal zones.
• Discharge of hot water near the shores can be
disturb and even kill young fishes.
• Toxicity of pesticides ,detergents and chemicals into the
effluent increases with increase in temp.
• The composition of flora and fauna changes.
Control of thermal pollution
• Thermal pollution from industrial sources is generated
mostly by power plants, petroleum refineries, pulp and
paper mills, chemical plants, steel mills and smelters.
• Cooling ponds, man-made bodies of water designed for
cooling by evaporation, convection, and radiation.
• Cooling towers, which transfer waste heat to the
atmosphere through evaporation and/or heat transfer.
• Cogeneration, a process where waste heat is recycled
for domestic and/or industrial heating purposes.
RADIO ACTIVE OR NUCLEAR POLLUTION
• The uncontrolled distribution of radioactive
material in a given environment.
• Radioactive contamination is typically the
result of a spill or accident during the
production or use of radionuclide
(radioisotopes), an unstable nucleus which has
excessive energy.
• Contamination may occur from radioactive
gases, liquids or particles
Effects
• Radioactive contamination can enter the body
through ingestion, inhalation, absorption, or
injection that causes discomfort, diarrhea,
nausea or vomiting, and burns skin and hair
loss.
• The cumulative damage can cause serious
health problems long term, such as cancer,
especially leukemia and Thyroid Cancer.
• For this reason, it is important to use personal
protective equipment when working with
radioactive materials.
Control methods:
• It includes the stoppage of leakage from the
radioactive materials including the nuclear
reactors, industries and laboratories.
• The disposal of radioactive material must be
safe and secure.
• The protective garments must be worn by the
workers who work in the nuclear plants.
• The natural radiation must be at the
permissible limits and they must not cross it.
SOLID WASTE MANAGEMENT:Each household
generates garbage or waste day in and day
out. There are different types of solid waste
depending on their source
Types of solid waste: Solid waste can be
classified into different types depending on
their source:Household waste is generally
classified as,
• Municipal waste
• Industrial waste as hazardous waste
• Biomedical waste or hospital waste
• E waste-Electronic waste
SOURCES OF URBAN AND INDUSTRIAL WASTE:
• Waste from homes:polyethylene bags,Al
cans,glass bottles,waste paper,cloth,food
waste,empty metal.
• Waste from shops:Cans,bottles,waste paper,tea
leaves,packaging material.
• Biomedical waste : discarded medicines,
chemical wastes, disposable syringes, swabs,
bandages and body fluids.
• Construction waste :wood,concrete,cement .,
Industrial waste :Packaging meterial,organic
waste, acid,alkali and metals.
• Solid waste: Rubber,plastic,paper,glass,
wood,oils,paints, dyes,heavy metals,
asbestos.
Effects of solid waste :
• Physicochemical and chemical characteristics
affecting productivity of soils.
• Toxic substance contaminate the ground
water.
• Burning of materials produce dioxins, furans
causes cancer.
TYPES INVOLVED SOLID WASTE MANAGEMENT:
1.REDUCE,REUSE,RECYCLE:
a.Reduce the usage of raw materials:
If usage is reduced,generation of waste also
reduced.
b.Reuse of waste materials:
1.Refillable containers can be reused
2.Discarded cycle tubes can be made into rubber
rings.
c.Recycling of materials:
1.Old Al cans and bottles are melted and recast
into new cans and bottles.
2.Preparation of cellulose insulation from paper
3.Preparation fuel pellets from kitchen waste.
Methods of disposal of solid waste:
a. Landfill :
The bottom is covered with several layers of
clay,plastic & sand –protects ground water
contamination.
• Landfill is covered with clay, sand & gravel.
• Methane gas is collected and used to produce
electricity.
b. Composting:
The biodegradable waste is allowed to
decomposed into oxygen rich medium and
quality rich environment is formed which
improves soil fertility rate.
c. Incineration :Burning of waste at high
temp(700oC -1000oC) in combustion chamber
and used to produce electricity and
incinerate100-150tonnes per hour.
Role of individual in prevention of pollution
Individuals can, however, play an important
role in abatement of air, water, soil or noise
pollution in the following simple manners:
Use low-phosphate, phosphate-free or
biodegradable dishwashing liquid, laundry
detergent, and shampoo.
Use manure or compost instead of
commercial inorganic fertilizers to fertilize
gardens and yard plant.
•
Use biological methods or integrated pest
management to control garden, yard, and
household pests.
•
Don't pour pesticides, paints, solvents, oils,
or other products containing harmful chemicals
down drain or on the ground.
•
Recycle old motor oil and antifreeze at an
auto service center that has an oil recycling
program.
Test water for lead, nitrates,
trihalomethanes, radon, volatile, organic
compounds and pesticides.
Support ecological land-use planning in
your community.
Get to know your local water bodies
and form watchdog groups to help monitor
and protect.
Flood
Flood
Definition: Whenever the magnitude of water
flow exceeds the carrying capacity of the
channel within its bank, the excess of water
over flows on the surroundings causes floods.
Types:
1.Slow kinds: Runoff from sustained rainfall
2.Rapid snow melt exceeding the capacity of a
river's channel.
3.Fast kinds: sudden release of water from dam,
landslide, or glacier.
Effects
1.Primary effects
Physical damage – Can damage any type of
structure, including bridges, cars, buildings,
sewerage systems, roadways, and canals.
2.Secondary effects
• Water supplies – Contamination of water. Clean
drinking water becomes scarce.
• Diseases – Unhygienic conditions. Spread of waterborne diseases.
• Crops and food supplies – Shortage of food crops
can be caused due to loss of entire harvest.
• Trees – Non-tolerant species can die from
suffocation.
• Transport - Transport links destroyed.
Methods of control:
Flood management:
1.Diverting excess water through channel or canals
like river ,lake.
2.Satelite pictures of preflood,flood and post flood
with other information.
3.River networking .
4.Optical and microwave data.
5.Flood warning given by central water comission.
Cyclone
Definition:
A cyclone is an area of closed, circular
fluid motion rotating in the same direction as the
Earth.
• Most large-scale cyclonic circulations are centered on
areas of low atmospheric pressure.
• Cyclones are powerful destructive and active from days
to weak and speed varies 180-500km/hr.
• A broad area of low pressure rotating "counterclockwise" (cyclonically) is also a cyclone.
Occurrence:
1.Tropical cyclone in the warm oceans are formed,
because of heat and moisture.
2. Sea surface temperature must below 25Oc .
3.It move like spinning top at the speed of 10-30km/hr.
4.Indian cyclone occurs during octo-dec or April – may.
Effects:
• Tropical cyclones are responsible for large
amounts of damage to human life,crop,roads,
transport, tanks wherever they strike.
• Slow down the developmental activities of the
sea.
Control:Damage can be reduced but not
completely prevented by doing the following:
•
Boarding up homes and businesses,
strategically placing sand bags, and building
more wind resistant structures.
Cyclone management:
• Satellite images are used by meteorological
department.
• Radar system is used to detect the cyclone
and for cyclone warning.
• For observing exact location of cyclone ,every
half an hour satellite picture are analyzed.
• Its difficult to stop the formation of cyclone,
but the effect minimized by planting more
trees.
Earthquake
•
An earthquake is a sudden vibration caused on
the earth’s surface due to the sudden release of
tremendous amount of energy stored in the rocks
under the earth’s crust.
Causes
• Volcanic eruptions, rockfalls, landslides, and
explosions ,hydrostatic pressure of manmade
water bodies.
• Under ground nuclear testing.
• Decrease under ground water level.
• Its measures by Richter scale.
less than 4 – insignificant,4-4.9 – minor,5-5.9damaging,6-6.9 – destructive,7-7.9 – major,more
than 8 – severe damage.
Effects
• Earthquakes produce deformation of ground
space.
• This includes damage to buildings and in worst
cases the loss of human life.
• The effects of the rumbling produced by
earthquakes usually leads to the destruction of
structures such as buildings, bridges, and dams.
• They can also trigger landslides.
Control:
• To prevent an earthquake hazard the building
should be properly designed.
• Do not construct houses on high risk prone
areas.
• In case of an earthquake move out of the
building and came in the open but not panic.
• Do not use lifts in case of an earthquake.
Tsunami
Tsunami is a series of water waves caused by
the displacement of a large volume of a body of
water, usually an ocean.
Causes :
• Earth quake ,landslide
• Deformation of the sea floor due to the
movement of plates.
• Ordinary wave – 100,tsunami – 500km.
• It travels across the deep sea at very high
velocity of at around 800-900km/hr.
• Velocity decreases ,the height and energy of
wave increases.
• Its height near the sea shore ranges from 1565m
Effects:
The effects of the tsunami on the country
during this period range from destruction damage,
death, injury, millions of dollars in financial loss,
and long lasting psychological problems for the
inhabitants of the region.
Tsunami management :
• Under the water are monitored by sensors.
• If any p changes, sensor send information.
•The information passed through earth stations.
•Warning system are warned of the danger approaching.
•Make the people alert through the media to take all
precautions.
Land slides
Land slides are the process of large
differential movement of two land portion.
OR
A landslide or landslip is a geological
phenomenon which includes a wide range of
ground movement.
Causes:
• Down hill movement of earth cauesd by
rain,forces either increaing top materials.
• Movement of heavy vehicles.
• Earthquake ,shocks,vibrations,cyclone creates
landslides.
• Erosion in the hilly tract due to runoff water.
• Undergroung caves,underground mining
operation.
Effects
• Property damage,
• injury
• death
• adversely affect a variety of water supplies,
• fisheries,
• sewage disposal systems,
• forests, dams, and roadways
Control
• Soil Conservation:
Ways to reduce soil erosion:
Terracing: Terracing reduces soil erosion on steep slopes
by concerting the land into a series of broad, level
terraces. This retains water for crops at each level and
reduces soil erosion by water run off.
Contour Farming: This method is adopted for gently
sloped land. This involves planting crops in rows across
the contour of gently sloped land.
Agro forestry: In this method crops are planted together
in strips or alleys between trees and shrubs that can
provide fruits and fuel wood. The trees and shrubs
provide shade which reduce water loss by evaporation
and preserve soil moisture.
Wind Breaks : Wind breaks and shelter belts or trees are
established to reduce wind erosion and also for
retaining soil moisture
• Unloading the upper parts of the slope.
• Concrete support.
• Draining the surface and subsurface water from sloppy
region.
• Soil stabilization by using quick lime in weak areas.