POLLUTION
POPULATION
1830
- 1 Billion
1930
- 2 Billion ( 100 Years)
1960
- 3 Billion ( 30 Years)
1975
- 4 Billion ( 15 Years)
1987
- 5 Billion ( 12 Years)
1999-
6 Billion (12 Years)
2011
7.1 Billion
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POLLUTED
• AIR
• WATER
• LAND- Solid Wastes, e wastes, Biomedical
wastes
AIR POLLUTION
• GASES
• PARTICULATE MATTER
GASEOUS AIR POLLUTANTS
•
•
•
•
FOSSIL FUELS = CO, CO2
INCOMPLETE COMBUSTION = HYDROCARBONS
AEROSOLS AND REFRIGERANTS= CFC
FOSSIL FUELS WITH SULPHUR= SO2, SO3, H2S,
H2SO4
• TEXTILE BLEACHING = CHLORINE
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………ACID RAIN
• Acid rain is basically rain that has a higher
than normal acid level (low pH).
• Acid gases are produced when fossil fuels like
coal and oil are burned in power stations,
factories and in our own homes.
• Most of these acid gases are blown into the
sky, and when they mix with the clouds –
precipitation become more acidic.
• When we burn fuels, chemicals called
'sulphur' and 'nitrogen' are released into
the air.
• Most of the 'sulphur' comes from power
stations
• Most of the 'nitrogen oxides' come from
car and truck exhausts.
•
• Once in the air, they mix with water
in the air - rain, snow, etc - and are
transformed into different
chemicals called 'sulphur dioxide'
and 'nitrogen oxides', which can be
very dangerous for plants, animals
and people.
Sulphur Dioxide ( SO 2) & Nitrogen Oxides ( Nox)
are the primary causes of acid rain
• Acid rain occurs when these gases react in
the atmosphere with water, oxygen, and
other chemicals to form various acidic
compounds.
• Sunlight increases the rate of most of these
reactions. The result is a mild solution of
sulfuric acid and nitric acid
• In the atmosphere, sulphur dioxide is slowly
oxidized to sulphur trioxide which dissolves
readily in water droplets to form sulphuric
acid.
• SO2 – OXIDISED TO SO3
• SO3+ H2O= H2SO4
• Sulphuric acid is also formed when SO2
dissolves in rainwater:
• SO2 + H2O => H2SO3
• Nitrogen Monoxide when released into the
atmosphere combines with atmospheric
oxygen to form nitrogen dioxide:
2NO + O2 --> 2NO2
• In a series of complex reaction, nitrogen
dioxide combines with oxygen and water
vapour to form nitric acid.
• 4NO2 + 2H2O + O2 --> 4HNO3
Causes of Acid Rain
• Burning coal. Oil and natural gas in
power stations makes electricity, giving
off sulphur dioxide gas.
• Burning petrol and oil in vehicle engines
gives off nitrogen oxides as gases.
• These gases mix with water vapour and
rainwater in the atmosphere producing
weak solutions of sulphuric and nitric
acids – which fall as acid rain.
• Acid rain can travel long distances.
• Often it doesn’t fall where the gas is
produced.
• High chimneys disperse the gases and winds
blow them great distances before they
dissolve and fall to Earth as rain.
• The impact of acid rain in Europe has been
sever and is most noticed in forests of the
northeastern USA
How Acid Rain Affects The
Environment
Trees
•
Acid rain can have terrible effects on a
forest. The acid takes away important
minerals from the leaves and the soil.
• Minerals are like vitamins for trees and
plants. Without them, trees and plants
cannot grow properly. They lose their leaves
and become very weak.
The needles and leaves of the trees turn brown
and fall off.
Trees can also suffer from
• stunted growth;
• have damaged bark and leaves
This makes them vulnerable to weather,
disease, and insects.
FORESTS GERMANY
•
•
1982
1983
1985
8 % DAMAGED
34%
50%
• HIGH ALTITUDE FORESTS ESPECIALLY
VULNERABLE
ACID RAIN
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ACID DEPOSITION
Lakes are also damaged by acid rain.
Fish die – this removes the main source of food
for birds.
Acid rain can even kill fish before they are born
when the eggs are laid and come into contact
with the acid.
• ACID DEPOSITION
• RAINWATER 5.6 Ph
• < 5 pH kills aquatic life
• 18000 DEAD LAKES IN SWEDEN
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Buildings
Acid rain dissolves the stonework and mortar
of buildings (especially those made out of
sandstone or limestone).
It reacts with the minerals in the stone to
form a powdery substance that can be
washed away by rain
Humans
• respiratory problems - Asthma, along with
dry coughs, headaches, and throat irritations
can be caused by the sulphur dioxides and
nitrogen oxides from acid rain.
• Brain damage
• kidney problems,
• and Alzheimer's disease has been linked to
people eating "toxic" animals/plants.
SMOG
• Name comes from a mix of “Smoke”
and “Fog”
• First observed in London during the
industrial revolution
• There are 2 types of smog: Industrial
Smog (London) and Photochemical
Smog (Los Angeles)
Types of Smog
Photochemical Smog
Industrial smog is in the forms of
• dust,
• smoke, soot, ashes,
• asbestos,
• oil,
• lead,
• heavy metals,
• and sulfur oxides.
Photochemical fog
• volatile organic compounds (VOCs) and
• oxygenated nitrogen (NOx) comes from
combustion engines.
• Photochemical smog is air saturated with
ozone, VOCs and aerosol particles
• VOLATILE ORGANIC COMPOUNDS VOC
• METHANE- ENTERIC FERMENTATION AND
ANEROBIC WETLANDS ETC
• METHANE CONCENTRATION IN THE STRATOSPHERE
INCREASES WATERVAPOUR- GREENHOUSE
• FROM PLANTS - TERPENE , ISOPRENE
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• NITROUS OXIDE 320.9 PARTS PER BILLION.
COMPARED TO A PRE-INDUSTRIAL HIGH OF
275PPB
• METHANE CONCENTRATIONS AT 1,789
PARTS PER BILLION COMPARED TO 750 PARTS
PER BILLION (PPB) IN 1800
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• Nitrogen oxides (N2O, NO and NO2) form
a major component of photochemical
smog.
• When they combine with hydrocarbons
in the presence of sunlight, the result is
ozone (O3), the major component of
smog.
Photochemical fogs
Nitrogenous compounds
• NO2+UV= NO + O
• O+O2= O3
• NO+ VOC+O2+UV= O3= OTHER
OXIDANTS REDDISH BROWN SMOG
• PHOTOCHEMICAL OXIDANTS
PHOTOCHEMICAL SMOG33
Green House gases
• CARBON DIOXIDE WAS UP MOST IN 2007.
• IT INCREASED TO 383PPM COMPARED TO A
PRE-INDUSTRIAL HIGH OF 280PPM.
• THE CURRENT RATE OF INCREASES IS
AROUND 2PPM PER YEAR
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