ENVIRONMENT
According Environment Protection Act1986 ,Environment is sum total of water, air , land and interrelationships among themselves and also with the human being, other living organisms and property”.
Environment also define as
1.The surroundings or conditions in which a person, animal, or plant lives or operates.
2. The natural world, as a whole or in a particular geographical area, especially as affected by human activity.
man activity.
3. The natural environment encompasses all living and non-living things occurring naturally on Earth or some region thereof. It is an environment that encompasses the interaction of all living species. Climate, weather, and natural resources that affect human survival and economic activity.
Components of Environment
The environment is the physical and biological habitat that surrounds us, which we can feel by using our five organs.
Two Types-
1. Physical Environment— The physical environment is also called Abiotic Environment.For example air, water, and land etc.
2. Living Environment— all the living organism surrounding ourselves is fall into the category of living environment. This is also called the Biotic Environment.
Earth’s environment can be further subdivided into the following four segments
1. Atmosphere
2. Lithosphere
3. Hydrosphere
4. Biosphere
.
₹299 Atmosphere
Atmosphere creates a protective shell over the earth. The atmosphere, which is a gaseous cover,Protects the earth from cosmic radiations and provides life sustaining Oxygen, the macro nutrient.
Nitrogen and Carbon dioxide needed for photosynthesis.
Structure of the Atmosphere
The atmosphere is broadly divided into four major zones.
1. Troposphere
2. Stratosphere
3. Mesosphere
4. Thermo sphere
1. Troposphere—The troposphere layer is near to the ground level of earth. The composition of gases is nearly same throughout the layer. Most of the naughty activity of weather happens in this layer. The transition layer between troposphere and stratosphere
is called Tropopause.
2. Stratosphere—The layer above the troposphere is called stratosphere where temperature increases with height. These layer is also known as “Ozone layer” because ozone gas is found in higher densities here. Stratosphere is hot layer because ozone absorbs radiant energy from the sun. The transition between the stratosphere and mesosphere is called Stratopause.
3. Mesosphere—Layer above the stratosphere is called mesosphere where temperature decreases with height. This layer is very cold. The transition layer between mesosphere and thermosphere is called Mesopause.
4. Thermosphere—Thermosphere is the layer above the mesosphere. In this layer, temperature increases with height. Here density of air is less and eventually we enter into space.
Lithosphere
The crust of the earth containing rock, soil and sediments is called lithosphere. The soil is composed of inorganic and organic matter and water. The main minerals in lithosphere are composed of the elements silicon, calcium, potassium, aluminum, iron, manganese etc. Theorganic constituents are mainly organic compounds of N, P and S.
Hydrosphere
Hydrosphere layer comprised of 3/4th portion on earth. It mainly contains both surface and groundwater. Major constituents of hydrosphere are oceans, lakes, streams, rivers, water vapor
and glacier. The distribution of water among these resources is as
water source Volume in %
oceans and seas 96-97 %
glaciers and polar ice 2-3 %
Freshwater < 1%
The most common components of hydrosphere
Biosphere
Biosphere encircles the earth’s surface where all the living things exist. This layer extend from 10,000 m below sea level to 6000 m above sea level. The biosphere covers parts of other segments
of the environment viz. Lithosphere, Hydrosphere and Atmosphere. Biosphere is a biological environment where living organism interacting with physical environment for example soil,
water and air.
Ecosystem-
Ecosystem is a complex set of relationship among the living resources, habitats, and residents of an area. Ecosystem consists of plants, animals, birds, water, soil and people. A healthy ecosystem
is called sustainable. This means all the elements in the system is in balance and are capable of reproducing themselves.
Ecology is the study of interrelationship among plants and animals and their interactions with the physical environment.
Ecology Categories-
1. Autoecology— it is the study of an individual species. For example, behavior, adaptation and interaction of a particular species in its own environment. Autoecology is also known as species ecology.
2. Synecology— it is the study of communities and their interaction with the environment.Synecology is also known as ecology of communities.Examples of large eco systems are rain forests, deserts, salt marshes, coral reefs, lakes and ponds, open ocean, grass lands etc.
Types of Ecosystem
The main two kinds of ecosystem are Terrestrial and Aquatic.
Terrestrial Ecosystem
One can find terrestrial ecosystem anywhere except heavily saturated places. It is further classified
into following categories-
1. Forest Ecosystem
• Tropical Evergreen Forest
• Tropical Deciduous Forest
• Temperature Evergreen Forest
• Temperature Deciduous Forest
• Taiga
2. Desert Ecosystem
3. Grassland Ecosystem
4. Mountain Ecosystem
1. Forest Ecosystem— They are the ecosystems in which an abundance of flora, or plants, is seen so they have a big number of organisms which live in relatively small space. Therefore,
in forest ecosystems the density of living organisms is quite high. A small change in this
ecosystem could affect the whole balance, effectively bringing down the whole ecosystem.
(a) Tropical Evergreen Forest: Tropical evergreen forest are areas where mean rainfall of 80 for every 400 inches annually happen. Here forest is dense and it comprises of tall trees of different heights.
(b) Tropical Deciduous Forest: Shrubs and Dense bushes rule along with a broad selection of trees. This type of forest is found in quite a few parts of the world while a large variety of fauna and flora are found there.
(c) Temperate Evergreen Forest: Those have quite a few number of trees as mosses and ferns make up for them. Trees have developed spiked leaves in order to minimize transpiration.
(d) Temperate Deciduous Forest: The forest is located in the moist temperate places that have sufficient rainfall. Summers and winters are clearly defined and the trees shed the leaves during the winter months.
(e) Taiga: It is situated just before the arctic regions, the taiga is de ned by evergreen conifers. As the temperature is below zero for almost half a year, the remainder of the months, it buzzes with migratory birds and insects.
2. Desert Ecosystem— Desert ecosystem is located in the regions where annual rainfall is very less. The area of desert ecosystem is 17% of the total land area on our planet. Due to the extremely high temperature, low water availability and intense sunlight, fauna and
ora are scarce and poorly developed. The vegetation is mainly shrubs, bushes, few grasses and rare trees.
3. Grassland Ecosystem— Grassland ecosystem is located in both the tropical and temperature region of the world. It has variety of grasses, harps, insects depending on climatic conditions and temperature. The grasslands are degraded day by day because of overgrazing.
The two main kinds of grasslands ecosystems are:
(a) Savanna— The tropical grasslands are dry seasonally and have few individual trees.
They support a large number of predators and grazers.
(b) Prairies— It is temperate grassland, completely devoid of large shrubs and trees.Prairies could be categorized as mixed grass, tall grass and short grass prairies.
4. Mountain Ecosystem— Mountain land provides a scattered and diverse array of habitats where a large number of animals and plants can be found. At the higher altitudes, the harsh environmental conditions normally prevail, and only the treeless alpine vegetation can survive. The animals that live there have thick fur coats for prevention from cold and hibernation in the winter months. Lower slopes are commonly covered with coniferous forests.
Natural environment is of crucial importance for social and economic life. We use the living world as
1. A resource for food supply
2. An energy source
3. A source for recreation
4. A major source of medicines
5. Natural resources for industrial products.Human impact the environment in several ways. Common effects are-
Decreased water quality, Increased pollution and greenhouse gas emissions, depletion of natural resources and contribution to global climate change.
Some of these are the direct result of human activities,
whereas others are secondary effects that are part of a series of actions and reactions.
Agriculture
Modern agriculture is responsible for the loss of much wildlife and their habitats , through reduction and fragmentation of habitats and wildlife populations. The drainage of wetlands, the de structure hedgerows and the intensive use of fertilizers and pesticides can all pose a threat to wildlife.
Following are the basic causes of agriculture pollution.
1. Pesticides and Fertilizers— Modern day pesticides & fertilizers have to deal with the local pests that have existed for hundreds of years along with the new invasive species. And so,
they are laden with chemicals that are not found in nature.
Once they has been sprayed, it does not disappear completely. Some of it mixes with the water and seeps into the ground. The rest of is absorbed by the plant itself. As a result, the local streams that are supplied water from the ground become contaminated, as do the
animals that eat these crops and plants.
2. Contaminated Water—Contaminated water used for irrigation is one further source of pollution. Much of the water we use comes from ground water reservoirs, canals and through the rains. While plenty of it is clean and pure water, other sources are polluted
with organic compounds and heavy metals. This happens due to the disposal of industrial and agricultural waste in local bodies of water.
As a result, the crops are exposed to water which has small amounts of mercury, arsenic,lead and cadmium dissolved in it. The process of agricultural pollution becomes harder to
fight when such water poisons the livestock and causes crop failure.
3. Soil Erosion and Sedimentation— Further problems are caused by soil erosion and sedimentation. Soil is comprised of many layers and it is only the topmost layer that can
support farming or grazing. Due to ine cient farming practices, this soil is left open for erosion and leads to declining fertility each year. Whether eroded by water or wind, all this
soil has to be deposited somewhere or the other.
Land Pollution:-
Land pollution means degradation or destruction of earth’s surface and soil,directly or indirectly as a result of human activities. Anthropogenic activities are conducted citing development, and the same affects the land drastically.
Below are the sources of land pollution:
1. Deforestation and Soil Erosion— Deforestation carried out to create dry lands is one of the major concerns. Land that is once converted into a dry or barren land, can never be made fertile again, whatever the magnitude of measures to redeem it are.
Land conversion,meaning the alteration or modification of the original properties of the land to make it use-worthy for a specific purpose is another major cause.
2. Agricultural Activities— With growing human population, demand for food has increased considerably. Farmers often use highly toxic fertilizers and pesticides to get rid off insects,
fungi and bacteria from their crops. However with the overuse of these chemicals, they result in contamination and poisoning of soil.
3. Mining Activities— During extraction and mining activities, several land spaces are created beneath the surface. We constant hear about land caving in; this is nothing but nature’s way of filling the spaces left out after mining or extraction activity.
4. Overcrowded Land Fills—Each household produces tonnes of garbage each year. Garbage like aluminum, plastic, paper, cloth, wood is collected and sent to the local recycling unit.
Items that can not be recycled become a part of the land fills that hampers the beauty of the city and cause land pollution.
5. Industrialization— Due to increase in demand for food, shelter and house, more goods are produced. This resulted in creation of more waste that needs to be disposed of. To meet the demand of the growing population, more industries were developed which led
to deforestation. Research and development paved the way for modern fertilizers and chemicals that were highly toxic and led to soil contamination.
6. Construction Activities— Due to urbanization, large amount of construction activities are taking place which has resulted in large waste articles like wood, metal, bricks, plasticthat can be seen by naked eyes outside any building or office which is under construction.
Waterlogging and its Effect
Water logging refers to the saturation of soil with water. Soil may be regarded as waterlogged when the water table of the groundwater is too high to conveniently permit an anticipated activity,like agriculture. In agriculture, various crops need air (speci cally, oxygen) to a greater or lesser depth in the soil. Water logging of the soil stops air getting in.
1. Depletion of oxygen in root zone and increase of CO2 due to water logging. An aerobic condition adversely affects micro-organisms while harmful organisms proliferate and restrict the plant growth.
2. Physical or chemical and biological activities in the soil are disturbed due to low temp.as a result of water logging. Thus pest and diseases infestation problem arises.
3. Water logging makes field operations difficult on impossible.
4. The adverse effects of water logging get accelerated when the capillary water brings salts from lower horizon of soil or they are present in the ground water used for irrigation.
5. Water logging adversely affect the soil water plant relationship there by creating ecological imbalance.
6. Secondary salinization caused by the salts which are brought up from lower horizon strict the uptake of moisture and nutrients in the plant roots and create toxic effect in the root system.
7. Due to excess soluble salts the physical condition of soil deteriorates. Highly deteriorated alkali soils have very low in filtration rates. Most rainfall goes as runo , causing crop
damages in adjoining area.
8. Crops yields reduced and some times crop failure due to inadequate uptake of moisture and nutrients and due to the injurious effect of salts or deteriorated soil condition.
9. Fodders grown in slat-affected soils may contain high molybdenum in or selenium and low amount of zinc. The nutritional imbalance may cause disease in live stock.
Organic Farming:-
Organic Farming system in India is not new and is being followed from ancient time. It is a method of farming system which primarily aimed at cultivating the land and raising crops in such a way,as to keep the soil alive and in good health by use of organic wastes (crop, animal and farm wastes,aquatic wastes) and other biological materials along with beneficial microbes (biofertilizers) to release nutrients to crops for increased sustainable production in an eco friendly pollution free.
The key characteristics of organic farming include.
1. Protecting the long term fertility of soils by maintaining organic matter levels, encouraging soil biological activity, and careful mechanical intervention.
2. Providing crop nutrients indirectly using relatively insoluble nutrient sources which are made available to the plant by the action of soil micro-organisms.
3. Nitrogen self-sufficiency through the use of legumes and biological nitrogen xation,as well as effective recycling of organic materials including crop residues and livestock manures.
4. Weed, disease and pest control relying primarily on crop rotations, natural predators,diversity, organic manuring, resistant varieties and limited (preferably minimal) thermal,biological and chemical intervention.
5. The extensive management of livestock, paying full regard to their evolutionary adaptations, behavioural needs and animal welfare issues with respect to nutrition, housing,health, breeding and rearing.
6. Careful attention to the impact of the farming system on the wider environment and the conservation of wildlife and natural habitats.
ENERGY:_- Energy is the ability to do work. The word ‘work’ means transferring energy from one place to another. energy is neither destroyed nor created. It can only be changed.
Resources of Energy- Renewable
Non -Renewable
Energy is the ability to do work. All forms of energy are stored in di erent ways. Energy sources
we use every day. These sources are divided into 2 groups.
Non -Renewable Resource-
A nonrenewable resource is a natural resource that cannot be re-made or re-grown at a scale comparable to its consumption. Coal, petroleum, and natural gas . These are called fossil fuels.Nuclear
ssion uses uranium to create energy.
Nuclear energy is a Non- Renewable resource because once
the uranium is used, it is gone.
Example -
1. Oil
2. Coal
3. Natural gas
4. Nuclear
Renewable Resource
Renewable resources are natural resources that can be replenished in a short period of time.
Example
1. Solar
2. Geothermal
3. Wind
4. Biomass
5. Water
6. Wave and Tidal Power
Fossil Fuels
Fossils fuels gives 85% of the world’s commercial energy. Fossil fuels is highly combustible substances formed from remains of organisms from past geologic ages. Fossil fuels we burn today
were formed from the tissues of organisms that lived 100-500 million years ago. Fossil fuels are
produced only when organic materials is broken down in an anaerobic environment , one that has
little or no oxygen. Bottoms of deep lakes, swamps, and shallow seas organic matter is eventually
converted into crude oil, natural gas, or coal. It is said that we are using a million years worth of
geological production every dayCoal energy
Coal is organic matter (woody plant material) that was compressed under very high pressure to
form dense, solid carbon structures.
Subsurface mining
In this case underground deposits are reached by digging networks of tunnels deep underground Strip mining.
Here heavy machinery removes huge amounts of earth to expose and extract the coal removalMountaintop
in some cases, entire mountaintops are cut off to obtain the coal.
Formation of coal as follows
1. Peat is compressed to form lignite , which is also known as brown coal
2. Lignite is compressed and volatile compounds are lost to form bituminous coal –soft coal
3. Bituminous coal is further compressed and heated to form anthracite– hard coal
Solar Energy
It is the Ultimate Renewable Resource. It originates with the thermonuclear fusion reactions occurring in the sun. The surface receives about 47% of the total solar energy that reaches the
Earth. Only this amount is usable.
Advantages of solar energy-
1. All chemical and radioactive polluting byproducts of the thermonuclear reactions remain behind on the sun, while only pure radiant energy reaches the Earth.
2. Energy reaching the earth is incredible. By one calculation, 30 days of sunshine striking the Earth have the energy equivalent of the total of all the planet’s fossil fuels, both used and unused
Disadvantages of Solar Energy
1. Sun does not shine consistently.
2. Solar energy is a diffuse source. To harness it, we must concentrate it into an amount andform that we can use, such as heat and electricity.
Why we should use Solar Energy-
1.Argument that sun provides power only during the day is countered
by the fact that 70% of energy demand is during daytime hours. At night, traditional methods can be used to generate the electricity.
2. Our goal is to decrease our dependence on fossil fuels.
3. Currently, 75% of our electrical power is generated by coal-burning and nuclear power plants.
4. It mitigates the e ects of acid rain, carbon dioxide, and other impacts of burning coal and counters risks associated with nuclear energy.
5. It is pollution free, indefinitely sustainable.
Wind Energy:-
The earth’s winds are caused by pressure differences across the earth’s surface due to uneven heating. An estimated 1% to 3% of energy from the Sun that hits the earth is converted into wind
energy. The principle of wind is simple. The poles receive less energy than the equator does from the sun. Also land heats up and cools down more quickly than the seas. This difference between
the seas and the land causes a global atmospheric convection system.
Local Winds:
During the day the air over the land is heated more than the air over the sea. Opposite during the night.
Day pattern:Wind blows from sea to land
Night patt ern:Wind blows from land to sea
Ocean Thermal Energy
Energy is available from the ocean by
1. Tapping ocean currents
2. Using the ocean as a heat engine
3. Tidal energy
4. Wave energy
ocean energy is replenished by the sun and through tidal influences of the moon’s and sun’s gravitational forces. Near-surface winds induce wave action and cause wind-blown currents at about 3% of the wind speed. Tides cause strong currents into and out of coastal basins and rivers.
Ocean surface heating by some 70% of the incoming sunlight adds to the surface water thermal energy, causing expansion and ow. Wind energy is stronger over the ocean due to less drag,
although technically, only sea breezes are from ocean energy.
1. There can be a 20◦ difference between ocean surface temps and the temp at 1000m
2. The surface acts as the heat source, the deeper cold water acts as a heat sink.
3. Temperature differences are very steady.
4. Florida, Puerto Rico, Hawaii and other pacific islands are well suited to take advantage of this idea, called OTEC (Ocean Thermal Energy Conversion)
Wave Energy:-
Wave power is the transport of energy by ocean surface waves, and the capture of that energy to do useful work —for example, electricity generation, water desalination, or the pumping of water
(into reservoirs). A machine able to exploit wave power is generally known as a wave energy converter (WEC).
Important points-
1.1799: First patent of a device designed to use ocean waves to generate power
2. 1910: First oscillating water column was built by Bochaux-Praceique to power his house
3. 1940s: Yoshio Masuda experimented with many concepts of wave power
4. 2004: Wave power was delivered to an electrical grid for the rst time
Tidal Energy:-
Most of the energy sources we have been discussing derived their energy from the sun originally.
Tides are driven by gravity. Gravity is a force that exists between any two objects based upon their mass and the distance between them
Fg = GmM/R2
where M and m are the masses of the two objects, R is the distance between them and G is the
gravitational constant
Hydropower:-
Electricity produced from the water is called the Hydropower or hydro-electric power. The falling water turns the water wheel or the turbine and electricity is generated. It is the most convenient
and versatile form of energy. It plays a key role in agriculture and industrial development and nation’s growth and productivity can be analyzed through the quantity of its energy consumption.
Since rst ve year plan, India is given much emphasis on generation of hydro-electric power from major hydro and mini hydel projects.
The Major Hydro Electricity Projects in India
Sivsamundra project of the river the Can very in Karnataka was the first major hydro-electric project in Asia. It was constructed in 1902.
Some of the important major hydropower projects are discussed below.
1. Bhakra Nangal Project— The Bhakra Nangal project, on the river the Sutlej, with its four power stations at Nangal, Bhakra, Ganguwal and Kotla is an important hydro power project. It has an installed capacity of 1.2 million KW. It supplies electricity to Punjab, Haryana and Delhi.
2. Damodar Valley Project— The Damodar valley project, with its three hydel power stations at Tilaiya, Matron and Panchet is built on the river the " Damodar. It has an installed capacity of 104 mw (megawaits) electricity. It supplies power to Bihar and West Bengal.
3. Hirakud Dam Project—The major hydro-Electricity power project in Orissa is the Hirakud Dam Project on the river the Mahanadi. Its capacity of generating power is 270.2MW. The Rourkela Steel Plant mainly gets power supply from it.
4. Riband Project— It is essentially a hydroelectric project. It has an installed capacity of 300 MW. On the boarders of Uttar Pradesh and Madhya Pradesh water is stored in form of a large lake and power is generated.
5. Chambal Valley Project—On the river the Chambal, two power houses are constructed, one at Gandhi Sagar Dam in Madhya Pradesh and the other one at Kota in Rajasthan. The total installed capacity from both the power houses is 180 MW.
6. Koyana Hydro Electric Project—It is one of the largest projects in Maharashtra. The water of the Koyana, a tributory of the Krishna is utilized for power generation. The total capacity installed is 540 MW. It supplies electricity mainly to Bombay-Poona industrial belt.
7. Tungabhadra Project—This is a joint collaboration of Andhra Pradesh and Karnataka.The power house is built on the river the Tungabhadra.These are few hydroelectric projects.
8. Gandak hydroelectric Project -This project is on the river
the Gandak, and Parambikulam Aliyar on the river the Periyar.
Biomass:-
Biomass is a Renewable Energy source because the energy it contains comes from the sun.Through the process of photosynthesis, chlorophyll in plants captures the sun’s energy by
converting carbon dioxide from the air and water from the ground into carbohydrates, complex compounds composed of carbon, hydrogen, and oxygen. When these carbohydrates are burned,
they turn back into carbon dioxide and water and release the sun’s energy they contain. In this way, biomass functions as a sort of natural battery for storing solar energy. As long as biomass is
produced sustainable—with only as much used as is grown—the battery will last inde nitely.
From the time of Prometheus to the present, the most common way to capture the energy
from biomass was to burn it, to make heat, steam, and electricity. But advances in recent years
have shown that there are more efficient and cleaner ways to use biomass. It can be converted
into liquid fuels, for example, or cooked in a process called “gasi cation” to produce combustible
gases. And certain crops such as switch grass and willow trees are especially suited as “energy
crops,” plants grown speci cally for energy generation.
Nuclear Fuels
Nuclear energy is energy that is generated through the use of Uranium, a natural metal that
is mined all over the world. Nuclear energy is created through complex processes in nuclear
power stations, and the rst nuclear power station was established in 1956 in Cumbria, England.
Today, many military operations and vessels use nuclear power plants and nuclear energy for
their energy source, and nuclear energy is used in many other capabilities such that it provides
16% of the Earth’s energy requirements.
Environmental Pollution-
Man is one of the species who inhabit the earth.he is the only one who has interfered with various natural processes for use of both biological & physical resources to meet his multiple demands,man
has polluted all the three realms of the earth lithosphere,hydrosphere & atmosphere.it is essential for us to know about environment & its pollution.
Air-Pollution-
Air pollution is the addition of gases, chemicals, and particle matter into the atmosphere. Air pollution primarily comes from burning fossil fuels such as natural gas, petroleum, and coal.
Types of Air Pollution
1. Primary Pollutants: are the one which consist of materials such as dust, gases, liquids and other solid material around that enter the atmosphere through natural and human made activities. The main pollutants are carbon monoxide, sulphuroxide, nitrogen oxides.
2. Secondary Pollutant: consist of primary pollutants which reacted
with each other and makes our air polluted. In megacities, the emissions from road car and industries combine themselves and makes photochemical smoge with the help of light energy from the sun. Also the indoor pollutants have been identified some of the more common indoor air pollutants include smoke from cigarettes and cooking, asbestos etc. At high concentrations, these pollutants can cause dizziness. Headaches, coughing. Sneezing.
Nausea, burning eyes, chronic fatigue like symptoms.
Some indoor pollutants, like asbestos and smoke, can cause disease and premature death
Controlling Air Pollution
1. Rather than controlling air pollution, we should prevent the pollution
2. We must use clean wheels in cars and other auto mobiles
3. We have to use non-pollutant energy like solar energy, wind power and hydro prior
4. We have to control the population growth of the world
5. Encourage mass transit and less polluting forms of transportation (e. g. switch from air
travel to rail travel).
Water Pollution:-
Water pollution occurs when harmful substances are released into the water in large quantities which cause damage to people, wildlife, or habitat or indirectly into water bodies .Water pollution
affects plants and organisms living in the bodies of water; and, in almost all cases the effect is
damaging either to individual species and also to the biological communities.
Water pollution sources
Chemical & other contaminants are basic sources of water pollution.Contaminants may include
organic and inorganic substances.
Effect of Water Pollution
1. Water pollution is a major problem in the global context. It has been suggested that it is
the leading worldwide cause of deaths and diseases, and that it accounts for the deaths of
more than 14,000 people daily.
2. An estimated 700 million Indians have no access to a proper toilet, and 1,000 Indian children
die of diarrhea sickness every day.
3. Some 90% of China’s cities suffer from some degree of water pollution, and nearly 500
million people lack access to safe drinking water.
4. In addition to the acute problems of water pollution in developing countries, industrialized
countries continue to struggle with pollution problems as well.
Interactions between groundwater and surface water are complex. Consequently, groundwater
pollution is not as easily classiffied as surface water pollution.
Inorganic water pollutants include:
1. Acidity caused by industrial discharges (especially sulphur dioxide from power plants)
2. Ammonia from food processing waste
3. Chemical waste as industrial by-products
4. Fertilizers containing nutrients–nitrates and phosphates,which are found in storm water
run off from agriculture, as well as commercial and residential use.
5. Heavy metals from motor vehicles (via urban storm water runo ) and acid mine drainage
6. Silt (sediment) in runo from construction sites, logging, slash and burn practices or land
clearing sites
7. Macroscopic pollution—large visible items polluting the water, may be termed “ oatables"
in an urban storm water context, or marine debris when found on the open seas, and can
include such items as:
8. Trash: (e.g. paper, plastic, or food waste) discarded by people on the ground, and that are
washed by rainfall into storm drains and eventually discharged into surface waters.
9. Nurdles: small ubiquitous waterborne plastic pellets.
10. Shipwrecks: large derelict ships.
Purification of water
Purification of water involves physical, biological and chemical processes such as:
1. Filtration
2. Sedimentation
3. Chlorination
4. Slow sand Filters
5. Activated Sludge
6. Flocculation
• Filtration:Filtration is a mechanical or physical operation which is used for the separation
of solids from uids (liquids or gases) by interposing a medium through which only the
uid can pass.
• Sedimentation: Sedimentation is the tendency for particles in suspension or molecules in
solution to settle out of the fluid in which they are entrained, and come to rest against a
wall.
• Chlorination -the process of adding the element chlorine to water as a
method of water puri cation to make it t for human consumption as drinking water. Water
which has been treated with chlorine is e ective in preventing the spread of water born
disease.
• Slow sand Filters- are used in water puri cation for treating raw water
to produce a potable product. They are typically 1 to 2 metres deep, can be rectangular or
cylindrical in cross section and are used primarily to treat surface water.
• Activated Sludge: Activated sludge is a process dealing with the treatment of sewage and
industrial wastewaters and developed around 1912-1914.Atmospheric air or pure oxygen is
introduced to a mixture of primary treated or screened sewage (or industrial wastewater)
combined with organisms to develop a biological oc which reduces the organic content of
the sewage
• Flocculation: is, in the field of chemistry, a process where colloids come out
of suspension in the form of oc or akes. The action differs from precipitation in that,
prior to occulation, colloids are merely suspended in a liquid and not actually dissolved in
a solution.
Farming solution : Choosing organic options can help to reduce the amount of water
pollution. These items are grown without the use of chemicals. Those chemicals, when
used, enter the water cycle. Organic products don’t introduce those chemicals to the
water cycle.
Soil Pollution-
The introduction of substances, biological organisms, or energy into the soil, resulting in a change
of the soil quality, which is likely to aff ect the normal use of the soil or endangering public health
and the living environment.
Soil contaminants are spilled onto the surface through many different activities. Most of these
are the result of accidents involving the vehicles that are transporting waste material from site of
origin to a disposal site.
Others involve accidents involving vehicles (automobiles, trucks and airplanes) not transport-
ing wastes, but carrying materials, including fuel, that when spilled contaminate the soil.
Marine Pollution
Marine pollution occurs when harmful, or potentially harmful, e ects result from the entry into
the ocean of chemicals, particles, industrial, agricultural and residential waste, noise, or the spread
of invasive organisms. Most sources of marine pollution are land based. The pollution often
comes from nonpoint sources such as agricultural runo , wind-blown debris and dust. Nutrient
pollution, a form of water pollution, refers to contamination by excessive inputs of nutrients. It is
a primary cause of eutrophication of surface waters, in which excess nutrients, usually nitrogen
or phosphorus, stimulate algae growth.
There are ve main kinds of marine pollution, namely:
1. Pollution from land-based sources, such as rivers, estuaries, pipelines and outfall structures;
2. Pollution from exploitation of the mineral resources of the sea-bed;
3. Pollution from ships, i.e. the disposal of wastes or other matter incidental to or derived
from the normal operations of ships;
4. Pollution by dumping, i.e. the deliberate disposal of wastes or other matter from ships,
aircraft, platforms or other man-made structures at sea;
5. Pollution through the atmosphere.
Noise Pollution:-
Noise is “sound without value” or “any noise that is undesired by the recipient”.Thus, the kind of environmental impact of noise pollution is slightly di erent from other kinds of pollution.
Generally, there is much more noise in the urban areas because of larger concentration of
population as well as industrial and other activities like transportation vehicular movements, etc.
Non-industrial sources of noise can come from public address systems for religious or political
propaganda, recreation, hawkers or other street noise. Noise can also arise from the natural
sources like thunder.
Noise as a potent menace can be evaluated in terms of a ‘noise level’ scale, or in decibels (dB).
However, the health hazard is a matter of perceived noise level decibels (pNdB), which according
to the W.H.O.’s prescribed optimum noise level as 45 dB by day and 35 by night; and anything
above 80 dB is hazardous.
noise pollution can be minimized
only through rigorous law and conscious e orts of the law enforcement department.
• Sources of Noise Pollution— The indoor sources of Noise Pollution are loudly played
music stereos, radio, televisions, grinding machines, etc. The outdoor sources of Noise
Pollution commonly referred to as environmental noise comes from airplane, machines,
trains, vehicles, industries, etc.
• Effect on Human Health— It may a ect the mind, health and behaviour. It may cause
physically discomfort and temporary or permanent damage to hearing. It causes headache
and irritability. Loud speakers not only disturb the student in their studies but also the
peace of locality. It may cause deafness, stress and high-blood pressure.
• Effect on Animal Health— Animals suffer badly due to noise pollution. At times, it can
also lead to death. Noise has impact on the living pattern of the animals and it may push
the rare species to extinction. Like humans, they also suffer from temporary or permanent
disability of hearing.
Thermal pollution:
An increase in the optimum water temperature by industrial process (steel factories, electricpower houses and atomic power plants) may be called as “Thermal Pollution." Many industries
generate their own power and use water to cool their generator.
The various causes of thermal pollution are as follows
1. Coal- red Power Plants—Some thermal power plants use coal as fuel. Coal- red power plants constitute the major source of the thermal pollution.
2. Industrial Effiluents—Industries generating electricity require large amount of Cooling
water for heat removal. Other industries like textile, paper, and pulp and sugar industry also release heat in water, but to a lesser extent.
Nuclear Power Plants—Nuclear power plants emit a large amount of unutilized heat and traces of toxic radio nuclear into nearby water streams. Emissions from nuclear reactors and processing installations are also responsible for increasing the temperature of water bodies.
4. Hydro Electric Power—Generation of hydro-electric power also results in negative thermal loading of water bodies.
5. Domestic Sewage— Domestic sewage is often discharged into rivers, lakes, canals or streams without waste treatment. The municipal water sewage normally has a higher
temperature than receiving water. With the increase in temperature of the receiving water the dissolved oxygen content (DO) decreases and the demand of oxygen increases and anaerobic conditions occur.
Control of Thermal Pollution
1. Cooling Ponds—Cooling ponds or reservoirs constitute the simplest method of controlling thermal discharges. Heated e uents on the surface of water in cooling ponds maximize
dissipation of heat to the atmosphere and minimize the water area and volume. This is the simplest and cheapest method which cools the water to a considerable low temperature.
However, the technique alone is less desirable and ine cient in terms of air-water contact.
2. Cooling Towers—Using water from water sources for cooling purposes, with subsequent return to the water body after passing through the condenser is termed as cooling process.
In order to make the cooling process more effective, cooling towers are designed to control the temperature of water. In-fact, cooling towers are used to dissipate the recovered waste heat so as to eliminate the problems of thermal pollution.
3. Artificial Lake—Artificial lakes are man-made bodies of water which offer possible alternative to once through cooling. The heated effiuents may be discharged into the lake at
one end and the water for cooling purposes may be withdrawn from the other end. The heat is eventually dissipated through evaporation.
These lakes have to be rejuvenated continuously. A number of methods have been suggested and developed for converting the thermal effiuents from power plants into useful heat resources for maximing the benefits.
Nuclear Explosions are very rapid and based on a rough estimate, in an explosion about 50% of the energy goes to the blast, 33 % as heat and the rest 17%or so to radioactivity.
The radioactive dust that falls to the earth after atomic explosion is called radioactive fallout.The estimated percept dose to world population from fallout of past nuclear explosions is 10
microsievert per year. Radioactive substances are among the most toxic substances known. Radium is 25,000 times more lethal than arsenic. The cell, which is the fundamental unit of life, is the primary site of radiation damage. If too many cells are damaged, the symptoms show up in the growing tissues as in the case of loss of hair, ulceration of the mouth, the reddening and hemorrhaging of the skin and lowering of the blood count.
1.Somatic Effects—These are the direct results of action of radiation on the body cell and tissues. Uranium mineworkers, painters of radium dials and Radiologists suffer most. These
effects may be immediate or delayed. More evidence of degree and kind of damage from radiation came from studies of the Nagasaki and Hiroshima survivors. If one survives the phase of radiation illness in the 50 to 500 rad. range, the other illness one is likely to become a victim are-cardiovascular disorder, cataract, leukemia, sterility, premature ageing and shortenings of life span.
2. Genetic Effects—There is another more serious type of effect of ionizing radiations, known as genetic effect. This arises from the damage to the sex cells. If a sex cell is damaged and if
that sex cell is one of the pair that goes into the production of a fertilized ovum, it will give rise to an o spring with various kinds of major or minor physical defects.
Solid Waste Management:-
Wastes are chemical by-products of an industry, a factory or a chemical plant. They may result from household activity/a hospital or a research laboratory. Solid waste is the solid chemical
produced by any of these sources, which may be dangerous to human health and pollute the environment. Waste may be classi ed into two categories:
1. Toxic Waste (intrinsic characteristic)— Toxicity is the capacity of a substance to produce injury after entering the metabolic processes of the consumers (an animal, a plant or a human being). The changes may be pathogenic/mutagenic/tetragonic or carcinogenic.
2. Hazardous Waste (extrinsic characteristic)—Hazardous means the potential of a substance to pose threat to life. Hazardous wastes have the properties like toxicity, ignitibility,corrosiveness, reactivity, radioactivity or explosiveness. Hence, the term hazardous is brooder that includes “toxic" word in its spectrum.
Waste Management has become an important environmental and public health issue, which concerns many countries in the world; Waste Management can be done by the following four methods:
1. Waste Minimization (by minimization the quantity of waste)— Three major waste minimization techniques are:
(a) Process Modification— Industrial processes can be altered in such a way that the use of raw materials is optimized and the amount of waste is reduced.
(b) Waste Concentration—The large amount of waste can be minimized by concentration processes like evaporation, precipitation or decantation technique. Volume of waste can be minimized by this technique.
(c) Waste Segregation—Segregating the waste streams from non-hazardous streams can minimize the volume of waste.
2. Treatment of Waste— The aim of treatment of waste is to modify the physical and /or chemical properties of the wastes so that they are rendered harmless. Selection of treatment process depends upon nature of waste, economic and energy consideration,
a) Biological treatment— Solid waste minimization is done by biological treatment of the waste before disposal. This treatment include three processes
• Conditioning— In this process, the solid is exposed to atmosphere for a stipulated period until the desired constancy is reached.
• Digestion—Waste is treated with bacteria in this process. The bacteria break down the long chain compounds into simpler ones.
• Composting—In this process the waste is converted into the usable stable material.
3. Recycling of Wastes—Many substances in the solid wastes (glass, wood bre from the paper products and metals) are variable and can be utilized after recycling the waste. The two processes are often used to recycle the waste.
(a) Reuse of the waste
(b) Recycling of the waste
4. Disposal of waste material— There are four different ways of disposal of solid waste material:
(a) Land Fill Disposal
(b) Incineration (burning of waste products)
(c) Dumping at sea (for prevention of ground water pollution, disposal of waste is controlled by international legislation and by national legislation).
(d) Underground disposal (underground disposal may provide an environmentally and economically viable option for radioactive wastes).
Municipal Sewage:-
Municipal solid waste consists of household waste, construction and demolition debris, sanitation residue, and waste from streets. This garbage is generated mainly from residential and commercial
complexes. With rising urbanization and change in lifestyle and food habits, the amount of municipal solid waste has been increasing rapidly and its composition changing. In 1947 cities
and towns in India generated an estimated 6 million tonnes of solid waste, in 1997 it was about 48 million tonnes. More than 25% of the municipal solid waste is not collected at all; 70% of the
Indian cities lack adequate capacity to transport it and there are no sanitary land lls to dispose of the waste. The existing land fills are neither well equipped or well managed and are not lined
properly to protect against contamination of soil and groundwater.
UGC NET Paper1 Notes PDF
₹299 Atmosphere
Atmosphere creates a protective shell over the earth. The atmosphere, which is a gaseous cover,Protects the earth from cosmic radiations and provides life sustaining Oxygen, the macro nutrient.
Nitrogen and Carbon dioxide needed for photosynthesis.
Structure of the Atmosphere
The atmosphere is broadly divided into four major zones.
1. Troposphere
2. Stratosphere
3. Mesosphere
4. Thermo sphere
1. Troposphere—The troposphere layer is near to the ground level of earth. The composition of gases is nearly same throughout the layer. Most of the naughty activity of weather happens in this layer. The transition layer between troposphere and stratosphere
is called Tropopause.
2. Stratosphere—The layer above the troposphere is called stratosphere where temperature increases with height. These layer is also known as “Ozone layer” because ozone gas is found in higher densities here. Stratosphere is hot layer because ozone absorbs radiant energy from the sun. The transition between the stratosphere and mesosphere is called Stratopause.
3. Mesosphere—Layer above the stratosphere is called mesosphere where temperature decreases with height. This layer is very cold. The transition layer between mesosphere and thermosphere is called Mesopause.
4. Thermosphere—Thermosphere is the layer above the mesosphere. In this layer, temperature increases with height. Here density of air is less and eventually we enter into space.
Lithosphere
The crust of the earth containing rock, soil and sediments is called lithosphere. The soil is composed of inorganic and organic matter and water. The main minerals in lithosphere are composed of the elements silicon, calcium, potassium, aluminum, iron, manganese etc. Theorganic constituents are mainly organic compounds of N, P and S.
Hydrosphere
Hydrosphere layer comprised of 3/4th portion on earth. It mainly contains both surface and groundwater. Major constituents of hydrosphere are oceans, lakes, streams, rivers, water vapor
and glacier. The distribution of water among these resources is as
water source Volume in %
oceans and seas 96-97 %
glaciers and polar ice 2-3 %
Freshwater < 1%
The most common components of hydrosphere
Biosphere
Biosphere encircles the earth’s surface where all the living things exist. This layer extend from 10,000 m below sea level to 6000 m above sea level. The biosphere covers parts of other segments
of the environment viz. Lithosphere, Hydrosphere and Atmosphere. Biosphere is a biological environment where living organism interacting with physical environment for example soil,
water and air.
Ecosystem-
Ecosystem is a complex set of relationship among the living resources, habitats, and residents of an area. Ecosystem consists of plants, animals, birds, water, soil and people. A healthy ecosystem
is called sustainable. This means all the elements in the system is in balance and are capable of reproducing themselves.
Ecology is the study of interrelationship among plants and animals and their interactions with the physical environment.
Ecology Categories-
1. Autoecology— it is the study of an individual species. For example, behavior, adaptation and interaction of a particular species in its own environment. Autoecology is also known as species ecology.
2. Synecology— it is the study of communities and their interaction with the environment.Synecology is also known as ecology of communities.Examples of large eco systems are rain forests, deserts, salt marshes, coral reefs, lakes and ponds, open ocean, grass lands etc.
Types of Ecosystem
The main two kinds of ecosystem are Terrestrial and Aquatic.
Terrestrial Ecosystem
One can find terrestrial ecosystem anywhere except heavily saturated places. It is further classified
into following categories-
1. Forest Ecosystem
• Tropical Evergreen Forest
• Tropical Deciduous Forest
• Temperature Evergreen Forest
• Temperature Deciduous Forest
• Taiga
2. Desert Ecosystem
3. Grassland Ecosystem
4. Mountain Ecosystem
1. Forest Ecosystem— They are the ecosystems in which an abundance of flora, or plants, is seen so they have a big number of organisms which live in relatively small space. Therefore,
in forest ecosystems the density of living organisms is quite high. A small change in this
ecosystem could affect the whole balance, effectively bringing down the whole ecosystem.
(a) Tropical Evergreen Forest: Tropical evergreen forest are areas where mean rainfall of 80 for every 400 inches annually happen. Here forest is dense and it comprises of tall trees of different heights.
(b) Tropical Deciduous Forest: Shrubs and Dense bushes rule along with a broad selection of trees. This type of forest is found in quite a few parts of the world while a large variety of fauna and flora are found there.
(c) Temperate Evergreen Forest: Those have quite a few number of trees as mosses and ferns make up for them. Trees have developed spiked leaves in order to minimize transpiration.
(d) Temperate Deciduous Forest: The forest is located in the moist temperate places that have sufficient rainfall. Summers and winters are clearly defined and the trees shed the leaves during the winter months.
(e) Taiga: It is situated just before the arctic regions, the taiga is de ned by evergreen conifers. As the temperature is below zero for almost half a year, the remainder of the months, it buzzes with migratory birds and insects.
2. Desert Ecosystem— Desert ecosystem is located in the regions where annual rainfall is very less. The area of desert ecosystem is 17% of the total land area on our planet. Due to the extremely high temperature, low water availability and intense sunlight, fauna and
ora are scarce and poorly developed. The vegetation is mainly shrubs, bushes, few grasses and rare trees.
3. Grassland Ecosystem— Grassland ecosystem is located in both the tropical and temperature region of the world. It has variety of grasses, harps, insects depending on climatic conditions and temperature. The grasslands are degraded day by day because of overgrazing.
The two main kinds of grasslands ecosystems are:
(a) Savanna— The tropical grasslands are dry seasonally and have few individual trees.
They support a large number of predators and grazers.
(b) Prairies— It is temperate grassland, completely devoid of large shrubs and trees.Prairies could be categorized as mixed grass, tall grass and short grass prairies.
4. Mountain Ecosystem— Mountain land provides a scattered and diverse array of habitats where a large number of animals and plants can be found. At the higher altitudes, the harsh environmental conditions normally prevail, and only the treeless alpine vegetation can survive. The animals that live there have thick fur coats for prevention from cold and hibernation in the winter months. Lower slopes are commonly covered with coniferous forests.
Natural environment is of crucial importance for social and economic life. We use the living world as
1. A resource for food supply
2. An energy source
3. A source for recreation
4. A major source of medicines
5. Natural resources for industrial products.Human impact the environment in several ways. Common effects are-
Decreased water quality, Increased pollution and greenhouse gas emissions, depletion of natural resources and contribution to global climate change.
Some of these are the direct result of human activities,
whereas others are secondary effects that are part of a series of actions and reactions.
Agriculture
Modern agriculture is responsible for the loss of much wildlife and their habitats , through reduction and fragmentation of habitats and wildlife populations. The drainage of wetlands, the de structure hedgerows and the intensive use of fertilizers and pesticides can all pose a threat to wildlife.
Following are the basic causes of agriculture pollution.
1. Pesticides and Fertilizers— Modern day pesticides & fertilizers have to deal with the local pests that have existed for hundreds of years along with the new invasive species. And so,
they are laden with chemicals that are not found in nature.
Once they has been sprayed, it does not disappear completely. Some of it mixes with the water and seeps into the ground. The rest of is absorbed by the plant itself. As a result, the local streams that are supplied water from the ground become contaminated, as do the
animals that eat these crops and plants.
2. Contaminated Water—Contaminated water used for irrigation is one further source of pollution. Much of the water we use comes from ground water reservoirs, canals and through the rains. While plenty of it is clean and pure water, other sources are polluted
with organic compounds and heavy metals. This happens due to the disposal of industrial and agricultural waste in local bodies of water.
As a result, the crops are exposed to water which has small amounts of mercury, arsenic,lead and cadmium dissolved in it. The process of agricultural pollution becomes harder to
fight when such water poisons the livestock and causes crop failure.
3. Soil Erosion and Sedimentation— Further problems are caused by soil erosion and sedimentation. Soil is comprised of many layers and it is only the topmost layer that can
support farming or grazing. Due to ine cient farming practices, this soil is left open for erosion and leads to declining fertility each year. Whether eroded by water or wind, all this
soil has to be deposited somewhere or the other.
Land Pollution:-
Land pollution means degradation or destruction of earth’s surface and soil,directly or indirectly as a result of human activities. Anthropogenic activities are conducted citing development, and the same affects the land drastically.
Below are the sources of land pollution:
1. Deforestation and Soil Erosion— Deforestation carried out to create dry lands is one of the major concerns. Land that is once converted into a dry or barren land, can never be made fertile again, whatever the magnitude of measures to redeem it are.
Land conversion,meaning the alteration or modification of the original properties of the land to make it use-worthy for a specific purpose is another major cause.
2. Agricultural Activities— With growing human population, demand for food has increased considerably. Farmers often use highly toxic fertilizers and pesticides to get rid off insects,
fungi and bacteria from their crops. However with the overuse of these chemicals, they result in contamination and poisoning of soil.
3. Mining Activities— During extraction and mining activities, several land spaces are created beneath the surface. We constant hear about land caving in; this is nothing but nature’s way of filling the spaces left out after mining or extraction activity.
4. Overcrowded Land Fills—Each household produces tonnes of garbage each year. Garbage like aluminum, plastic, paper, cloth, wood is collected and sent to the local recycling unit.
Items that can not be recycled become a part of the land fills that hampers the beauty of the city and cause land pollution.
5. Industrialization— Due to increase in demand for food, shelter and house, more goods are produced. This resulted in creation of more waste that needs to be disposed of. To meet the demand of the growing population, more industries were developed which led
to deforestation. Research and development paved the way for modern fertilizers and chemicals that were highly toxic and led to soil contamination.
6. Construction Activities— Due to urbanization, large amount of construction activities are taking place which has resulted in large waste articles like wood, metal, bricks, plasticthat can be seen by naked eyes outside any building or office which is under construction.
Waterlogging and its Effect
Water logging refers to the saturation of soil with water. Soil may be regarded as waterlogged when the water table of the groundwater is too high to conveniently permit an anticipated activity,like agriculture. In agriculture, various crops need air (speci cally, oxygen) to a greater or lesser depth in the soil. Water logging of the soil stops air getting in.
1. Depletion of oxygen in root zone and increase of CO2 due to water logging. An aerobic condition adversely affects micro-organisms while harmful organisms proliferate and restrict the plant growth.
2. Physical or chemical and biological activities in the soil are disturbed due to low temp.as a result of water logging. Thus pest and diseases infestation problem arises.
3. Water logging makes field operations difficult on impossible.
4. The adverse effects of water logging get accelerated when the capillary water brings salts from lower horizon of soil or they are present in the ground water used for irrigation.
5. Water logging adversely affect the soil water plant relationship there by creating ecological imbalance.
6. Secondary salinization caused by the salts which are brought up from lower horizon strict the uptake of moisture and nutrients in the plant roots and create toxic effect in the root system.
7. Due to excess soluble salts the physical condition of soil deteriorates. Highly deteriorated alkali soils have very low in filtration rates. Most rainfall goes as runo , causing crop
damages in adjoining area.
8. Crops yields reduced and some times crop failure due to inadequate uptake of moisture and nutrients and due to the injurious effect of salts or deteriorated soil condition.
9. Fodders grown in slat-affected soils may contain high molybdenum in or selenium and low amount of zinc. The nutritional imbalance may cause disease in live stock.
Organic Farming:-
Organic Farming system in India is not new and is being followed from ancient time. It is a method of farming system which primarily aimed at cultivating the land and raising crops in such a way,as to keep the soil alive and in good health by use of organic wastes (crop, animal and farm wastes,aquatic wastes) and other biological materials along with beneficial microbes (biofertilizers) to release nutrients to crops for increased sustainable production in an eco friendly pollution free.
The key characteristics of organic farming include.
1. Protecting the long term fertility of soils by maintaining organic matter levels, encouraging soil biological activity, and careful mechanical intervention.
2. Providing crop nutrients indirectly using relatively insoluble nutrient sources which are made available to the plant by the action of soil micro-organisms.
3. Nitrogen self-sufficiency through the use of legumes and biological nitrogen xation,as well as effective recycling of organic materials including crop residues and livestock manures.
4. Weed, disease and pest control relying primarily on crop rotations, natural predators,diversity, organic manuring, resistant varieties and limited (preferably minimal) thermal,biological and chemical intervention.
5. The extensive management of livestock, paying full regard to their evolutionary adaptations, behavioural needs and animal welfare issues with respect to nutrition, housing,health, breeding and rearing.
6. Careful attention to the impact of the farming system on the wider environment and the conservation of wildlife and natural habitats.
ENERGY:_- Energy is the ability to do work. The word ‘work’ means transferring energy from one place to another. energy is neither destroyed nor created. It can only be changed.
Resources of Energy- Renewable
Non -Renewable
Energy is the ability to do work. All forms of energy are stored in di erent ways. Energy sources
we use every day. These sources are divided into 2 groups.
Non -Renewable Resource-
A nonrenewable resource is a natural resource that cannot be re-made or re-grown at a scale comparable to its consumption. Coal, petroleum, and natural gas . These are called fossil fuels.Nuclear
ssion uses uranium to create energy.
Nuclear energy is a Non- Renewable resource because once
the uranium is used, it is gone.
Example -
1. Oil
2. Coal
3. Natural gas
4. Nuclear
Renewable Resource
Renewable resources are natural resources that can be replenished in a short period of time.
Example
1. Solar
2. Geothermal
3. Wind
4. Biomass
5. Water
6. Wave and Tidal Power
Fossil Fuels
Fossils fuels gives 85% of the world’s commercial energy. Fossil fuels is highly combustible substances formed from remains of organisms from past geologic ages. Fossil fuels we burn today
were formed from the tissues of organisms that lived 100-500 million years ago. Fossil fuels are
produced only when organic materials is broken down in an anaerobic environment , one that has
little or no oxygen. Bottoms of deep lakes, swamps, and shallow seas organic matter is eventually
converted into crude oil, natural gas, or coal. It is said that we are using a million years worth of
geological production every dayCoal energy
Coal is organic matter (woody plant material) that was compressed under very high pressure to
form dense, solid carbon structures.
Subsurface mining
In this case underground deposits are reached by digging networks of tunnels deep underground Strip mining.
Here heavy machinery removes huge amounts of earth to expose and extract the coal removalMountaintop
in some cases, entire mountaintops are cut off to obtain the coal.
Formation of coal as follows
1. Peat is compressed to form lignite , which is also known as brown coal
2. Lignite is compressed and volatile compounds are lost to form bituminous coal –soft coal
3. Bituminous coal is further compressed and heated to form anthracite– hard coal
Solar Energy
It is the Ultimate Renewable Resource. It originates with the thermonuclear fusion reactions occurring in the sun. The surface receives about 47% of the total solar energy that reaches the
Earth. Only this amount is usable.
Advantages of solar energy-
1. All chemical and radioactive polluting byproducts of the thermonuclear reactions remain behind on the sun, while only pure radiant energy reaches the Earth.
2. Energy reaching the earth is incredible. By one calculation, 30 days of sunshine striking the Earth have the energy equivalent of the total of all the planet’s fossil fuels, both used and unused
Disadvantages of Solar Energy
1. Sun does not shine consistently.
2. Solar energy is a diffuse source. To harness it, we must concentrate it into an amount andform that we can use, such as heat and electricity.
Why we should use Solar Energy-
1.Argument that sun provides power only during the day is countered
by the fact that 70% of energy demand is during daytime hours. At night, traditional methods can be used to generate the electricity.
2. Our goal is to decrease our dependence on fossil fuels.
3. Currently, 75% of our electrical power is generated by coal-burning and nuclear power plants.
4. It mitigates the e ects of acid rain, carbon dioxide, and other impacts of burning coal and counters risks associated with nuclear energy.
5. It is pollution free, indefinitely sustainable.
Wind Energy:-
The earth’s winds are caused by pressure differences across the earth’s surface due to uneven heating. An estimated 1% to 3% of energy from the Sun that hits the earth is converted into wind
energy. The principle of wind is simple. The poles receive less energy than the equator does from the sun. Also land heats up and cools down more quickly than the seas. This difference between
the seas and the land causes a global atmospheric convection system.
Local Winds:
During the day the air over the land is heated more than the air over the sea. Opposite during the night.
Day pattern:Wind blows from sea to land
Night patt ern:Wind blows from land to sea
Ocean Thermal Energy
Energy is available from the ocean by
1. Tapping ocean currents
2. Using the ocean as a heat engine
3. Tidal energy
4. Wave energy
ocean energy is replenished by the sun and through tidal influences of the moon’s and sun’s gravitational forces. Near-surface winds induce wave action and cause wind-blown currents at about 3% of the wind speed. Tides cause strong currents into and out of coastal basins and rivers.
Ocean surface heating by some 70% of the incoming sunlight adds to the surface water thermal energy, causing expansion and ow. Wind energy is stronger over the ocean due to less drag,
although technically, only sea breezes are from ocean energy.
1. There can be a 20◦ difference between ocean surface temps and the temp at 1000m
2. The surface acts as the heat source, the deeper cold water acts as a heat sink.
3. Temperature differences are very steady.
4. Florida, Puerto Rico, Hawaii and other pacific islands are well suited to take advantage of this idea, called OTEC (Ocean Thermal Energy Conversion)
Wave Energy:-
Wave power is the transport of energy by ocean surface waves, and the capture of that energy to do useful work —for example, electricity generation, water desalination, or the pumping of water
(into reservoirs). A machine able to exploit wave power is generally known as a wave energy converter (WEC).
Important points-
1.1799: First patent of a device designed to use ocean waves to generate power
2. 1910: First oscillating water column was built by Bochaux-Praceique to power his house
3. 1940s: Yoshio Masuda experimented with many concepts of wave power
4. 2004: Wave power was delivered to an electrical grid for the rst time
Tidal Energy:-
Most of the energy sources we have been discussing derived their energy from the sun originally.
Tides are driven by gravity. Gravity is a force that exists between any two objects based upon their mass and the distance between them
Fg = GmM/R2
where M and m are the masses of the two objects, R is the distance between them and G is the
gravitational constant
Hydropower:-
Electricity produced from the water is called the Hydropower or hydro-electric power. The falling water turns the water wheel or the turbine and electricity is generated. It is the most convenient
and versatile form of energy. It plays a key role in agriculture and industrial development and nation’s growth and productivity can be analyzed through the quantity of its energy consumption.
Since rst ve year plan, India is given much emphasis on generation of hydro-electric power from major hydro and mini hydel projects.
The Major Hydro Electricity Projects in India
Sivsamundra project of the river the Can very in Karnataka was the first major hydro-electric project in Asia. It was constructed in 1902.
Some of the important major hydropower projects are discussed below.
1. Bhakra Nangal Project— The Bhakra Nangal project, on the river the Sutlej, with its four power stations at Nangal, Bhakra, Ganguwal and Kotla is an important hydro power project. It has an installed capacity of 1.2 million KW. It supplies electricity to Punjab, Haryana and Delhi.
2. Damodar Valley Project— The Damodar valley project, with its three hydel power stations at Tilaiya, Matron and Panchet is built on the river the " Damodar. It has an installed capacity of 104 mw (megawaits) electricity. It supplies power to Bihar and West Bengal.
3. Hirakud Dam Project—The major hydro-Electricity power project in Orissa is the Hirakud Dam Project on the river the Mahanadi. Its capacity of generating power is 270.2MW. The Rourkela Steel Plant mainly gets power supply from it.
4. Riband Project— It is essentially a hydroelectric project. It has an installed capacity of 300 MW. On the boarders of Uttar Pradesh and Madhya Pradesh water is stored in form of a large lake and power is generated.
5. Chambal Valley Project—On the river the Chambal, two power houses are constructed, one at Gandhi Sagar Dam in Madhya Pradesh and the other one at Kota in Rajasthan. The total installed capacity from both the power houses is 180 MW.
6. Koyana Hydro Electric Project—It is one of the largest projects in Maharashtra. The water of the Koyana, a tributory of the Krishna is utilized for power generation. The total capacity installed is 540 MW. It supplies electricity mainly to Bombay-Poona industrial belt.
7. Tungabhadra Project—This is a joint collaboration of Andhra Pradesh and Karnataka.The power house is built on the river the Tungabhadra.These are few hydroelectric projects.
8. Gandak hydroelectric Project -This project is on the river
the Gandak, and Parambikulam Aliyar on the river the Periyar.
Biomass:-
Biomass is a Renewable Energy source because the energy it contains comes from the sun.Through the process of photosynthesis, chlorophyll in plants captures the sun’s energy by
converting carbon dioxide from the air and water from the ground into carbohydrates, complex compounds composed of carbon, hydrogen, and oxygen. When these carbohydrates are burned,
they turn back into carbon dioxide and water and release the sun’s energy they contain. In this way, biomass functions as a sort of natural battery for storing solar energy. As long as biomass is
produced sustainable—with only as much used as is grown—the battery will last inde nitely.
From the time of Prometheus to the present, the most common way to capture the energy
from biomass was to burn it, to make heat, steam, and electricity. But advances in recent years
have shown that there are more efficient and cleaner ways to use biomass. It can be converted
into liquid fuels, for example, or cooked in a process called “gasi cation” to produce combustible
gases. And certain crops such as switch grass and willow trees are especially suited as “energy
crops,” plants grown speci cally for energy generation.
Nuclear Fuels
Nuclear energy is energy that is generated through the use of Uranium, a natural metal that
is mined all over the world. Nuclear energy is created through complex processes in nuclear
power stations, and the rst nuclear power station was established in 1956 in Cumbria, England.
Today, many military operations and vessels use nuclear power plants and nuclear energy for
their energy source, and nuclear energy is used in many other capabilities such that it provides
16% of the Earth’s energy requirements.
Environmental Pollution-
Man is one of the species who inhabit the earth.he is the only one who has interfered with various natural processes for use of both biological & physical resources to meet his multiple demands,man
has polluted all the three realms of the earth lithosphere,hydrosphere & atmosphere.it is essential for us to know about environment & its pollution.
Air-Pollution-
Air pollution is the addition of gases, chemicals, and particle matter into the atmosphere. Air pollution primarily comes from burning fossil fuels such as natural gas, petroleum, and coal.
Types of Air Pollution
1. Primary Pollutants: are the one which consist of materials such as dust, gases, liquids and other solid material around that enter the atmosphere through natural and human made activities. The main pollutants are carbon monoxide, sulphuroxide, nitrogen oxides.
2. Secondary Pollutant: consist of primary pollutants which reacted
with each other and makes our air polluted. In megacities, the emissions from road car and industries combine themselves and makes photochemical smoge with the help of light energy from the sun. Also the indoor pollutants have been identified some of the more common indoor air pollutants include smoke from cigarettes and cooking, asbestos etc. At high concentrations, these pollutants can cause dizziness. Headaches, coughing. Sneezing.
Nausea, burning eyes, chronic fatigue like symptoms.
Some indoor pollutants, like asbestos and smoke, can cause disease and premature death
Controlling Air Pollution
1. Rather than controlling air pollution, we should prevent the pollution
2. We must use clean wheels in cars and other auto mobiles
3. We have to use non-pollutant energy like solar energy, wind power and hydro prior
4. We have to control the population growth of the world
5. Encourage mass transit and less polluting forms of transportation (e. g. switch from air
travel to rail travel).
Water Pollution:-
Water pollution occurs when harmful substances are released into the water in large quantities which cause damage to people, wildlife, or habitat or indirectly into water bodies .Water pollution
affects plants and organisms living in the bodies of water; and, in almost all cases the effect is
damaging either to individual species and also to the biological communities.
Water pollution sources
Chemical & other contaminants are basic sources of water pollution.Contaminants may include
organic and inorganic substances.
Effect of Water Pollution
1. Water pollution is a major problem in the global context. It has been suggested that it is
the leading worldwide cause of deaths and diseases, and that it accounts for the deaths of
more than 14,000 people daily.
2. An estimated 700 million Indians have no access to a proper toilet, and 1,000 Indian children
die of diarrhea sickness every day.
3. Some 90% of China’s cities suffer from some degree of water pollution, and nearly 500
million people lack access to safe drinking water.
4. In addition to the acute problems of water pollution in developing countries, industrialized
countries continue to struggle with pollution problems as well.
Interactions between groundwater and surface water are complex. Consequently, groundwater
pollution is not as easily classiffied as surface water pollution.
Inorganic water pollutants include:
1. Acidity caused by industrial discharges (especially sulphur dioxide from power plants)
2. Ammonia from food processing waste
3. Chemical waste as industrial by-products
4. Fertilizers containing nutrients–nitrates and phosphates,which are found in storm water
run off from agriculture, as well as commercial and residential use.
5. Heavy metals from motor vehicles (via urban storm water runo ) and acid mine drainage
6. Silt (sediment) in runo from construction sites, logging, slash and burn practices or land
clearing sites
7. Macroscopic pollution—large visible items polluting the water, may be termed “ oatables"
in an urban storm water context, or marine debris when found on the open seas, and can
include such items as:
8. Trash: (e.g. paper, plastic, or food waste) discarded by people on the ground, and that are
washed by rainfall into storm drains and eventually discharged into surface waters.
9. Nurdles: small ubiquitous waterborne plastic pellets.
10. Shipwrecks: large derelict ships.
Purification of water
Purification of water involves physical, biological and chemical processes such as:
1. Filtration
2. Sedimentation
3. Chlorination
4. Slow sand Filters
5. Activated Sludge
6. Flocculation
• Filtration:Filtration is a mechanical or physical operation which is used for the separation
of solids from uids (liquids or gases) by interposing a medium through which only the
uid can pass.
• Sedimentation: Sedimentation is the tendency for particles in suspension or molecules in
solution to settle out of the fluid in which they are entrained, and come to rest against a
wall.
• Chlorination -the process of adding the element chlorine to water as a
method of water puri cation to make it t for human consumption as drinking water. Water
which has been treated with chlorine is e ective in preventing the spread of water born
disease.
• Slow sand Filters- are used in water puri cation for treating raw water
to produce a potable product. They are typically 1 to 2 metres deep, can be rectangular or
cylindrical in cross section and are used primarily to treat surface water.
• Activated Sludge: Activated sludge is a process dealing with the treatment of sewage and
industrial wastewaters and developed around 1912-1914.Atmospheric air or pure oxygen is
introduced to a mixture of primary treated or screened sewage (or industrial wastewater)
combined with organisms to develop a biological oc which reduces the organic content of
the sewage
• Flocculation: is, in the field of chemistry, a process where colloids come out
of suspension in the form of oc or akes. The action differs from precipitation in that,
prior to occulation, colloids are merely suspended in a liquid and not actually dissolved in
a solution.
Farming solution : Choosing organic options can help to reduce the amount of water
pollution. These items are grown without the use of chemicals. Those chemicals, when
used, enter the water cycle. Organic products don’t introduce those chemicals to the
water cycle.
Soil Pollution-
The introduction of substances, biological organisms, or energy into the soil, resulting in a change
of the soil quality, which is likely to aff ect the normal use of the soil or endangering public health
and the living environment.
Soil contaminants are spilled onto the surface through many different activities. Most of these
are the result of accidents involving the vehicles that are transporting waste material from site of
origin to a disposal site.
Others involve accidents involving vehicles (automobiles, trucks and airplanes) not transport-
ing wastes, but carrying materials, including fuel, that when spilled contaminate the soil.
Marine Pollution
Marine pollution occurs when harmful, or potentially harmful, e ects result from the entry into
the ocean of chemicals, particles, industrial, agricultural and residential waste, noise, or the spread
of invasive organisms. Most sources of marine pollution are land based. The pollution often
comes from nonpoint sources such as agricultural runo , wind-blown debris and dust. Nutrient
pollution, a form of water pollution, refers to contamination by excessive inputs of nutrients. It is
a primary cause of eutrophication of surface waters, in which excess nutrients, usually nitrogen
or phosphorus, stimulate algae growth.
There are ve main kinds of marine pollution, namely:
1. Pollution from land-based sources, such as rivers, estuaries, pipelines and outfall structures;
2. Pollution from exploitation of the mineral resources of the sea-bed;
3. Pollution from ships, i.e. the disposal of wastes or other matter incidental to or derived
from the normal operations of ships;
4. Pollution by dumping, i.e. the deliberate disposal of wastes or other matter from ships,
aircraft, platforms or other man-made structures at sea;
5. Pollution through the atmosphere.
Noise Pollution:-
Noise is “sound without value” or “any noise that is undesired by the recipient”.Thus, the kind of environmental impact of noise pollution is slightly di erent from other kinds of pollution.
Generally, there is much more noise in the urban areas because of larger concentration of
population as well as industrial and other activities like transportation vehicular movements, etc.
Non-industrial sources of noise can come from public address systems for religious or political
propaganda, recreation, hawkers or other street noise. Noise can also arise from the natural
sources like thunder.
Noise as a potent menace can be evaluated in terms of a ‘noise level’ scale, or in decibels (dB).
However, the health hazard is a matter of perceived noise level decibels (pNdB), which according
to the W.H.O.’s prescribed optimum noise level as 45 dB by day and 35 by night; and anything
above 80 dB is hazardous.
noise pollution can be minimized
only through rigorous law and conscious e orts of the law enforcement department.
• Sources of Noise Pollution— The indoor sources of Noise Pollution are loudly played
music stereos, radio, televisions, grinding machines, etc. The outdoor sources of Noise
Pollution commonly referred to as environmental noise comes from airplane, machines,
trains, vehicles, industries, etc.
• Effect on Human Health— It may a ect the mind, health and behaviour. It may cause
physically discomfort and temporary or permanent damage to hearing. It causes headache
and irritability. Loud speakers not only disturb the student in their studies but also the
peace of locality. It may cause deafness, stress and high-blood pressure.
• Effect on Animal Health— Animals suffer badly due to noise pollution. At times, it can
also lead to death. Noise has impact on the living pattern of the animals and it may push
the rare species to extinction. Like humans, they also suffer from temporary or permanent
disability of hearing.
Thermal pollution:
An increase in the optimum water temperature by industrial process (steel factories, electricpower houses and atomic power plants) may be called as “Thermal Pollution." Many industries
generate their own power and use water to cool their generator.
The various causes of thermal pollution are as follows
1. Coal- red Power Plants—Some thermal power plants use coal as fuel. Coal- red power plants constitute the major source of the thermal pollution.
2. Industrial Effiluents—Industries generating electricity require large amount of Cooling
water for heat removal. Other industries like textile, paper, and pulp and sugar industry also release heat in water, but to a lesser extent.
Nuclear Power Plants—Nuclear power plants emit a large amount of unutilized heat and traces of toxic radio nuclear into nearby water streams. Emissions from nuclear reactors and processing installations are also responsible for increasing the temperature of water bodies.
4. Hydro Electric Power—Generation of hydro-electric power also results in negative thermal loading of water bodies.
5. Domestic Sewage— Domestic sewage is often discharged into rivers, lakes, canals or streams without waste treatment. The municipal water sewage normally has a higher
temperature than receiving water. With the increase in temperature of the receiving water the dissolved oxygen content (DO) decreases and the demand of oxygen increases and anaerobic conditions occur.
Control of Thermal Pollution
1. Cooling Ponds—Cooling ponds or reservoirs constitute the simplest method of controlling thermal discharges. Heated e uents on the surface of water in cooling ponds maximize
dissipation of heat to the atmosphere and minimize the water area and volume. This is the simplest and cheapest method which cools the water to a considerable low temperature.
However, the technique alone is less desirable and ine cient in terms of air-water contact.
2. Cooling Towers—Using water from water sources for cooling purposes, with subsequent return to the water body after passing through the condenser is termed as cooling process.
In order to make the cooling process more effective, cooling towers are designed to control the temperature of water. In-fact, cooling towers are used to dissipate the recovered waste heat so as to eliminate the problems of thermal pollution.
3. Artificial Lake—Artificial lakes are man-made bodies of water which offer possible alternative to once through cooling. The heated effiuents may be discharged into the lake at
one end and the water for cooling purposes may be withdrawn from the other end. The heat is eventually dissipated through evaporation.
These lakes have to be rejuvenated continuously. A number of methods have been suggested and developed for converting the thermal effiuents from power plants into useful heat resources for maximing the benefits.
Nuclear Explosions are very rapid and based on a rough estimate, in an explosion about 50% of the energy goes to the blast, 33 % as heat and the rest 17%or so to radioactivity.
The radioactive dust that falls to the earth after atomic explosion is called radioactive fallout.The estimated percept dose to world population from fallout of past nuclear explosions is 10
microsievert per year. Radioactive substances are among the most toxic substances known. Radium is 25,000 times more lethal than arsenic. The cell, which is the fundamental unit of life, is the primary site of radiation damage. If too many cells are damaged, the symptoms show up in the growing tissues as in the case of loss of hair, ulceration of the mouth, the reddening and hemorrhaging of the skin and lowering of the blood count.
1.Somatic Effects—These are the direct results of action of radiation on the body cell and tissues. Uranium mineworkers, painters of radium dials and Radiologists suffer most. These
effects may be immediate or delayed. More evidence of degree and kind of damage from radiation came from studies of the Nagasaki and Hiroshima survivors. If one survives the phase of radiation illness in the 50 to 500 rad. range, the other illness one is likely to become a victim are-cardiovascular disorder, cataract, leukemia, sterility, premature ageing and shortenings of life span.
2. Genetic Effects—There is another more serious type of effect of ionizing radiations, known as genetic effect. This arises from the damage to the sex cells. If a sex cell is damaged and if
that sex cell is one of the pair that goes into the production of a fertilized ovum, it will give rise to an o spring with various kinds of major or minor physical defects.
Solid Waste Management:-
Wastes are chemical by-products of an industry, a factory or a chemical plant. They may result from household activity/a hospital or a research laboratory. Solid waste is the solid chemical
produced by any of these sources, which may be dangerous to human health and pollute the environment. Waste may be classi ed into two categories:
1. Toxic Waste (intrinsic characteristic)— Toxicity is the capacity of a substance to produce injury after entering the metabolic processes of the consumers (an animal, a plant or a human being). The changes may be pathogenic/mutagenic/tetragonic or carcinogenic.
2. Hazardous Waste (extrinsic characteristic)—Hazardous means the potential of a substance to pose threat to life. Hazardous wastes have the properties like toxicity, ignitibility,corrosiveness, reactivity, radioactivity or explosiveness. Hence, the term hazardous is brooder that includes “toxic" word in its spectrum.
Waste Management has become an important environmental and public health issue, which concerns many countries in the world; Waste Management can be done by the following four methods:
1. Waste Minimization (by minimization the quantity of waste)— Three major waste minimization techniques are:
(a) Process Modification— Industrial processes can be altered in such a way that the use of raw materials is optimized and the amount of waste is reduced.
(b) Waste Concentration—The large amount of waste can be minimized by concentration processes like evaporation, precipitation or decantation technique. Volume of waste can be minimized by this technique.
(c) Waste Segregation—Segregating the waste streams from non-hazardous streams can minimize the volume of waste.
2. Treatment of Waste— The aim of treatment of waste is to modify the physical and /or chemical properties of the wastes so that they are rendered harmless. Selection of treatment process depends upon nature of waste, economic and energy consideration,
a) Biological treatment— Solid waste minimization is done by biological treatment of the waste before disposal. This treatment include three processes
• Conditioning— In this process, the solid is exposed to atmosphere for a stipulated period until the desired constancy is reached.
• Digestion—Waste is treated with bacteria in this process. The bacteria break down the long chain compounds into simpler ones.
• Composting—In this process the waste is converted into the usable stable material.
3. Recycling of Wastes—Many substances in the solid wastes (glass, wood bre from the paper products and metals) are variable and can be utilized after recycling the waste. The two processes are often used to recycle the waste.
(a) Reuse of the waste
(b) Recycling of the waste
4. Disposal of waste material— There are four different ways of disposal of solid waste material:
(a) Land Fill Disposal
(b) Incineration (burning of waste products)
(c) Dumping at sea (for prevention of ground water pollution, disposal of waste is controlled by international legislation and by national legislation).
(d) Underground disposal (underground disposal may provide an environmentally and economically viable option for radioactive wastes).
Municipal Sewage:-
Municipal solid waste consists of household waste, construction and demolition debris, sanitation residue, and waste from streets. This garbage is generated mainly from residential and commercial
complexes. With rising urbanization and change in lifestyle and food habits, the amount of municipal solid waste has been increasing rapidly and its composition changing. In 1947 cities
and towns in India generated an estimated 6 million tonnes of solid waste, in 1997 it was about 48 million tonnes. More than 25% of the municipal solid waste is not collected at all; 70% of the
Indian cities lack adequate capacity to transport it and there are no sanitary land lls to dispose of the waste. The existing land fills are neither well equipped or well managed and are not lined
properly to protect against contamination of soil and groundwater.
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