Ge6351 Cse Eee It

8/17/2019 Ge6351 Cse Eee It

1/75

www.vidyarthiplus.com RJ edition

www.vidyarthiplus.com

BE-CSE/IT/EEE REGULATION-2013

Semester-III

GE6351-ENVIRONMENTAL SCIENCE AND ENGINEERING

2 Mark Question with Answer

UNIT I – ENVIRONMENT, ECOSYSTEMS AND BIODIVERSITY

1. Define environment.

Environment is defined as the sum of total of all the living and non-living things

around us influencing one another.

2. What are all the categories of environment?

The main categories of environment are biotic and abiotic environments. The abiotic

environment can further be classified into atmosphere (air), lithosphere (soil), and

hydrosphere (water). The biotic environment is called as biosphere.

3. Define ecosystem.

A group of organisms interacting among themselves and with environment is known

as ecosystem. Thus an ecosystem is a community of different species interacting with one

another and with their nonliving environs exchanging energy and matter.

4. List any four characteristics of ecosystem.

(i). Ecosystem is the major ecological unit.

(ii). It contains both biotic and abiotic components.

(iii). The boundary of the ecosystem is not rigidly defined and it is flexible.

(iv). Through the biotic and abiotic components nutrient cycle and energy flow occur.

5. Write about autotrophic organisms.The producers are plants and bacteria, capable of producing their own food

photosynthetically or by chemical synthesis. These organisms are, thus, self-nourishing

as they can produce the as they can produce their own food by using the energy from the

physical environment surrounding them .them are also know as autotrophic organism or

producer.

6. Write about heterotrophic organisms

These organisms depend on other animals or on the food produced by other

8/17/2019 Ge6351 Cse Eee It

2/75



organisms for their nourishment, they are also called as heterotrophic organisms or

consumers.

7. What do you know about food chain and food web?A food chain is a picture or model that shows the flow of energy from Autotrophs to

a series of organisms in an environment. The network like interaction of organisms is

called as food web.

8. Define food chain.

The sequence of eating and being eaten in an ecosystem is known as food chain or

transfer of food energy from the plant through a series of organisms is referred to as food

chain.

9. Define ecological pyramids. How is it classified?

Graphical representation of structure and function of tropic levels of an ecosystem,

starting with producers at the bottom and each successive tropic levels forming the apex

is known as an ecological pyramids. It is classified into

i.

Primary succession

ii. Secondary succession

10. Define biodiversity. How is it classified? Biodiversity is defined as the variety and variability among all group of living

organisms and the ecosystem in which they occur. It is classified into

i. Genetic Level or Genetic diversity

ii. Species Level or Species diversity

iii. Ecosystem Level or Ecosystem diversity.

11. What are the two main functions of biodiversity?

1.

It is the source of species on which the human compete depends for food, fiber,

shelter, fuel and medicine.

2.

It depends on the biosphere, which in turn leads to the stability in climate, water,

soil, air, and the overall health of biosphere.

12. Define biogeography.

The study of the geographical distribution of biological species relating to the

geological, evolutionary, climatological, geographical, biological reasons for the

distribution is called biogeography

8/17/2019 Ge6351 Cse Eee It

3/75



13. Give the criteria for Biodiversity hotspots? i. Rich in plant and animal species, particularly many endemic species, and

ii. Under immediate threat from impacts such as land clearing, development

pressures, salinity, weeds and feral animals.

Example: Eastern Himalayas And western Ghats

14. What do you know about conservation of biodiversity?

Conservation is defined as the management of human use of the biosphere so that

it may yield the greatest sustainable benefit while maintaining its potential to meet the

needs and aspirations of future generations.

15. What is need for public awareness?

Increase in population, urbanization, poverty, has generated a lot of pressure on

natural resources resulting in the degradation of environment. Awareness is created

through government and Non government organization to protect the quality of the

environment.

16. What is meant by RED data book?

It is a book which lists endangered species of plants and animals. It gives awarning signal that if the species are not protected, they will become extinct.

17. What is meant by endangered species? Give examples.

They are species whose number has been reduced to a critical level, unless it is

protected, they will become extinct. E.g., Tortoise, Tiger, medicinal plants.

18. What is meant by endemic species? Give examples.

They are species which are found only in a particular region. They are mainly

found in Eastern Himalayas and Western Ghats. E.g., Nepenthes, reptiles, amphibians.

8/17/2019 Ge6351 Cse Eee It

4/75



8 Mark Question with AnswerUNIT I – ENVIRONMENT, ECOSYSTEMS AND BIODIVERSITY

1. Define the ecosystem. Give an account of the structure and function of

an ecosystem?

A group of organisms interacting among themselves and with environment is

known as ecosystem.

For example: Pond, lake, desert, grassland, forest, etc. The structure of an

ecosystem has two major components

A.

Biotic component (living)B. Abiotic Component( Non-living)

Structure of Ecosystem

A. Biotic component B. ABiotic component

a. Producer a.

Physical

component

b. Consumer b.

Chemical

component

1. Primary consumer (Herbivore)

2. Secondary consumer(primary carnivore)

3. Tertiary consumer (Secondary carnivore)

c.

Decomposer

A. BIOTIC COMPONENT (LIVING)

The living organisms or members in an ecosystem collectively form its community

called biotic components.

Member of Biotic components

a. Producer (plants)

8/17/2019 Ge6351 Cse Eee It

5/75



b. Consumer (animals)

c. Decomposer(Micro organisms)

a. ProducerThey prepare own food through photosynthesis. For examples : Plants, trees etc

b.

consumer

They directly or indirectly depend on the producer for their food.

They are three types.

1. Primary consumer (Herbivore – plant eater) They directly depend on the producer

for their food. For example : Insects, rat, goat, cow, horse, etc

2. Secondary consumer (primary carnivore – meat eaters) They directly depend upon

the primary consumer for their food. consumers. For example : Cat, Snakes, Foxes,

Frog, etc3. Tertiary consumer (Secondary carnivore – meat eaters)

They directly depend upon the primary carnivores for their food. For example :

Tigers, lions, etc.

c.

Decomposer

They attack the dead bodies of producers and consumers and decompose them into

simpler compounds (Inorganic and organic matters).

For example : Bacteria and Fungi.

B.

ABIOTIC COMPONENT( NON-LIVING)The Non-living organisms or members in an ecosystem collectively form its

community called abiotic components.

Member of Abiotic components

There are two

a. Physical components

They are useful for the growth and maintenance of its member.

For example : Air water, soil sunlight, etc.

b.

Chemical components

They are the sources of essential nutrients.

For example : Inorganic substance ( Al, Co, Zn, Cu, C, H,O, etc) and Organic

substance

( Proteins, Carbohydrates, etc)

Function of ecosystem

1. Primary function - Preparation of food through photosynthesis.

8/17/2019 Ge6351 Cse Eee It

6/75



2. Secondary function - Distributing energy in the form of food to all consumers.

3. Tertiary function - Nutrient cycle is maintained.

2. Explain the types of environment in detail.The term Environment can be broadly defined as one’s surroundings. The two

major classifications of environment are :

(A) Physical Environment: External physical factors like Air, Water, and Land etc. This

is also called the Abiotic Environment.

(B) Living Environment: All living organisms around us viz. plants, animals, and

microorganisms. This is also called the Biotic Environment.

Earth’s environment can be further subdivided into the following four segments:

(1) Lithosphere(2) Hydrosphere

(3) Atmosphere

(4) Biosphere.

Lithosphere

The earth’s crust consisting of the soil and rocks is the lithosphere. The soil is

made up of inorganic and organic matter and water. The main mineral constituents are

compounds or mixtures derived from the elements of Si, Ca, K, Al, Fe, Mn, Ti, O etc.

(Oxides, Silicates, and Carbonates). The organic constituents are mainly polysaccharides,organo compounds of N, P and S. The organic constituents even though form only around

4% – 6% of the lithosphere, they are responsible for the fertility of the soil and hence its

productivity.

Hydrosphere

This comprises all water resources both surface and ground water. The world’s

water is found in oceans and seas, lakes and reservoirs, rivers and streams, glaciers and

snowcaps in the Polar Regions in addition to ground water below the land areas.

Biosphere

The biosphere is a capsule encircling the earth’s surface wherein all the living

things exist. This portion extends from 10000 m below sea level to 6000 m above sea

level.

Atmosphere

It is the gaseous envelope surrounding the earth and extends upto 500 kms above

the earth’s surface. The atmosphere, which is a gaseous cover, protects the earth from

cosmic radiations and provides life sustaining Oxygen, the macronutrient Nitrogen and

Carbon dioxide needed for photosynthesis. The atmosphere screens the dangerous UV

8/17/2019 Ge6351 Cse Eee It

7/75



radiations from the sun and allows only radiations in the range of 300 nm – 2500 nm

(near UV to near IR) and radio waves. The atmosphere plays a major role in maintaining

the heat balance of the earth by absorbing the re-emitted radiation from the earth. Inaddition the atmosphere is the medium of carriage of water from the oceans to the land in

the hydrological cycle.

3. Explain the Structure of the Atmosphere

The atmosphere is broadly divided into four major zones. Troposphere,

Stratosphere, Mesosphere and Thermosphere.

Troposphere

Troposphere is the layer of air nearest to the ground. Temperature decreases

with height. The average temperature drops from 15ºC at sea level to –56.5ºC at 11,000m above sea level. Mixing of the air molecules due to their constant movement (winds)

keeps the composition of the gases more or less same throughout the troposphere. An

exception to this is water vapor. Most water vapor evaporates from the surface of the

Earth and is found in the lower troposphere. Most of the weather occurs in the

troposphere. Tropopause is the top of the troposphere, which is a transition layer between

Troposphere and Stratosphere

Stratosphere

Stratosphere is the layer of air above the troposphere where temperatureincreases with height. The average temperature rises to –2.5ºC at 50,000 m above sea

level. Ozone is found in higher concentrations between 20 and 30 km above the surface.

Hence sometimes this layer is referred to as the “ozone layer”. Ozone absorbs radiant

energy from the sun and hence warmer temperatures are encountered in the stratosphere.

Stratopause is the top of the stratosphere, which is a transition layer between Stratosphere

and Mesosphere.

Mesosphere

Mesosphere is the layer of air above the stratosphere where temperature

decreases with height. The average temperature decreases to –90°C at 90,000 m. This is

the coldest layer of the atmosphere. Mesopause is the top of the mesosphere, which is a

transition layer between Mesosphere and Thermosphere.

Thermosphere

Thermosphere is the layer of air above the mesosphere. The temperatures in the

thermosphere increase with increasing height, but there are not many molecules in this

layer. The air becomes less and less dense as we reach space.

8/17/2019 Ge6351 Cse Eee It

8/75



4. Write the short notes on energy flow in ecosystem.The sun is the source of all our energy. It is a continuously exploding hydrogen

bomb where hydrogen is converted to helium with the release of energy. This energy is

mostly in the region of 0.2 to 4 m m (Ultraviolet to Infra Red). Around 50% of the

radiation is in the visible range. The energy reaches the earth at a constant rate called the

Solar Flux or Solar Constant, which is the amount of radiant energy crossing unit area in

unit time. This value is approximately 1.4 KJ per sq. meter per second. Chlorophyll

bearing plants convert this energy from the sun into carbohydrates and sugars using

carbon di oxide and water. This process is known as Photosynthesis

.The generalized form of the photosynthetic reaction is

6CO2 + 12H2O —C6H12O6 + 6O2 + 6H2O

Carbon dioxide + water —glucose + oxygen + water

The carbohydrates produced by photosynthesis undergo further modifications such as

production of proteins and nucleic acids by combining with nitrogen, phosphorous and

sulphur. Starch polymerizes to cellulose. The sun’s energy thus enters the living beings

through photosynthetic reactions and is passed from one organism to another in the form

of food. The flow of energy is unidirectional and is governed by the thermodynamic law

that states that Energy is neither created nor destroyed and can transform into differentforms.

5. Write the importance of Biodiversity.

Biological diversity is very important for the existence of the human race. In

addition to the practical importance, Biodiversity lends aesthetic beauty to nature. The

benefits arising from biological diversity are:

Ecosystem Services

• Protection of water resources like maintenance of hydrological cycles, regulating and

stabilising water runoff, and buffer against extreme events such as flood and drought.

• Soils formation and protection: Formation and maintenance of soil structure and the

retention of moisture and nutrient levels.

• Nutrient storage and cycling: Plants take up nutrients from the soil as well as from the

air, and these nutrients can then form the basis of food chains, to be used by a wide range

of other life forms. Pollution breakdown and absorption

8/17/2019 Ge6351 Cse Eee It

9/75



• Breakdown and absorpion of pollutants: Ecosystems and components of ecosystems

from bacteria to higher life forms are involved in breakdown and assimilative processes

of pollutants. Natural and artificial wetlands are being used to filter effluents to removenutrients, heavy metals and suspended solids, reduce the biochemical oxygen demand

and destroy potentially harmful microorganisms.

• Contribution to climate stability: Vegetation influences climate at the macro and

micro levels. Undisturbed forest helps to maintain the rainfall in its immediate vicinity by

recycling water vapour at a steady rate back into the atmosphere.

• Recovery from unpredictable events: Healthy ecosystems improve the chances of

recovery of plant and animal populations from unpredictable natural catastophic events

such as fire, flood and cyclones and from disasters caused by humans.

6. Explain the in-situ conservation along with their merits and limitations.

It involves protection of plants and animals within its natural habitat is called in-situ

conservation. For example: Biosphere reserves, National parks, wildlife sanctuaries,

Gene sanctuary, etc

Methods of in-situ conservation.

a. Biosphere

It covers large area, more than 5000 sq. km.

For example1. Nanda devi-U.P.

2. Manas – Assam

3. Gulf of mannar – Tamil Nadu

4. Nilgiri – Karnataka, kerala, tamil nadu

b. National park

It covers small area about 500 sq. km

For example

1.

Gir national park - Gujarat

2. Bandipur – Karnataka

3. Corbett – U.P.

4. Kanha – M.P.

5. Periyar - kerala

c. Wild life sanctuaries

It is a reserved area for the conservation of animals only. There are 492 wildlife

8/17/2019 Ge6351 Cse Eee It

10/75



sanctuary in India.

For example

1.

Ghana Bird sanctuary – Rajasthan2. Vedanthangal Bird sanctuary – Tamil Nadu

3. Muthumalai wildlife sanctuary – Tamil Nadu

4. Wild ass sanctuary – Gujarat

d. Gene Sanctuary

It is an area for the conservation of plants only.

For example

1. Gene sanctuary for citrus – North India

2.

Gene sanctuary for pitcher plant – North India .Advantages of In-situ

1. It is very cheap and convenient method.

2. The species gets adjusted to the natural disasters.

Disadvantages of in-situ

1. Large surface area is needed to conserve biodiversity.

2. Maintenance of the habitat is not proper, due to shortage of staff and pollution.

7. Explain the Ex-situ conservation along with their merits and limitations.

It involves protection of plants and animals outside the natural habitat is called in-situ conservation. For example : Botanical gardens, Zoological gardens, seed bank, tissue

& cell cultures

Methods of ex-situ conservation

1. National Bureau of plant Genetic resources (NBPGR)

It is located in new delhi. It uses cryo preservation techniques to preserve

agricultural and horticultural crops Cryo preservation techniques. The variety of

agricultural and horticultural crops have been preserved by using liquid nitrogen at -196o

C .

2. National Bureau of animal Genetic resources (NBAGR)

It is located at karnal, Haryana It is used to preserve the semen of domesticated bovine

animals.

3.

National facility for plant tissue culture repository (NFPTCR)

It is used to conserve the variety of plants or trees by tissue culture. It is created within

the NBPGR.

8/17/2019 Ge6351 Cse Eee It

11/75



Advantages of Ex-situ conservation

1. Survival of endangered species

2.

Longer the life spanDisadvantages of Ex-situ conservation

1. It is expensive method

2. The freedom of wildlife is lost

3. The animals cannot survive in natural environment.

8. Explain the various Threats to and the measures for conservation of biodiversity

1. Habitat loss

Deforestation activities (cutting trees for timber, removal of medicinal plants)Production of hybrid seeds requires wild plants as raw material, farmers prefer hybrid

Seeds, many plant species become extinct . Increase in the production of pharmaceutical

companies made several number of medicinal plants and species on the verge of

extinction. Removal of forest-cover for road laying and also due to soil erosion. Illegal

trade of wild life Population explosion, construction of dam, discharge of industrial

effluents use of pesticides.

2. Poaching of wild life

Due to poaching, illegal trade and smuggling activities most of our valuable fauna are

under threat organized crime has moved into illegal wild life smuggling because of huge

profit.

Eg. Tiger, Deer – for hides,

Rhinoceros – for horns,

Elephant – for ivory tusk,

The climate change caused by our release of green house gases in the atm. could

have catastrophic effects. Human disturbance of natural habitat is the largest single cause

of loss of biological diversity. Woodlands and grasslands are converted now use about

10% of the worlds land surface for crop production and about twice the amount for

pasture and grasslands.) Hunting: Over harvesting is responsible for depletion or

extinction of many species. E.g., The American passenger pigeon was the world’s most

abundant bird. In spite of this vast population, market hunting and habitat destruction

caused the entire population to crash within 20 years.

8/17/2019 Ge6351 Cse Eee It

12/75



3. Fragmentation

Habitat fragmentation reduces the biodiversity because many animals like bears and

large cats require large territories to subsist. Some forest birds reproduce only in deepforest or habitat far from human settlement. A large island for example, can support more

individuals of given species and therefore less likely to suffer extinction due to genetic

problems and natural catastrophes.

Commercial products:

Smuggling of fuels, hides, horns and folk medicines also affect the biodiversity in

an abrupt manner

9. Explain the values of bio-diversity with suitable examples

Direct values

The direct value include food resources like grains, vegetables, fruits which are

obtained from plant resources and meat, fish, egg, milk and milk products from animal

resources. These also include other values like medicine, fuel, timber, fiber, wool, wax,

resin, rubber, silk and decorative items.

The direct values are of two types

(i) Consumptive use value and

(ii) Productive use value.

Consumptive use value:

8/17/2019 Ge6351 Cse Eee It

13/75



These are the direct use values where the biodiversity products can be harvested

and consumed directly. Example: Food, fuel and drugs. These goods are consumed

locally and do no figure in national and international market.

(a) Food:

The most fundamental value of biological resources particularly plants is

providing food. Basically three crops i.e. wheat, maize and rice constitute more than two

third of the food requirement all over the world.

(b) Fuel:

Since ages forests have provided wood which is used as a fuel. Moreover fossil fuels

like coal, petroleum, natural gas are also product of biodiversity which are directly

consumed by humans.

(c) Drugs and medicines:

The traditional medical practice like ayurveda utilizes plants or their extracts

directly. In allopathy, the pharmaceutical industry is much more dependent on natural

products. Many drugs are derived from plants like

(i) Quinine : The famous anti malaria drug is obtained from cinchona tree.

(ii) Penicilli : A famous antibiotic is derived from pencillium, a fungus.

(iii) Tetracycline: It is obtained from bacterium.

Productive use values:

These are the direct use values where the product is commercially sold in national and

international market. Many industries are dependent upon these values. Example- Textile,

leather, silk, paper and pulp industry etc. Although there is an international ban on trade

of products from endangered species like tusks of elephants, wool from sheep, fur of

many animals etc. These are traded in market and fetch a booming business.

8/17/2019 Ge6351 Cse Eee It

14/75



Indirect values

Biodiversity provides indirect benefits to human beings which support theexistence of biological life and other benefits which are difficult to quantify. These

include social and cultural values, ethical values, aesthetic values, option values and

environment service values.

Social and cultural value:

Many plants and animals are considered holy and sacred in India and are

worshipped like Tulsi, peepal, cow, snake etc. In Indian society great cultural value is

given to forest and as such tiger, peacock and lotus are named as the national animal, bird

and flower respectively.

Ethical value:

These values are related to conservation of biodiversity where ethical issue of ‘all

life forms must be preserved’ is laid down. There is an existence value which is attached

to each species because biodiversity is valuable for the survival of human race. Moreover

all species have a moral right to exist independent of our need for them.

Aesthetic value:

There is a great aesthetic value which is attached to biodiversity. Natural

landscapes at undisturbed places are a delight to watch and also provide opportunities for

recreational activities like bird watching, photography etc. It promotes eco-tourism which

further generates revenue by designing of zoological, botanical gardens, national parks,

wild life conservation etc.

Option values:

These values include the unexplored or unknown potentials of biodiversity.

The most important benefit of biodiversity is maintenance of environment services which

includes

(i) Carbon dioxide fixation through photosynthesis.

(ii) Maintaining of essential nutrients by carbon (C), oxygen (O), Nitrogen (N),

Sulphur (S), Phosphorus (P) cycles.(iii) Maintaining water cycle and recharging of ground water.

(iv) Soil formation and protection from erosion.

8/17/2019 Ge6351 Cse Eee It

15/75



UNIT II – ENVIRONMENTAL POLLUTION

1. Define pollution.Environmental pollution may be defined as the unfavorable alteration of our

surroundings its change the quality of the air, water and land which interferes with the

health of humans and other life on earth.

2. Define air pollution.

Air pollution is defined as the presence of one or more contaminates like dust,

smoke, mist and odour in the atmosphere which are injurious to human beings, plants and

animals.

3. Define photo chemical smog.

A photochemical reaction is any chemical reaction activated by light that air

pollution knows as photochemical smog is a mixture of more than 100 primary and

secondary pollutants formed under the influence of sun light. Its formation begins inside

automobile engines and the boilers an in coal-burning power and industrial plants.

4. What do you know about particulate matter?

In general the term ‘particulate matter’ refers to all atmospheric substances that are

not gases. They can be suspended droplets or solid particles or mixtures of the two.Particulates can be composed of materials ranging in size from 100mm down 0.1 mm and

less. The chemical composition of particulate pollutants is very much dependent upon the

origin of the particulate.

5. Differentiate between Mist and Fog.

Mist is made up of liquid droplets generally smaller than 10um which are formed

by condensation in the atmosphere or are released from industrial operations.

Fog is similar to mist but the droplet size bigger (> 10u) and water is the liquid.

Fog is sufficiently dense to incomprehensible vision.

6. List some of the effects of air pollution on physical properties of atmosphere.

a. Decrease in the visibility

b. Reduction of Solar radiation.

c. Effects on weather conditions.

d. Effects on atmospheric constituent.

8/17/2019 Ge6351 Cse Eee It

16/75



7. How air pollution can be controlled at source?

a. Proper use of the existion equipment

b.

Change in process.c. Modification or Replacement of equipments.

d. Installation of controlling equipments.

8. Define water pollution.

Water pollution may be defined as the alteration in physical, chemical and

biological characteristics of water which may cause harmful effects on humans and

aquatic life.

9. What are the effects of in organic substances in water?a. Makes the water unfit for drinking and other purposes.

b. Corrosion of metals exposed to such waters.

c. Causes skin cancers, damages to spinal,CNS, liver and kidneys.

d. Reduces crop yield.

10. How do the nutrients from agricultural fields affect the watershed?

Enrichment of nutrients (Eutrophication) from surrounding watershed affects the

penetration of light through the water, causing damage to the characteristic of water and

aquatic life.

11. Define soil pollution.

Soil pollution is defined as the contamination of soil by human and natural

activities which may cause harmful effects on living beings.

12. Define marine pollution.

Marine pollution is defined as the discharge of waste substance into the sea

resulting in harm to living resource, hazards to human health, hindrance to fishery and

impairment of quality for use of sea water.

13. Define noise pollution. Mention the types of noise.

Noise pollution is defined as the unwanted, unpleasant or disagreeable that causes

discomfort for all living beings. The types of noises are Road traffic noise, Air traffic

noise, Rail traffic noise, Domestic noise and Industrial noise

8/17/2019 Ge6351 Cse Eee It

17/75



14. Define thermal pollution.

Thermal pollution is defined as the addition of excess of undesirable heat to water

that makes it harmful to man, animal or aquatic life or otherwise causes significantdepartures from the normal activities of aquatic communities in water.

15. What are solid wastes?

The wastes generated and discarded from human and animal activites that are

normally solid are called as solid wastes.

16. What is meant by on –site handling?

The activities involved in handling of solid wastes, at the point of generation, until

they are placed in the containers used for their storage before collection are called as on – site handling. Handling requires to move the filled containers to the collection point and

to return the empty containers to the generation point for the next collection.

17. What is the purpose of on-site processing?

On-site processing of solid wastes is used to recover the reusable materials from

the solid wastes. This process also helps in reducing the volume of solid wastes or

altering the physical form of the solid wastes.

18. What are the main purposes of processing techniques used in solid waste

management?

1. To improve the efficiency of solid waste management systems

2. To recover the usable materials for reuse.

3. To recover conversion products and energy.

19. What are biomedical wastes?

Biomedical wastes are defined as any solid, semi solid or liquid waste including its

containers and any intermediate product which are generated during diagnosis, treatment

or immunization of human being/ animals or in production and testing of biological parts.

8/17/2019 Ge6351 Cse Eee It

18/75



UNIT II POLLUTION AND ITS CONTROL

1. Explain the sources, effect and control measures of noise pollution. Sound is mechanical energy from a vibrating source. Unpleasant and unwanted

sound is called noise. It has a dimensionless unit decibel (dB).

For example

1. Rocket engine – 180 dB

2. Motor cycle – 90 dB

3. Normal living room – 50 dB

4. Library or soft whisper – 30 dB

Sources of noise pollution Noise pollution is a growing problem. All human activities contribute to noise

pollution to varying extent. Sources of noise pollution are many and may be located

indoors or outdoors.

Indoor sources include noise produced by radio, television, generators, electric

fans, air coolers, air conditioners, different home appliances, and family conflict. Noise

pollution is more in cities due to a higher concentration of population and industries and

activities such as transportation. Noise like other pollutants is a byproduct of

industrialization, urbanization and modern civilization.

Outdoor sources of noise pollution include indiscriminate use of loudspeakers,

industrial activities, automobiles, rail traffic, aeroplanes and activities such as those at

market place, religious, social, and cultural functions, sports and political rallies. In rural

areas farm machines, pump sets are main sources of noise pollution. During festivals,

marriage and many other occasions, use of fire crackers contribute to noise pollution.

Effects of noise pollution

Noise pollution is highly annoying and irritating. Noise disturbs sleep, causes

hypertension (high blood pressure), emotional problems such as aggression, mental

depression and annoyance. Noise pollution adversely affects efficiency and performance

of individuals.

Prevention and control of noise pollution

Following steps can be taken to control or minimize noise pollution-

8/17/2019 Ge6351 Cse Eee It

19/75



• Road traffic noise can be reduced by better designing and proper maintenance of

vehicles.

•

Noise abatement measures include creating noise mounds, noise attenuation walls andwell maintained roads and smooth surfacing of roads.

• Retrofitting of locomotives, continuously welded rail track, use of electric

locomotives or deployment of quieter rolling stock will reduce noises emanating from

trains.

• Air traffic noise can be reduced by appropriate insulation and introduction of noise

regulations for takeoff and landing of aircrafts at the airport.

• Industrial noises can be reduced by sound proofing equipment like generators and

areas producing lot of noise.

•

Power tools, very loud music and land movers, public functions using loudspeakers,etc should not be permitted at night. Use of horns, alarms, refrigeration units, etc. is to

be restricted. Use of fire crackers which are noisy and cause air pollution should be

restricted.

• A green belt of trees is an efficient noise absorber.

2. Discuss the causes, effect and control measure of air pollution.

It is defined as the presence of one or more contaminants like dust, smoke, mist

and odour in the atmosphere which are injurious to man and his environment.

Ex. Gases, particulate matter, radioactive substances etc.

Sources of air pollution

Effect of air Natural sources

Man Made

Sources(anthropogenic)

1. Volcanic eruption thermal power plants (fly ash, SO2)

2. Forest fires industrial units, vehicle emission

3. Pollen grains of flowers

Agricultural activities

Metallurgical plants (SO2, CO2)

Fertilizer plants

Textile mills

Refineries

Paper and pulp mills

8/17/2019 Ge6351 Cse Eee It

20/75



pollution

1. Effect on human beings

2.

Effect on plants3. Effect on Materials

4. Effect on aquatic life

Example

1. Carbon monoxide (CO) – this react with heamoglobin and reduce the carrying

capacity of O2 which cause headaches, anemia, coma mental disorder and death.

2. Nitrogen dioxide (NO2) – lung irrigation and damage

3. Sulphur dioxide (SO2) – Breathing problems

4. Suspended particulate matter (SPM) – Nose and throat irritation, lung damage,

bronchitis, asthma, reproductive problems and cancer.5. Ozone (O3) – chemical reaction with organic compounds and moderates the

climate.

6. Photochemical smog – the brownish smoke due to chemical reactions among

nitrogen oxides and hydrocarbon by sunlight.

Control of air pollution:

1. Using non conventional energy

2. Using bio filters

3.

Planting more trees4. Reducing vehicle exhausts

5. Using less polluting fuels

6. Removal of particulate matter using electrostatic precipitator, cyclone filter etc.

7. Removal of NOX from vehicle exhaust .

3. Discuss the causes, effects and control measure of Water pollution.

It is defined as the alteration of physical, chemical and biological characteristics of

water which may cause harmful effects on humans and aquatic life.For example: sewage, industrial effluents, etc

Causes:

1. Point source – they are discharged pollutants at specific locations For example:

sewage, industrial effluent etc.

2. Non-point source- they cannot be traced to any single site of discharge. For Ex:

agricultural land (pesticides, fertilizers, mining, construction sites), urban street.

8/17/2019 Ge6351 Cse Eee It

21/75



Classification of water pollutants:

1. pathogens (bacteria, fungi, protozoa fungi)

2.

oxygen demanding wastes3. inorganic chemicals

4. organic chemicals

5. plant nutrients

6. sediment

7. Radioactive waste

8. Excess heat

Effects of water pollution

1.

Objectionable colour and odour is unacceptable and unsuitable for drinking andother purposes.

2. highly turbid and very hard water is unpleasant to drink, food processing

3. acid and alkaline water cause serious health problem

4. water borne infectious enteric disease like typhoid, cholera, dysentery, are the

predominant health hazard arising from drinking contaminated water

5. radioactive pollution enter human body through food and get accumulated in

thyroid gland, liver, bones and muscles

6. biodegradable waster deplete dissolved oxygen in the receiving stream, affect the

flora cause creates anaerobic conditions7. non biodegradable waste and pesticides travel the food chain and ultimately reach

human where they accumulate in fatty tissues

8. thermal discharge in stream depletes dissolved oxygen

9. phosphate, nitrate, promote the growth of algae and encourage eutrophication

10. Industrial effluents result in addition of poisonous chemicals such as arsenic,

mercury, lead may reach human body through contaminated food.

Control measure of water pollution

1.

Afforestation

2. Public awareness

3. Strictly implement the water act against offenders

4. treatment

4. Explain the methods of disposal of municipal solid waste.

This includes the waste generation, mode of collection, transportation,

8/17/2019 Ge6351 Cse Eee It

22/75



separation of wastes and disposal techniques.

Steps involved in Solid waste management

1.3R- approach 2. Discarding wastes

a. Reduce a. Landfill

b. Reuse b. Incineration

c. Recycle c. Compositing

1.

3-R approach

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

a. Reduce- If the usage of raw materials are reduced, the generation of waste also

gets reduced.

b. Reuse- Refillable container and rubber rings after use can be reused.

c. Recycle- It is reprocessing of the discarded materials in to new useful

products.

2.

Discarding wastes: It is a technique to dispose the municipal solid waste

a. Landfill

This method involves spreading the solid waste with 80cm thickness on the ground,

compacting it and then covering it with soil with 20 cm thickness. After two or three

years solid waste shrinks by 25-30% and land is used for parks, roads and small

buildings.

Advantages

1. It is simple and economical.

2.

separation is not required

3. It converts low lying, waste land into useful areas.

Disadvantages

1. Large area is required

2. Transportation cost is heavy because of distance of land

3. bad odours

4. causes fire hazard due to the formation of methane in wet weather.

8/17/2019 Ge6351 Cse Eee It

23/75



b. Incineration

Incineration is a process to burn the municipal solid waste in a furnace. The

combustible waste are separated form non-combustible waste. The combustiblewaste(100-150 tones per hour) are feeding to incinerator and heated about 700

o C. The

left out ashes an clinkers in the incinerator. These are disposed by sanitary landfill

method.

Advantages

1. It require the little space

2. It is a hygienic way of disposing the solid waste

Disadvantages

1. It is capital and operating cost is high.

2.

Formation of smoke, dust and ashes makes air pollution

c. Compositing

The bulk organic waste is converted into a natural fertilizer by biological action

is known as composting.

This method involves the separated compostable waste is dumped in underground

earth trenches in layers of 1.5 m and finally covered the earth soil with 20cm thickness

and left over for decomposition. Certain microorganisms such as actinomycetes are

introduced for active decomposition. After one or two month, the brown colored,

odourless mass known as humus(natural fertilizer) which can be used for agriculturalfield

Advantages

1. When the manure is added to soil, it increases the water retention and ion-

exchange capacity of soil.

2. No of industrial solid waste treated by this method

3. Recycling occurs

Disadvantages

1.

The non-consumables have to dispose separately.

2. The compost has no assured market value.

5. Explain the sources, effects and control measures of Thermal pollution.

Addition of excess undesirable heat to water

Causes:-

i. Nuclear power plant

ii. Domestic sewage

8/17/2019 Ge6351 Cse Eee It

24/75



iii. Hydro electric power

Effects:-i. Reduction inn dissolved oxygen

ii. Increase in toxicity

iii. Direct mortality

Control measures:-

The following methods should be adopted to control thermal pollution

i. Cooling towers

ii. Cooling ponds

iii. Spray ponds

6. Explain the sources, effects and control measures of Nuclear pollution?

The physical pollution of air, water and soil by radio materials. Causes:-

I) Natural causes:

i. Solar rays

ii. Radio nuclides in earth‟s crust

iii. Environmental radiation

II) Anthrogeneic causes:-

i.

Medical X-rays

ii. Radio isotopes

iii. Nuclear test

iv. Nuclear installations

v. Nuclear reactor

Effects:-

i. Causes skin burns, loss of teeth, vomiting anemia

ii. Blood cancer

iii.

Brain damageControl measures:-

i. Radiation exposure protection

ii. Radiation contamination protection

iii. Controlled area

iv. Disposal of radioactive waste

The contamination of soil by human and natural activities which may cause

harmful effects on living beings. Causes:-

i. Industrial waste

8/17/2019 Ge6351 Cse Eee It

25/75



ii. Urban waste

iii. Agricultural practices

iv.

Radioactive pollutantsv. Biological agent

Effects:-

i. Affect human health

ii. Affect soil fertility

iii. Reduce soil productivity

Control measures:-

i. Properly collect solid waste

ii.

Microbial degradationiii. Recovery of products from waste

iv. For methane generation, use cattle dung

v. For biogas generation, use biodegradable organic waste.

7. Explain the source, effect and control measures of Marine pollution.

The discharge of waste substances into the sea resulting in harm to living

resources, hazards to human health, hindrance to fishery and impairment of quality for

use of sea water.

Causes:-

i. Rivers

ii. Catchment area

iii. Oil drilling and shipment.

Sources:

i. waste disposal

ii. oil spill

iii. thermal pollution (plants located nearby coastal areas)

iv. ship breaking activities

v. aquaculture practices

vi. nuclear test conducted in seas and oceans

Effects:

i. disturbs entire aquatic or marine ecosystem

ii. oil has suffocation effect on most aquatic animals, smaller animals can be

caught in oil envelope and die

iii. Thermal Pollution may increase the temperature of water and DO may be

depleted which causes danger.

8/17/2019 Ge6351 Cse Eee It

26/75



iv. There may be chances for bioaccumulation and bio magnification in the

food chain due to the disposal of non-degradable wastes

v.

Oil promotes anaerobic conditions by preventing diffusion of oxygen fromair

vi. Disposal of radio active wastes cause chronic, acute and genetic damage

vii. Affects the recreational activity along the beaches

viii. Affect sensitive flora and fauna

ix. Loss of buoyancy

x. Effects phytoplankton, zooplankton, algal species, coral reefs, fish, birds

and mammals.

Control measures:-

i.

Ban to dump the toxic, hazards waste and sewage sludge.ii. Prevent sewer overflows

iii. Minimize coastal developmental activities

iv. Oil ballast should not be dumped into sea.

8. Write short notes on Flood and Cyclone

Flood:

Submergence of waste areas of land under water for many days in continuation

Causes: 1.Heavy rainfall 2. Sudden Snow melt 3. Clearing of forest for agriculture 4,

Industries increase the value and rate of water discharge after a storm Effects:

1. Damage to building and property

2. Soil erosion is the major loss of agriculture

3. Any product submerged by flood water cannot be rescued

Control measures:

1. Building wall prevent spilling out the flood water over flood pains

2. advance meteorological information will prevent flood damage3. reduction of run off by increasing infiltration through appropriate forestation eg.flood

in Bangladesh 1974

Cyclone:

Cyclone is meteorological phenomena intense depressions forming over the open

oceans and moving towards the land Effects:

1. Depends on the intensity of the cyclone

2. Damage to human life crops roads, transport, communication could be very heavy

8/17/2019 Ge6351 Cse Eee It

27/75



Control measures:

1. planting more trees on hostel areas2. construction of dams

3. Radar system is used to detect cyclone eg.Cyclone in AP

9. What is Earthquake? Enumerate its effects .What measures should be taken to

mitigate their disaster?

Earthquake is the motion of the ground surface caused by wave motion starting

from a focal point Causes:

1. Underground nuclear testing

2. Volcanic eruption

3. Pressure of manmade dams, reservoir and lakes

4. Movements of plates of earth

Effects:

1. Cause Tsunami

2. Deformation of ground surface

3. In hilly and mountain areas may cause land slides which damage the settlement and

transport system4. Depending on the severity of the quake collapses house and people died in 1000 eg.

Earthquake in Bhuj town.

Control measures:

1. Government can inform the earthquake prone zone and caution residence

2. building should be designed to withstand tremors.

10. Write short notes on Landslides.

The movement of eart materials like coherent rock, mud, soil and debris fromhigher region to lower due to gravitational pull is called landslide Causes:

1. Earthquake, shock, vibration

2. Deep water ground mining

3. Movement of heavy vehicles on the unstable sleepy region

Effects:

1. Increase erosion of soil

8/17/2019 Ge6351 Cse Eee It

28/75



2. block the roads

3. damage the houses, crop yield, life stock

Control measures:

1. Planting of deep rooted vegetation

2. Encouragement for construction of bridges water ways

3. Create national parks, sanctuaries biosphere.e.g.land slides in U.P .

11. Discuss the causes, effect and control measure of Soil pollution.

Addition of substances which adversely affect the quality of soil or its fertility is

known as soil pollution.

1) Solid waste is a mixture of plastics, cloth, glass, metal and organic matter,

sewage, sewage sludge, building debris, generated from households, commercial and

industries establishments add to soil pollution.

2) Fly ash, iron and steel slag, medical and industrial wastes disposed on land are

important sources of soil pollution.

3) Acid rain and dry deposition on land surface also contribute to soil pollution.

Sources of soil pollution

Plastic bags – Plastic bags made from low density polyethylene (LDPE), is

virtually indestructible, create colossal environmental hazard. The discarded bags block

drains and sewage systems. Leftover food, vegetable waste etc. on which cows and dogs

feed may die due to the choking by plastic bags. Plastic is non biodegradable and burning

of plastic in garbage dumps release highly toxic and poisonous gases like carbon

monoxide, carbon dioxide, phosgene, dioxine and other poisonous chlorinated

compounds.

Industrial sources – It includes fly ash, chemical residues, metallic and nuclear

wastes. Large number of industrial chemicals, dyes, acids, etc. find their way into the soil

and are known to create many health hazards including cancer.

Agricultural sources – Agricultural chemicals especially fertilizers and pesticides

pollute the soil. Fertilizers in the run off water from these fields can cause eutrophication

in water bodies. Pesticides are highly toxic chemicals which affect humans and other

animals adversely causing respiratory problems, cancer and death.

Control of soil pollution

To control soil pollution, it is essential to stop the use of plastic bags and instead

use bags of degradable materials like paper and cloth. Sewage should be treated properly

8/17/2019 Ge6351 Cse Eee It

29/75



before using as fertilizer and as landfills. The organic matter from domestic, agricultural

and other waste should be segregated and subjected to vermicomposting which generates

useful manure as a by product. The industrial wastes prior to disposal should be properlytreated for removing hazardous materials. Biomedical waste should be separately

collected and incinerated in proper incinerators.

8/17/2019 Ge6351 Cse Eee It

30/75



UNIT III – NATURAL RESOURCES

1. Define renewable resources and non renewable resources.The renewable resources are those resources which have the inherent capacity to

reappear by quick recycling, reproduction, and replacement within a reasonable time, and

to maintain themselves. Example; air, water, soil (land), and plants, and animals

The non-renewable resources are those that do not have the ability for recycling and

replacement within a reasonable period of time.

Example; minerals, coal oil, natural gas, ground water.

2. Define deforestation.

Deforestation is the process of removal of (or) elimination of forest resources due tomany natural or man-made activities. in general deforestation means destruction of

forests.

3. Define drought.

Drought is nothing but scarcity of water, which occurs due to inadequate rainfall,

late arrival of rains and excessive withdrawal of ground water.

4. Define food resources.

Food is an essential requirement for the human survival. Each person hasminimum food requirement, the main components of food are carbohydrates, fats protein,

minerals, and vitamins.

5. What is hydrological cycle?

The water from various water bodies gets evaporated by the solar energy, and falls

again on the earth in the form of rain or snow and enter into the living organisms and

plants and ultimately returns to the ocean .this process is called hydrological cycle.

Clouds →water (ocean, lake, river) →living organisms &plants.

6. Define floods.

A flood is an overflow of water, whenever the magnitude of flow of water exceeds

the carrying capacity of the channel within its banks.

7. Write short notes on Tidal energy.

Tides, the alternate rise and fall of sea water possess lot of energy. The identified

tidal power potential in India is around 9000 MW. Currently France, Russia, china and

8/17/2019 Ge6351 Cse Eee It

31/75



Canada are effectively utilizing the tidal energy to produce 2 to 3% of their energy

demand.

8. Define Soil Erosion.

Soil erosion is the movement of soil components, especially surface litter and top

soil, from one place to another. The two main movers are flowing water and wind.

9. Define drought.

Drought is nothing but scarcity of water which occurs due to inadequate rainfall,

late arrival of rains and excessive withdrawal of ground water.

10. Write short note on blue baby syndrome. When the nitrogenous fertilizers are applied in the fields they leach deep into the

soil the contaminate the ground water. the nitrate concentration in the water gets

increased. When the nitrate concentration exceeds 25mg /lit they cause series health

problems called blue baby syndrome this disease affects infants and leads even to

death.

11. Define wind energy.

Moving air is called wind. Energy recovered from the force of the wind is called

wind energy. The energy possessed by wind because of its high speed. The wind energyis harnessed by making use of wind mills.

12. Define geo thermal energy.

Temperature of the earth increases at a rate of 20-75ºC per km, when we move

down the earth surface. High temperature and high pressure steam fields exist below the

earth’s surface in many places. The energy harnessed from the high temperature present

inside the earth is called geothermal energy.

13. List some ways to protect soil.

a. When the buildings are constructed, all the trees shall be saved.

b. Setting a composite bin and it shall be used for producing mulch and soil

c .Conditioner for yard and garden plants organic methods can be used for

growing vegetables.

d. Strictly enforcing laws and policies that minimize soil erosion, salt buildup and

water logging.

8/17/2019 Ge6351 Cse Eee It

32/75



UNIT – 3 – NATURAL RESOURCES

1.

What is deforestation? Explain the causes and consequences ofdeforestation?

It is the process of removal or elimination of forest resources due to natural or

man-made activities

Causes of deforestation:

1. developmental projects –Dam, road construction, etc

2. Mining operations

3. raw materials for industrial use

4. fuel requirement

5.

Shifting of Cultivation6. growing food needs

7. forest fire

Consequences of deforestation:

1. Global warming

2. biodiversity is lost along with that genetic diversity

3. soil erosion and loss of soil fertility

4. hydrological cycle is affected

(loss of rainfall, flood, drought etc)

2. What is mining? Discuss classification & the environmental effects of extracting

and using mineral resources?

Mining is a process of removing ores from area which is very much below the ground

level. Mining is done for the extraction of several minerals of metals like Fe, Mn, Au,

Ag, etc. The minerals are especially found in thick forests.

Mining can be carried out in two ways

1. Surface mining

2.

underground mining or sub-surface mining

Classification of minerals

Minerals are classified into two ways based on their composition and usage.

1)Based on composition

1. Metalic minerals – various metals can be extracted for example : Fe, Al, Cu, Zn

2. Non – Metalic minerals – various non-metalic compound can be extracted. For

example : quartz, dolomite, calcite,etc

8/17/2019 Ge6351 Cse Eee It

33/75



2)Based on usage

1. Critical minerals - These are essential of the economic power of a country. For eg: Fe,

Al, Cu etc2. Strategic minerals. - These are required for the defence of a country. For example :

Mn, Co, Pt, etc

Environmental effects of extracting and using mineral resources:

1.Devegetation an defacing of landscape

2.Ground water contamination

3.Surface water pollution

4. Air pollution

5. Subsidence of land

3. What is agriculture? Explain its types and adverse environmental impacts of

modern agriculture?

It is an art, science and industry of managing the growth of plants and animals for

human use.

Types of Agriculture

There are two types

1. Traditional agriculture

2.

Modern agriculture

1. Traditional agriculture

It involves a small plot, simple tools, surface water, organic fertilizers and a mix

of crops.

Effect of Traditional agriculture

a. Deforestation- Removal of trees for cultivation purpose.

b. Soil erosion- Top soil removed by wind and rainfall, resulting in loss of soil

fertility.

c.

Loss of nutrients- During cutting and burning the trees, the organic matter in the

soil gets destroyed. So the soil becomes poor in nutrient, which makes the farmers

shift to another area.

2. Modern agriculture

This involves the use of hybrid seeds of single crop variety, high-tech equipment,

lot of fertilizer, pesticides and water to produce large amount of single crops.

8/17/2019 Ge6351 Cse Eee It

34/75



Effect of Modern agriculture

1.Fertilizer problem 2. Pesticides problem

3.Water

logging 4.Salinity

a. Micronutrient

imbalance a. First generation pesticides

b. Blue baby syndrome b.

Second generation

pesticides

c. Eutrophication

1.Death of non-target

organism

2.producing new pest

3.Bio-magnification

4. Risk of cancer

1. Fertilizer problem

It is used to improve the soil fertility, fertilizer are used in agriculture.

a. Micronutrient imbalance

Excessive use of fertilizer (N,P,K etc) causes the deficiency of the micronutrient (Zn,

Mn, etc) in the soil which affect the productivity of the soil.

b. Blue baby syndrome

When the nitrogenous fertilizers used in the crop fields is washed off by the runoff

water contaminate the ground water. When the nitrate concentration exceeds 25mg/lit,

they cause serious health problem called blue by syndrome. This disease affects infants

and leads even to death.

c. Eutrophication

When the large proportion of N and P fertilizers used in the crop fields is washed

off by the runoff water and reaches the water bodies causing over nourishment of the

lakes. This process is known as eutrophication.

4. Write the notes on Pesticides problem, Bio-magnification, Water logging and

salinity?

It is used to improve the crop yield, pesticides are used in agriculture

a. First generation pesticides

These are used to kill the pest. For example: sulphur, arsenic, lead, etc

8/17/2019 Ge6351 Cse Eee It

35/75



b. Second generation pesticides

Although these pesticides protect the crops from pests,

they produce number of side effects. There are

1. Death of non-target organism

Many pesticides not only kill the target species, but also kill the several non-target

species, which are useful to us.

2. Producing new pest

Some pest species survive even after the pesticide spray. They are immune to all

type of pesticides and are called superpest.

3. Bio-magnification

Many of the pesticides are non-biodegradable and keep on concentrating in thefood chain. These process is called bio-magnification

Water logging

It is the land where water stand for most of the year. It causes

1. Heavy rain

2. Poor drainage

3. Excessive use of water in agriculture field

Remedy or control1. Preventing excessive irrigation

2. Sub surface drainage technology

3. Bio drainage like Eucalyptus tree plantation

Salinity

The process of accumulation of salts in the top soil is called salinity.

It Causes

1. Irrigation from canal or ground water contains dissolved salts.

2. Evaporation of water, leaving the salts on soil.

Remedy or control

1. Salinity of the soil removed by flushing the good quality water

2. Using sub surface drainage technology .

8/17/2019 Ge6351 Cse Eee It

36/75



5. Discuss about the land degradation?

Soil is no less than our mother as it is indispensable for our survival. It is formed

over long periods of time. But man is degrading it with his misdeeds. Many of our once-fertile soils have already been converted to agriculturally unfit alkaline or saline land or

marshlands. It is estimated that there is more than 25 million hectares of such barren

lands throughout the world. Our soil constitutes a biogeochemical shell around land and

shallow waters. It is a product of the interactions of living matter with rocks. It

profoundly affects the growth of living organism (especially plants) however; in turn it is

influenced by the activities of the latter.

Reasons for Land Degradation

Various factors have led to Land Degradation. Some of them are as under:

1. Rapid increase in industrialization, urbanization and other activities or civilizedman have exercised a tremendous impact on the soils and on other components of the

biosphere.

2. Unplanned destruction of forests and forest litter has brought about serious

changes both in land and water.

3. The washing off of fine soil particles from deforested areas has caused great soil

erosion.

4. Soil erosion has resulted in a great increase in run-off, pollution turbidity and

mineralization in rivers and extensive silting in water reservoirs.

6. What are the types, agents and effects of Soil erosion

Soil erosion is the process of removal of superficial layer of the soil from one

place to another. Soil erosion also removes the soil components and surface liter.

Types of soil erosion

There are two main types of soil erosion

(1) Normal or geologic erosion

This type of soil erosion occurs under normal natural conditions by itself without

any interference of man. It is a very slow process, and equilibrium between loss and build

up is lost, only when there is some major disturbance by a foreign agent.

(2) Accelerated soil erosion

This type of removal of soil is very rapid and never keeps pace with the soil

formation. This is generally caused by an interference of an agency like man and other

animals.

Agents of Soil Erosion

The various agents that bring about soil erosion are as under:-

8/17/2019 Ge6351 Cse Eee It

37/75



Water Erosion

Water removes the soil by falling on as rain drops, a well as by its surface flow action, It

may be of three types

(i) Sheet erosion

Here the removed soil is like a thin covering from large area. This sheet is more or

less uniform.

(ii) Rill erosion

If sheet erosion occurs with full force, the run off water moves rapidly over the

soil surface. It cuts well-defined finger-shaped groove like structures, It appears as thin

channels or streams. These are known as rill erosions.(iii) Gully erosion

This results due to the convergence of several rills or thin channels formed during

rill erosion towards the steep slope. When they join together, they form wider channels of

water, known as gullies. In case of further rains these gullies may become still wider and

deeper.

EFFECTS OF SOIL EROSION

Every year in India, water erosion alone takes away more than 6,000 tonnes of top

soil, containing more than Rs. 1000 crores worth of nutrients. Its evil effects are as under:1. This erosion causes the rapid siltation of tanks and reservoirs.

2. Silt is choking our estuaries and harbors.

3. Eroded soil is deposited on riverbeds, raising their levels and leading to devastating

floods, which cause Rs. 2,000 crores of damage each year.

4. The land area prone to floods has doubled from 20 million hectares in 1971 to 40

million ha. In 1980.

5. Denuded land cannot soak up water like wooded land, so and increasing amount of

rainwater is thus running waste into the sea, causing silting and flooding in the process.

As a result there is much less water stored in underground aquifers, which are vital to

maintain river flower in the dry season and provide water for tube well irrigation.

7. What are the causes and effects of Desertification?

Desertification can be defined as a process of degradations of the environment that

usually is a product of climate and human activity and involves the spread of extension of

desert-like conditions in a hitherto fertile area.

8/17/2019 Ge6351 Cse Eee It

38/75



Causes of Desertification

(1) Man Made

Most of the vegetation in arid and semi-arid regions is threatened with man-madedesertification, a result of excessive, indiscriminate, and archaic land-use practices.

(2) Forest Grazing

Forest grazing is the most serious cause of desertification in arid and semi-arid areas.

(3) Shifting cultivation

Shifting cultivation is likewise important in the humid tropics and N.E. Himalayas.

(4) Increasing Population

Increasing population pressure has greatly accentuated the adverse impacts of the

above causes.

Effects of Desertification

Desertification is usually defined as an irreversible change in a land resource.

Losses are considered irreversible if recovery would take more than a decade. There

forms of desertification can be identified.

1. Loss of economic potential to produce goods and services of direct human-use value;

2. Loss of ecological functions necessary to maintain ecosystem processes;

3. Loss of biodiversity at the ecosystem, species, or genetic level.

According to Nelson (1988):4. A permanent national land monitoring systems is needed to identify emerging and

difficult-to-reverse forms of degradation.

5. Research should focus on management technology and the present socio-economic

systems.

6. Policy proposals must take into account complexity and local variability.

7. In the absence of any global or regional solutions to most savanna and arid land

degradation problems, progress will depend upon small pilot projects, community

experimentation and within-country expertise.

8. It is clear from the failure and high cost of conventional projects that more progress islikely through attention to enabling incentives that promote spontaneous response across

the entire community. The main policy areas are land tenure, taxation and marketing.

9. Many successful strategies will consist of a strong spatial dimension and involve

movement across national and ecological boundaries.

8/17/2019 Ge6351 Cse Eee It

39/75



8. Explain the benefits and problems of timber extraction, dams to the Tribal

people.

It is estimated that India is losing 15 million hectares of forests cover year. If thistrend continuous unchecked, it could take only a period 9 of 20 years hence to reach to

zero forest value in our country. During a period of 25 years (1951-1976) India has lost

4.1 million hectares of forests area. Trees have been felled in large number of fuel,

fodder, valley projects, Industrial uses, road construction etc. India consumes nearly, 170

million tones of firewood annually, and 10-15 million hectares of forests cover is being

stripped every year to meet fuel requirements. The rise in fuel wood consumption can be

noticed from the comparative study of the fuel consumption in earlier years. It was 86.3

million ton in 1953. It reached about 135 million ton in 1980. During a period of 20 years

(1951 to 1971) forests have been cut for various purposes as under:

(1) For Agriculture (24-32 lack hectares)

(2) River valley projects (4.01 lakh hectares)

(3) Industrial uses (1.24 lakh hectares)

(4) Road construction (0.55 lakh hectares)

(5) Miscellaneous uses (3.88 lakh hectares)

In this way, a total of 3.4 million hectares of forests were lost during this period. The

disastrous of the heavy deforestation are visible. Nearly 1 percent of the land surface ofIndia is turning barren every year due to deforestation. In the Himalayan range, the

rainfall has declined from 3 to 4 percent.

Dams

We can classify the environment side effects of river valley and hydel projects into three

categories as under:

(i) Impacts within and around the area covered by the dam and reservoir.

(ii) Downstream effects caused by alternation in hydraulic regime, and

(iii) Regional effects in terms of overall aspects including resources use and

socioeconomic aspects.

The impacts caused by construction of dams and reservoir in including the following

effects and consequences:

(1) The various change in the microclimate.

(2) The loss of vegetal cover.

(3) Soil erosion.

8/17/2019 Ge6351 Cse Eee It

40/75



(4) Enhanced seismic activities due to pressure of water.

It should be kept in mind that the nature and magnitude of the impacts vary with the

project locations and the conditions therein. It can be elucidate with the help ofillustration:

(1) In hilly tracts, blasting operations for road construction can cause considerable

damage to the environment through the following activities:

(a) Loosening of hill sides and resultant landslides,

(b) Sedimentation of reservoirs

(c) Drying up of spring and flash floods.

(2) The creation of new settlements for the workmen and rehabilitation of project out sees

in the watershed areas may result in the aggravation of the seriousness of advanceimpacts. In our country a number of big, medium and minor dams are undertaken mainly

for three purposes-irrigation, power generation and water supply. The country’s first

Prime Minister, Jawharlal Nehru, hailed these dams as the Temples of Modern India.

They have increased agricultural production, power generation and reduced dependence

in imports. However, on the contrary to the advantages enumerated above, some experts

opine that the social, environmental and even economic cost of these dams, far outweighs

their benefits. They hold that the most important social consequences of big dams has

been the displacement of million of tribals from their homeland and their eventual influx

into urban areas, almost as refugees. This is the reason why the scientists,environmentalists, journalists, social activists, lawyers and bureaucrats have now raised

their voice against big dams.

9. Write briefly about the Four Major Projects which has created problems in India.

The four major projects which have generated much controversy are as under:

(i) Sardar Sarovar Project, Gujrat.

(ii) Narmada Sagar Project, M.P.

(iii) Bodhghat Project, M.P.

(iv) Tehri Dam Project in U.P.

Although the above projects have been given environment clearance, struggle is still on

the force of the Govt. to drop these projects. A brief description of these projects and

their possible effects are as under:

1. Sardar Sarovar (SS) Project

This project is near Navagam in Bharuch district of Gujarat. It is one of the costliest

projects affecting villages in three states—M.P., Maharashtra and Gujarat. If it is carried

out, its effects would be as under:

8/17/2019 Ge6351 Cse Eee It

41/75



(i) About 245 villages will be submerged, of which about 193 in M.P. alone.

(ii) Over 75,000 (nearly 50,000 in M.P. alone) people will be evicted.

(iii) Additional displacements is likely to be caused during social and environmentrehabilitation work undertaken to repair the dislocation and damages caused by the

project.

It is evident that compensatory afforestation and setting of wildlife sanctuary will

displace or affect other villagers in the area. The relevancy is evident from the fact that it

has been officially admitted that nearly 43,000 ha of land will be needed for

rehabilitation.

2. Narmada Valley Project (NVP)

It claims to be the world’s largest river valley project. It has attracted the greatest

attention. The 30 big dams and over 3,000 medium and minor dams are envisaged at costof Rs. 25,000 crore. Its effects are anticipated as under:

(i) It would displace over one million people, mostly tribals.

(ii) It would submerge 56,000 ha fertile agriculture land.

(iii) Total forest areas nearly 60,000 ha. will be destroyed.

(iv) Nearly 25 species of birds will be deprived of their habitats.

3. Bodhghat Project

This project is on Indravati river in M.P. The project is in heavily forested Bihar district.

Its effects are anticipated as under:

24 ENVIRONMENTAL SCIENCE(i) The project will destroy teak and sal forests.

(ii) It will spell doom for the last surviving wild buffaloes.

The criticisms of the project forced the Govt. and the World Bank to reconsider it.

4. Tehri Dam

This Dam is proposed on the Bhagirathi river in U.P. at the foothills of Himalayas. It is

Soviet-financed and challenged in the Supreme Court. Its effects are envisaged as under:

(i) This Dam will displace over 85,000 people.

(ii) It will totally immerse the Tehri town and completely or partly submerge nearly 100

villages.

(iii) The site of the Dam is prone to intense seismic activity.

(iv) The 3,200 million ton of water that the Dam would impound could cause a major

earth tempor.

(v) In the event of a disaster, the entire religious townships of Devaprayag, Hardwar and

Rishikesh would be devastated.

(vi) Thousand of hectares of rich, agriculture land will be drowned.

8/17/2019 Ge6351 Cse Eee It

42/75



10. What is FOOD RESOURCES and its types? Explain the world food problems

also

Food is an essential requirement for the human beings. The main components offood are carbohydrates ,fats ,proteins, minerals and vitamins .

Types of food supply

1. Croplands - It mostly produces grains and provide about 76%of the world’s food. E.g.,

Rice, wheat

2.Rangelands - It produces food mainly from the grazinglivestock and provide about 17%

of the world’s food. Ex: Meat, milk, fruits

3.Oceans - Oceanic fisheries supply about 7%of the world’s food, E.g.,: fish, crab

World food problemsReason is only less percentage of the land is cultivated, so the food supplied from the

rest of the land is not enough to feed all the people. The world population explosion

increases and cultivable land area decreases. Therefore the world food problem arises.

1. A key problem is human activity, which degrade most of the earth’s net primary

productivity which supports all life.

2. Urbanization is another problem in developing countries, which deteriorates the

agricultural lands.

3. Environmental degradation like soil erosion, water logging, water pollution,

salinity, affects agricultural lands.4. The food grains like rice, wheat, corn and the vegetable like potato are the

major food for the people all over the world, the food problem arises.

11. Give a brief account of renewable Energy resources and their merits and

demerits?

Energy may be defined as” any property, which can be converted into work”. The

energy resources are available in the following form.

Primary Energy Resources

These resources are available in the form of raw material. These are conventional

as well as non conventional energy resources. Some of these resources are

commercialized as fossil fuels, nuclear fuel, water etc. Some of the non commercialized

resources are solar, wind, agricultural residue etc.

Secondary Energy Resources

These resources are usable forms of energy and may be commercial or non commercial in

nature. These resources are solar energy, wind energy etc.

8/17/2019 Ge6351 Cse Eee It

43/75



Solar energy

The energy that we get directly from the sun is called “solar energy”. Solar collectors are

used to collect the solar energy and convert the incident radiations into thermal energy byabsorbing them. This heat is extracted by flowing fluid (air or water or mixture with

antifreeze) in the tube of the collector for further utilization in different applications. The

collectors are classified as;

• Non concentrating collectors

• Concentrating (focusing) collector

Non Concentrating Collectors

In these collectors the area of collector to intercept the solar radiation is equal to

the absorber plate and has concentration ratio of 1.Concentrating Collectors

Concentrating collector is a device to collect solar energy with high intensity of

solar radiation on the energy absorbing surface. Such collectors use optical system in the

form of reflectors or refractors.

Solar Air Heaters

Air stream is heated by the back side of the collector plate in flat plate collector.

Fins attached to the plate increase the contact surface. The back side of the collector is

heavily insulated with mineral wool or some other material. If the size of collector islarge, a blower is used to draw air into the collector and transmit the hot air to dryer.

The most favourable orientation of a collector for heating only is facing due

south at an inclination angle to the horizontal equal to the latitude plus 150. The use

of air as the heat transport fluid eliminates both freezing and corrosion problems and

small air leaks are of less concern than water leaks.

8/17/2019 Ge6351 Cse Eee It

44/75



Disadvantages:

1. Need of handling larger volumes of air than liquids due to low density of air as

working substance.2. Thermal capacity of the air is low.

3. They have relatively high fluid circulation costs (especially if the rock heatstorage

unit is not carefully designed)

4. They have relatively large volumes of storage (roughly three times as much

volume as for water heat-storage)

Solar Cooker

Though there are many types of solar cookers, all of them have a concentrator

or lenses to increase the available solar energy and insulation to reduce heat loss.There is an oven type cavity to place food into the box for cooking. Solar cookers are

commonly able to reach cooking temperatures of 90-1500C and some can even reach

2300C. With these temperatures, it is possible to cook virtually any food as long as it is

sunny outside.

Solar Ponds

The solar pond is a simple device for collecting and storing solar heat. Natural

ponds convert solar radiation into heat, but the heat is quickly lost through convection

in the pond and evaporation from its surface. A solar pond, on the other hand, is designedto reduce convective and evaporative heat losses so that useful amounts of heat can be

collected and stored.

The direct way of using solar energy are

(i) Solar thermal technology through solar collectors

(ii) Photo voltaic energy conversion technology

(iii) Solar hydrogen gas production technology.

8/17/2019 Ge6351 Cse Eee It

45/75



The indirect way of using solar energy are

(i) Wind energy through wind mills

(ii) Biomass through energy plantation(iii) Biogas through Biogas plants

(iv) Tidal wave energy.

Applications of Solar energy:

1. Heating and Cooling of buildings

2. Solar cookers

3. Electricity generation through Photo voltaic cells

4. Solar furnaces

Wind Energy

Wind results from air in motion. Energy recovered from the force of the wind is called as

“wind energy”

WIND MILLS

The strike of blowing wind on the blades mill of the wind mill make it rotating

continuously. The rotational motion of the blade drives a number of machines like water

pump, flour mills and electric generators.

8/17/2019 Ge6351 Cse Eee It

46/75



Wind farms

When a large number of wind mills are installed and joined together in a define pattern

it farms a wind farm. The wind farms produce a large amount of electricity.Condition

The minimum speed required for satisfactory working of wind generator is 15 km/hr.

Advantages of Wind Energy

1. It is renewable source of energy

2. Now polluting and no adverse influences on environment.

3. No fuel and no transportation is required

4. The cost of electricity production is comparatively low

Disadvantages1. Wind energy is dilute and fluctuating in nature

2. It requires storage capacity

3. Machines operating on wind energy are noisy

4. Wind power machines are relatively have high overall weight (110 kg/kw)

5. large area is required

6. Efficiency of operation is poor and maintenance costs are high

Bio – Diesel

Bio diesel is a vegetable oil processed to resemble diesel fuel.Importance of Bio diesel:

1. Environment friendly

2. Clean burning

3. Renewable fuel

4. No Engine modification

5. Increase engine life

6. Easy to handle and store.

8/17/2019 Ge6351 Cse Eee It

47/75



UNIT IV– SOCIAL ISSUES AND THE ENVIRONMENT

1. State the declaration about the sustainable development.The Rio declaration states that, “human beings are at the center or concern for

sustainable development. They are entitled to a healthy and productive life in harmony

with the nature. Every generation should leave air. Water and soil resources without any

pollution as pure as it came to the Earth.”

2. Define sustainable development.

Sustainable development is defined as meeting the needs of the preset without

compromising the ability of future generations to meet their own needs.

3. What are the three important components of sustainable development?

The three important components of sustainable development are

1. Economic development (like industrial development, creating job opportunities,

utilization of natural resources for developing the quality of life)

2. Community development (providing food, shelter, cloth, education, and other

essentials for the human beings).

3. Environmental protection (providing clear air, water and environment for the

present and future generations and utilization of resources in a susta

Documents

Ge6351 Cse Eee It