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TitleBasics of Environment and Ecology
TagsEcosystem Natural Environment Environmentalism Food Web
File Size12.2 MB
Total Pages156
Table of Contents
                            Preface
Contents
Chapter 1 Environment and Ecology
	1.1 Introduction
	1.2 Scope
	1.3 Importance of Environment
	1.4 Need for Public Awareness
	1.5 Concept of Ecology and Ecosystem
	1.6 Balanced Ecosystem
Chapter 2 Human Impacts on Environment
	2.1 Introduction
	2.2 Major Aspects of Human Activities
	2.3 Effects of Human Activities on Environment
Chapter 3 Environmental Impact Assessment and Sustainable Development
	3.1 Introduction
	3.2 Environmental Impact Assessment (EIA)
	3.3 Sustainable Development
Chapter 4 Natural Resources
	4.1 Water Resources
	4.2 Availability and Quality Aspects
	4.3 Water Borne and Water Induced Diseases
	4.4 Fluoride Problem in Drinking Water
	4.5 Mineral Resources
	4.6 Forest Wealth
	4.7 Material Cycles
Chapter 5 Energy
	5.1 Introduction
	5.2 Types of Energy Resources
	5.3 Electromagnetic Radiations
	5.4 Conventional Energy Resources (Fossil Fuel Based)
	5.5 Non-Conventional Energy Sources
Chapter 6 Environmental Pollution
	6.1 Water Pollution
	6.2 Land Pollution
	6.3 Noise Pollution
	6.4 Public Health Aspects
	6.5 Air Pollution
	6.6 Solid Waste Management
Chapter 7 Current Environmental Issues of Importance
	7.1 Population Growth
	7.2 Climate Change
	7.3 Global Warming
	7.4 Acid Rain
	7.5 Ozone Layer Depletion
	7.6 Urbanization
	7.7 Automobile Pollution
	7.8 Animal Husbandry
Chapter 8 Environmental Protection
	8.1 Role of Government
	8.2 Legal Aspects
	8.3 Initiatives by Non-Governmental Organizations
	8.4 Environmental Education
	8.5 Women Education
Suggested Readings
Glossary
Index
                        
Document Text Contents
Page 78

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Biofuels can be obtained by fermenting biomass that produces alcohols like ethanol and methanol.
Ethanol can be easily produced from carbohydrate rich substances like sugarcane, corn and sorghum
(Jowar). It burns clean and is non-polluting. However, as compared to petrol its calorific value is less
and therefore, produces much less heat than petrol. It is also considered to be an excellent substitute for
kerosene and its combustion is as clean as LPG. Ethanol is obtained from grain-based or sugar-containing
plants like maize, cereals or even organic wastes.

Methanol is very useful since it burns at a lower temperature than gasoline or diesel. Thus the
bulky radiator may be substituted by sleek designs in our cars. Methanol too is a clean, non-polluting
fuel. Methanol can be easily obtained from woody plants.

Gasohol is a common fuel used in Brazil and Zimbabwe for running cars and buses. In India too
gasohol is planned to be used on trial basis in some parts of the country, to start with in Kanpur. Gasohol
is a mixture of ethanol and gasoline.

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As hydrogen burns in air, it combines with oxygen to form water and a large amount of energy (150
kilojoules per gram) is released. Due to its high, rather the highest calorific value, hydrogen can serve
as an excellent fuel. Moreover, it is non-polluting and can be easily produced.

Production of hydrogen is possible by thermal dissociation, photolysis or electrolysis of water:

(i) By thermal dissociation of water (at 3000 K or above) hydrogen (H2) is produced.

(ii) Thermochemically, hydrogen is produced by chemical reaction of water with some other
chemicals in 2–3 cycles so that we do not need the high temperatures as in direct thermal method and
ultimately H2 is produced.

(iii) Electrolytic method dissociates water into hydrogen (H2) and oxygen by making a current
flow through it.

Page 79

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(iv) Photolysis of water involves breakdown of water in the presence of sunlight to release
hydrogen. Green plants and micro-algae also carry out photolysis of water during photosynthesis. Efforts
are underway to trap the hydrogen molecule which is produced during photosynthesis. Hydrogen
generated by microbial systems is called biohydrogens.

However, hydrogen is highly inflammable and explosive in nature. Hence, safe handling is
required for using H2 as a fuel. Also, it is difficult to store and transport. And being very light, it would
have to be stored in bulk.

Presently, H2 is used in the form of liquid hydrogen as a fuel in spaceships. H2 can be used in
fuel cell to generate electricity. In fuel cell hydrogen is burnt in air or oxygen in the pressure of an
electrolyte to produce electricity.

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1. What are renewable and non-renewable resources? Give examples.
2. Give an account of non-renewable energy resources?
3. What are electromagnetic radiations? What are the anthropogenic sources of these radiations?
4. Discuss properties of electromagnetic radiations.
5. What are solar cells? Draw a diagram of a solar cell and enumerate its applications.
6. What is biogas? Discuss the structure and function of biogas plants.
7. What is nuclear energy? Discuss its two types.
8. What is hydro-electric energy? How is it generated?
9. Can hydrogen be used as a fuel? How can hydrogen be produced?

10. Discuss various benefits of using hydrogen as a fuel.

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(A) FILL IN THE BLANKS

1. ......... resources are inexhaustible resources which can be generated within a given span of time.
2. ......... resources can not be generated.
3. ........., ......... and ......... are the natural sources of electromagnetic radiations.
4. ........., ......... and ......... are man made sources of electromagnetic radiations.
5. .........is the most abundant fossil fuel in the world.
6. ........., ......... and ......... are conventional sources of energy.
7. Natural gas has high calorific value of about ......... kJ/g.
8. Biogas is produced by ......... degradation (in the absence of oxygen) of biological wastes.
9. 95% natural gas is .........

10. Gasohol is a mixture of ......... and .........

Page 155


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Pesticide 18

Petroleum 60

Photovoltaic cells 64

Point sources 72

Poliomyelitis 43

Poliovirus 43

Pollution

air 74-77

land 66-68

nose 68-71

water 62-66

Pollution moderators 51

Population

characteristics of 82-85

explosion 97

growth 93

stabilization 99

Positive feedback mechanisms 10

Primary pollutants 84

Producers 8

Public health aspects 82

Public water supply 82

Putrefaction 83

Pyramid shaped 94

Pyrolysis 67



Recharge of springs 51

Recycling of materials 89

Renewable resources 58

Replacement level 94

Resource depletion 21



Salinity 19

Salinity problem 19

Salinization and waterlogging 20

Salmonella typhi 43

Sanitary landfill 89

Schistosomiasis, ancylostomiasis, dracunculiasis 44

Scoping 31

Screening 31

Secondary pollutants 84

Sedimentary cycle 52

Sewerage and sewage disposal 83

Shelter 15

Shifting cultivation 16

Shigella dysenteriae 43

Skeletal fluorosis 46

Slash and burn cultivation 16

Slash and burn cultivation or shifting cultivation 16

Social security 16

Soil conservation 51

Soil erosion 17, 51

Soil moisture 39

Solar cells 64

Solar cooker 66

Solar energy 64

Solar furnace 67

Solar heat collectors 64

Solar power plant 67

Solar water heater 67

Solid wastes 88

effects of 78

management 79, 80

sources of 78

State pollution control boards 119

Strategic minerals 50

Strip mining in 23

Sub-surface mining 22

Subsidence 39

Subsidence of land 23

Sulphur cycle 54

Super pests 18

Supporting capacity 34

Page 156

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Surface mining 22, 23

Surface water 39

Surface water pollution 24

Sustainable development 28, 32

Swamps and marshes 39

Synthetic natural gas (SNG) 62



Tehri bachao andolan 6

The air (prevention and control of pollution) act, 120

The air (prevention and control of pollution) act, 120

The environment (protection) act, 1986 120

The state pollution control boards 119

Thiobacillus ferroxidans 24

Total fertility rates 94

Total fertility rates 94

Traditional agriculture 17

Traditional agriculture and its impacts 17

Transportation 25

Tropical forests 51

Typhoid 43



UN Conference on environment and development
(UNCED) 33

UN World summit on sustainable develpment (WSSD)
33

Unconfined aquifers 38

Undernourished 15

Urban and industrial wastes 88

Urban heat island 109

Urbanization 108

Urn shaped 95



Vibrio cholerae 43



Wangari Maathai 5

Water (prevention and control of pollution) act, 1, 118

Water availability 37

Water logging 19, 39

Water pollution 72, 118

Water quality 40

Water resources 37

Water table 39

Waterlogging 19

Watersheds 51

Wildlife habitat 51, 61

Wildlife (protection) act 116

Wind-breaks 51

Women education 125

World environment day 115



Zero population growth 96

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