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Glossary

A

Abiotic: The non-living component such as light, humidity, temperature etc.

Acid Rain: The pouring down of acidic secondary pollutants such as HNO3 and H2SO4 along with rainfall.

Aerosols: Particles having diameter less than 10 μm.

Agrochemicals: The chemicals such as fertilizers, pesticides etc. which are used in agriculture.

Air Pollution: The presence of contaminants such as CO, SO2, solids and other particles in air.

Albedo: The reflecting capacity of earth.

Alkalinity: The total amount of substances which increase the concentration Ofhydroxide ions.

Atmosphere: The cover of air that surrounds the earth. It is a mixture of several gases such as nitrogen, oxygen, carbon dioxide etc.

B

Bio-Geo Chemical cycle: The circulation of nutrients between environmentandorganisms.

Biomass: Organic matter derived from plants materials, animal waste and other wastes generated by timber industry, agricultural crops etc.

Biome: Smaller divisions of the biosphere which are characterized by a typical climate, vegetation, soil and animal life.

Biosphere: Region comprising of Uthosphere, hydrosphere and atmosphere where living organisms can exist.

Biotic: The Uving components such as plant, animals and micro-organisms. BOD (Biological Oxygen Demand): Measure of amount of oxygen which is needed by the micro-organism and inorganic pollution load in polluted water.

C

• Carcinogen: Cancer causing agent.

• Chemical Oxygen Demand: Measure of amount of oxygen required to breakdown the organic matter by chemical oxidizing agents.

• Climate: The long term average weather conditions over a period of time for a given place.

• Consumers: The heterotrophs which depend on other organisms for food.

D

• Decomposers: Micro-organisms which decompose the dead bodies into smaller compounds.

E

• Ecosystem: An environmental system comprising a biotic community and its abiotic components.

• Environment: The sum total of all living and non-living surroundings.

• Eutrophication: The highly productive state of water bodies due to excess of nutrients.

F

• Fossil fuels: Fuels formed from the incomplete biological decomposition of dead organic matter such as plants and marine organisms.

• Fuel cells: Device to produce electricity by combination of fuel and oxygen by an electrochemical reaction.

• Fungi: Plants without chlorophyll. They are parasitic in nature as they cannot make their own food.

• Fungicides: Chemicals which inhibit the growth of fungi by fungal diseases.

• Global Warming: Increase in the average temperature of earth’s atmosphere due to Green House effect.

• Green Chemistry: The chemistry of environmentally benign prod­ucts and processes.

• Green House Effect: The phenomenon of trapping the heat from the Sun into the Earths atmosphere without letting it escape. Responsible for making the temperature of atmosphere comfortable for living.

• Ground Water: The water below the water table where saturation condition exist.

H

• Hard Water: Water that forms an insoluble scum on addition of soap or boiling.

• Hazardous Waste: The dangerous wastes which is corrosive, toxic, reactive and ignitable.

• Herbicides: Chemicals which kill unwanted weeds or interfere with their growth. Examples: pentachlorophenol, 2,4,5-T, 2,4-D etc.

• Humus: The organic matter obtained from dead animal and plants.

• Hydrocarbons: Compounds containing carbon and hydrogen.

• Hydrosphere: All water bodies on the earth such as ocean, seas, rivers.

I

• Incineration: Controlled combustion of waste for completely oxidizing it and destroying harmful micro organism present in it.

• Insecticides: The chemicals which are used for controlling or eliminating insect pests.

• Ionosphere: Region of atmosphere between altitude of 50-100 km.

L

• Lapse Rate: The change in temperature with distance in troposphere.

• Liming: The treatment of calcium deficient soil with lime.

• Lithosphere: The uppermost layer of the surface of earth up to 400 km.

M

• Macro-nutrients: The elements required in large amounts such as carbon, nitrogen, oxygen, phosphorus etc.

• Mesosphere: The low temperature region above mesosphere which extends up to an altitude of 90 km.

• Micelle: The aggregation formed in the presence of surfactant which help in removing oil and grease particle by dissolving them.

• Micro-nutrients: The elements required in small or trace amounts such as sodium, cobalt, chlorine, fluorine etc.

• Municipal Waste: The total spent water including sewage of the Connnunity flowing through a sewer.

N

• Nitrogen Fixation: Conversion of atmospheric nitrogen to usable forms such as nitrates or ammonia by various chemical processes.

• Nuclear Fission: splitting of atomic nucleus into smaller fragments.

• Nuclear Fusion: combining of smaller atomic nuclei to form heavier nucleus.

O

• Ozone Hole: The thinning of ozone layer of the atmosphere.

P

• Particulates: Finely divided suspended solid particles in the atmosphere.

• Permanent Hardness: It is caused by the presence of chlorides and sulphates of Ca, Mg or any other heavy metals.

• Photochepiical Smog: The combination of smoke, dust and fog with air pollutants such as oxides of nitrogen and hydrocarbons.

• Pollution: The presence of harmful substances in the environment which degrades its quality and causes adverse effects.

• Polymer: Macromolecule formed by the combination of smaller units called monomers.

• Preservatives: The agents used for preventing the undesirable changes caused-by bacteria, yeast etc.

• Primary Particulates: Particulates having 1-20 μm diameter which are directly injected into the air. Examples: pollens, coal dust, cement dust, fly ash etc.

• Primary Pollutant: Pollutant formed as a result of natural phenomenon or other activities which enters directly into the environment.

Examples CO, SO2, hydrocarbons etc.

• Producers: The autotrophs which synthesize their own food from simple substances such as CO2 and water in presence of sunlight. Examples: Green plants, certain bacteria and algae.

• Putrefaction: Rottening of organic matter (with bacteria and fungi).

R

• Radioisotope: The radioactive isotope of an element which spontaneously undergo radioactive decay by the emission of radiations.

• Radioactive Fallout: The radioactive dust falling on the earth after nuclear explosions.

• Rain Water Harvesting: The process of augmenting the natural infiltration of rain water or surface runoff into the ground by artificial methods.

• Reforming: The process of heating gasoline at high temperature and pressure to increase the octane number. It may involve isomerisation, dehydration, aromatization etc.

S

• Scrubbing: Treatment of gases obtained after combustion of coal with CaCO3 to remove SO2.

• Secondary Particulates: Particulates formed from primary particulates. They are formed by combustion processes and vehicular emissions and are responsible for photochemical smog.

• Secondary Pollutant: They are formed from primary pollutants by their further reaction. Example SO3, NO etc.

• Sewage: The combined liquid waste discharged from domestic and industrial sources.

• Smog: Smoke + Fog

• Soft Water: Water which lathers easily with soap.

• Soil: The complex mixture of different types of materials derived from the rocks, organic matter and other materials.

• Stratosphere: The region above troposphere extending up to an altitude of about 50 km.

• Surfactants: The substances which lower the surface tension of water and help in dispersing the soil or dirt particles.

• Sustainable Development: Development which meets the needs of the present without compromising the ability of future generations to meet their needs.

T

• Temporary Hardness: Hardness due to bicarbonates of Ca and Mg.

• Total Solids: Amount of non-volatile substances present in water in a colloidal and molecular dispersed state.

• Transpiration: Loss of water from leaves of the plants via evaporation.

W

• Weathering: Crumbling and wearing away of rocks.

• Wet lands: The lands which are transitional between terrestrial and aquatic systems.

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Source: Ahluwalia V. (ed.). Malhotra S. (ed.) Environmental Science. CRC Press,2007. — 368p.. 2007

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