Concept and scope of environmental chemistry.pptx

1. Nashik District Maratha Vidya Prasark Samaj’s
Arts, Commerce and Science College,
Tryambakeshwar
Department of Chemistry
Class: T.Y.B.Sc.
Subject: Environmental & Green Chemistry
(CH-336D) Sem-III First term
Presented by
Rhushikesh Pandit Gotarne (M. Sc., SET)

2. Chapter - 1
Concepts and Scope
Of
Environmental Chemistry

3. Contents
1. Concepts and scope of Environmental Chemistry
2. Segments of Environment- Atmosphere, Hydrosphere, Lithosphere,
Biosphere
3. Termiology- Pollutant, Contaminat, Source, Receptor, Sink, Pathways of
pollutant, Speciation, D.O., C.O.D., B.O.D.,T.L.V., Residence time
4. Units of concentration

4. What is Environmental chemistry?
• Environmental Chemistry is branch of chemistry
• Study of the sources, reactions, transports and effects also fates of
chemical species (atoms, molecules, ions, etc.) in water, soil, air and the
living environmental and the effect of human activity upon these
• Study of physical and chemical processes occurring in environment
which are impacted by humankind’s activities

5. Environment
• The word environment originates from French root ‘environner’ it means
“ to surrounding”
• It means that the surrounding that surrounds living beings from all sides
and affect their lives
• Disturbance of environment due to- Industrial revolution, advancement in
technology, tremendous population rise

6. Environmental Calamities
• Mercury poisoning from contaminated sea food (Japan,1953)
• Recurrence of killer smog (London, 1952 & 1957)
• TCCD incident (Italy,1976)
• Bhopal disaster (India, 1984)

7. Segments of Environment
• 1. Atmosphere
• 2. Hydrosphere
• 3. Lithosphere
• 4. Biosphere

8. 1. Atmosphere
• Protective blanket of gases surrounding the earth
• Absorbs most of the cosmic rays & EMR from the sun
• U.V. radiations (λ < 300 nm) absorbed by atmosphere
• Source of gases- O2 (aerobic life)
CO2(photosynthesis & nitrogen fixation)

9. 2. Hydrosphere
• This comprises of all the surface and ground water resources such as
seas, oceans, lakes, streams, glaciers, polar ice caps etc.
• Oceans- 97% salty water
• Polar ice caps and glaciers- 2%
• Fresh water- 1%
• Fresh water uses- Irrigation(~30%), Thermal power plants (~50%),
Industrial Consumption (~12%) and Domestic (~7%)

10. 3. Lithosphere
• It is the outer cover of solid earth; consisting of the soil and rocks
• Soil is made up of organic, inorganic matter (minerals), air and water
• They are responsible for the fertility of soil and hence its productivity
• Solid wastes produced from industrial, mining, agricultural and houshold
activities pollutes the lithosphere

11. 4. Biosphere
• It is the part of Earth where life exists
• It denotes living organism and their interactions with other three
segments viz., earth’s crust, atmosphere and hydrosphere.
• Biosphere forming in the zone of about 600 m above and 10,000 m below
sea level
• Survival of biosphere depends the availability of various essential elements
in other three segments of environment

12. Terminology

13. 1. Pollutants
• Anything in the environment, living or non-living or any physical agent (such
as noise, heat) that is found above certain level such that it is injurious to
human, plant or animal life is called

14. Units of concentration
• Concentration of pollutants- conventionally expressed as fractions
• ppm - parts per million
• pphm - parts per hundred million
• ppb - parts per billion
• ppt - parts per trillion
• 1 ppm ≡ 0.0001% ≡ 100 pphm ≡ 1000 ppb ≡ 1000000 ppt

15. Units of concentration
• In case of liquid and solid samples – parts by weight
• Conventionally quantity of water is expressed in litres, So conversion of
litre to gram required
• 1 L water≡ 103 mL water ≡ 103 g of water ≡ 106 mg water
• eg. 4 ppm D.O. ≡ 4 mg D.O. per 106 mg of water
≡ 4 mg D. O. per 1 L water

16. Units of concentration
• In case of gaseous samples – volume
• 1 ppm of NO2 in air means 1 volume of NO2 per 106 volume of air
• According to Avogadro’s principle – number of molecules/moles of
gases are proportional to their volumes under same condition
• So, ppm unit for gaseous sample refers to number of molecules/moles of
gas per million molecules/moles of air

17. Units of concentration
• When conc. of concerned species is extremely low then use another unit -
Number of molecules per unit volume (cm3)of air
• So, ppm unit refers to number of air molecules in 1 cm3 air
• Another unit used to show conc. of gaseous samples – mass per unit
volume
• Usually, microgram per cubic meter of air (μg/ m3)