✍️Notes on Environmental Chemistry:

🔹Components of Environment:

➖Atmosphere: This comprises a blanket of gaseous layer around earth.

➖Hydrosphere: This comprises about 96% of earth’s surface & includes all sources of water like oceans rivers lakes, glaciers, ground water etc.

➖Lithosphere: It refers to earth’s solid crust containing the outer mineral cover. It comprises soil, minerals, organic matter etc.

➖ Biosphere: It refers to the domain of living organism in covalent with atmosphere hydrosphere as well as lithosphere.

🔹Environmental Pollution :
Process of contamination of the environment with harmful wastes arising mainly from human activities.

➖Pollutant: Any substance or species produced either by a natural source or by human activity, which produces adverse effect on the environment.

➖Contaminant: A substance which does not occurs in nature but is introduced by human activity into the atmosphere affecting its composition.

➖Source: The site from which the pollution or contaminants originate.

➖Sink: The material or medium which consumes or interacts with a long lived pollutant is called sink.

➖Receptor : Anything that is affected by the pollutants.

➖Threshold limit value (TLV) : This indicates the permissible limit of a pollutant in atmosphere to which a healthy worker is exposed during hours a day or 40 hours a week for life time without any adverse effects. TLV are determined by experimentation on animals, by use of medical knowledge, epidemiology surveys & environmental studies.

🔹Tropospheric pollution or Air pollution:
It is the atmosphere condition in which the presence of certain concentration produce harmful effects on man and his environment. These substances include:

(i) Gases such as oxides of sulphur, CO, oxide of N2 and hydrocarbons

(ii) Particulate matter such as dust, smoke, fumes etc.

(iii) Radioactive material & many others.

➖Primary pollutants : These are the pollutants which are emitted directly from the sources. Some examples are:

➖Particulate Matter : Such as ash, smoke, dust, fumes etc.

➖Inorganic gases : Such as sulphur dioxide, carbon monoxide etc.


🔹Particulate matter:

➖Soot: produced by incomplete combustion of carbonaceous fossils fuels such as coal, fuel oil, natural gas, wood etc in insufficient supply of oxygen.

➖Metal particles: These are released by various metal finishing operation. The micro particles of toxic metal & SO2 gas present in the polluted atmosphere get absorbed on the particles rendering them highly toxic.

➖Metal oxides : They are generated by combustion of fuels containing metallic compounds.

➖Lead salts: Their source is lead tetraethyl (Pb(C2H5)4) which is added to gasoline to improve its antiknock property. In order to avoid deposition of PbO suitable amounts of C2H4Cl2 & C2H4Br2 are added to gasoline along with Pb(C2H5)4.

➖Fly ash: It originates from the combustion of high ash fossil. It contains partially burnt particles of the fuels.

➖Asbestos dust: It originates from industrial units manufacturing asbestos sheets, gaskets ropes etc. Asbestos flowing & asbestos insulations also contribute towards asbestos dust in the atmosphere.

➖Solid Hydrocarbons: These are emitted from petroleum refineries & comprise of paraffins, olefins & aromatics.

➖Dust Particulates: Originate from natural, domestic, industrial or agricultural sources. These are thrown into atmosphere by volcanic eruptions, blowing of dust by wind, mining operations etc.

➖Acid mist : Sulphuric acid mist is produced when SO3 present in the atmosphere comes in contact with moisture. Nitric acid mist is produced when oxides of nitrogen, viz, NO & NO2, undergo the series of reactions in the atmosphere.

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ℙ𝕝𝕒𝕟𝕔𝕜'𝕤 ℚ𝕦𝕒𝕟𝕥𝕦𝕞 𝕋𝕙𝕖𝕠𝕣𝕪
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❖ Substances that absorb or emit light discontinuously in the form of small packets or bundles.

❖ The smallest packet of energy is called quantum (plural quanta).

❖ The radiation is propagated in the form of waves.

❖ The energy of a quantum is directly proportional to the frequency of the radiation

E ∝ v
E = hv
E = (hc)/ λ =hc v

Where E = Energy of radiation
h = Planck's constant
= 6.626 * 10^-27 * erg .sec
= 6.626 * 10^-34 Joule.sec

❖ A body that can absorb or emit energy in whole number multiple of quantum.

E = nhv

Where n = 1, 2, 3, 4

❖ The frequency of emitted radiation goes from lower to higher as the temperature increases.

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IMPORTANT Years In NCERT :-

1731 - Many people of Bishnoi community sacrifice their lives saving trees (Jodhpur)

1770 - Priestley's experiment by Bell Jar, Mice & Mint plant, Candle.

1774 - Discovery of oxygen by Joseph Priestley

1838 - Matthias Schleiden-Cell Theory                                                   

1829 - Theodore Schwann- Cell Theory

1850s -  Before industrialization => more white wing Moth

1854 - Julius von Sachs proved that glucose is formed in photosynthesis & stored as starch.

1855 - "Omnis cellula cellula" by Rudolf Virchow & complete the cell theory.

1856 - 1863 Mendel work on garden pea.

1860 - Hydroponics technique developed by Julie Von Sache

1865 - Mendel publishes his workon inheritance of character

1866 - Down's Syndrome discovered by Langdon Down.

1869 - DNA as a acidic substance was 1st identified by Friedrich Meischer & termed a "Nuclein"

1891 - Fossils of Java man discovered in Java
          - Henking discovered X-body (X-chromosome) in insect. (XO- type sex determination)

1892 - Discovery of TMV by D.J. Ivanowsky

1898 -  M.W. Beijerinck demonstrated infectious nature of TMV
          - Discovery of Golgi Body by Camillo Golgi.

1900 - Rediscovery of Mendel's work by ---> • Hugo de Vries
           • Karl Corrence
           • Tschemark

1902 - Chromosomal theory of inheritance given by Sutton & Bovery.

1905 - Law of limiting factors for plants given by Blackmann

1920 - After Industrialisation => more black moth

1928 - Frederick Griffith's Transformation  experiment on Streptococcus pneumonia bacteria

1933 – 1944 - Avery, Macleod McCarty used transformation principle of Griffith's experiment & concluded that DNA is genetic material.

1938 - Coelacanth/Lobe Fines caught in South Africa ---> Ancestor of amphibia.

1947 - At the time of our independence India's population, was approximately 350 million .

1950 -  Electron microscope invention
            -  Tissue culture started

1951 - Family planning was initiated

1952 - Hershey & Chase experiment more correctly proved that DNA ie genetic material [ unquivocal_proof ]

1953  - Discovery of ribosome by George Palade.
          - S.L Miller Experiment of evolution.
          - Double helical structure model of DNA given by Watson & Crick.

1958 - Matthew Meselson of Franklin Stahl experiment (E. coli in NH4CI medium) proved that DNA replication is semiconservative )
         -  Taylor study on vicia faba plant (used radioactive thymidind and proved  semiconservative nature of DNA)

1960 -  Green Revolution.

1963 - Restriction endonuclease isolated from E. coli.

1963 - Wheat varieties Sonalika f Kalyan Sona (High yield & Disease resistant ) introduced in INDIA

1966 - Derived semi dwarf varieties of rice introduced in India.

1969 - R.H. Whittaker proposed FIVE-KINGDOM Classification

1971 - Discovery of viroids by T.O. Diener
          -  Govt. of India legalised MTP.

1972 - Fluid Mosaic model of plasma membrane by Singer & Nicolson
          - 1st recombinant DNA developed by Stanley Cohen and Herbert Boyer
          - National committee for environmental planning and Coordination was established.
          - Wild life protection act in India.

1974 -  Water Act.  &  also Chipko movement

1980 -  Joint Forest movement

1981 - Air act.
           - AIDS was fired reported
           - Intrinsic growth rate of India (r= 0.0205) 

1983 - Eli Lilly American company human Insulin from E. coli.

1984 - Bhopal Tragedy
          - Ministry of Environment amd Forest.

1986 - Environment Act (NEPA)

1987 - Noise included in air pollution  
          - Montreal protocol (Canada)

1988 - National Forest Policy

1989 -  Montreal Protocol became effective.

1990 -  Delhi ranked 4th among 41 most polluted cities.

1990 - First clinical gene therapy was given to 14 yr old girl with ADA deficiency eye.
- Human Genome Project (HGP) launched.