Air pollution and control with composition of structure of atmosphere, classification of pollutants and sources of pollutants and their unit of measurement.
2. AIR POLLUTION
Definition:-
• Air pollution is the presence in the outdoor
atmosphere of one or more air contaminants
in sufficient quantities, of such characteristics,
and of such duration as to be or to threaten to
be injurious to human, plant or animal life or
to property, or which reasonably interferes
with the comfortable enjoyment of life or
property.
5. SOME FACTS…..SHOULD BE
KNOWN• Ozone layer in stratosphere is being depleted.
• The amount of tropospheric CO2 is increasing at the rate
of 1.8mg/m3 (the process is not reversible)
• There is an equivalent decrease in atmospheric O2.
• There are more than 700 billions tones of carbon in the
form CO2 of in the atmosphere.
• Each year the fig. is increases by 2.3 billions tones.(@3%
increase per decade.)
• Temperature of earth is increasing.
6. UNITS OF MEASUREMENT
• Particulate fallouts or dustfall……..
Milligram per square centimeter per unit time.
i.e. mg/cm2/year.
• In particulate counting……
No of particle per cubic meter of gas i.e. 106/m3.
• Measurement of suspended particulate and the
gaseous pollutants……
Microgram per cubic meter. i.e. µg/m3.
• Most popular unit to express concentration is parts
per million(ppm)
8. CLASSIFICATION OF POLLUTANTS
Primary classification……
Natural contaminants
Anthropogenic contaminants
According to origin……
Primary pollutants….SOx, NOx, HC
Secondary pollutants…O3, PAN(paroxyacetyl nitrate)
According to chemical composition……
Organic …… HC, alcohols, ethers
Inorganic……CO, CO2, SOx, NOx
According to State of matter……
Particulate pollutants
Gaseous pollutants