Environmental Engineering and Science (HS103C) Lecture 6 PDF

Environmental Engineering and Science (HS103C) Dr. JYOTI KAINTHOLA Air Pollution Air Pollution Definition:- Air pollution is defined as “ Excessive concentration of foreign matter in air, which adversely affects the well being of individuals or causes damage to the proper...

Environmental Engineering and Science (HS103C) Dr. JYOTI KAINTHOLA Air Pollution Air Pollution Definition:- Air pollution is defined as “ Excessive concentration of foreign matter in air, which adversely affects the well being of individuals or causes damage to the property”. Composition of Air Major Sources of Air Pollution Major Sources of Air Pollution Natural Sources:- The natural sources of air pollution are volcanic eruptions releasing of poisonous gases like SO2 ( Sulfur dioxide), Hydrogen sulphide (H2S), Carbon Monoxide(CO), Forest fires, natural organic and inorganic decays, Pollen grains, wind blown dust, among them pollen grain are important because it causes allergic reactions in individuals.  Anthropogenic Sources Rapid Industrialization:- The Industries such as pulp and paper, chemical, metallurgical plants, refineries are responsible for air pollution, the most common pollutants are CO2, SO2, CO, NO, H2S etc. Transportation:- Automobile exhausts release smoke. The smoke is a result of incomplete combustion of carbonaceous matter. The common pollutants are CO ( Carbon Monoxide), CO2, and Hydrocarbons.  Burning of Fossil fuels and fires:- The conventional sources of energy are wood, coal, and fossil fuels. The byproducts of fossil fuels is nothing but poisonous gases such as CO, CH4 (methane), SO2, and NOX. Deforestation:- The balance of O2 and CO2 is maintained in the nature by the vegetation. The deforestation by man for his own needs has disturbed the balance of CO2 and O2, Concentration.  Increase in Population:- an increase in population leads to global warming and emission of green house gases. It also contributes to losses in forest cover and loss of wild life. Agriculture activities:- Various pesticides and insecticides are used for agricultural purposes. Thus they cause air pollution. Radioactive fallout:- Nuclear reaction, nuclear weapon testing contributes towards Nuclear pollution. Nuclear Pollutants are very harmful to man, animals and vegetations. According to Origin Air Pollutants can be classified as (a) Primary Pollutants (b) Secondary Pollutants Primary Pollutants:- Primary pollutants are those which are directly emitted from identifiable source These pollutants are emitted directly to the atmosphere. (a) Particulate matter (b) Oxides of Sulphur (c) Oxides of Nitrogen (d) Carbon Monoxide (e) Radioactive Compounds  Secondary Air Pollutants:- Secondary air pollutants are those which are produced in the air by the reaction of two or more primary pollutants. Ozone Formaldehyde Photochemical smog Peroxy acetyl nitrate (PAN) Carbon Monoxide Effects on humans:- The high concentration of CO can cause death The combination of CO and hemoglobin leads to the formation of carboxylhaemoglobin (COHb) reduces the oxygen carrying capacity of blood. At concentration of 100 ppm people experience dizziness and headache. The cigarette smoke contains 400 to 450 ppm CO the percentage of COHb in blood of cigarette smokers increases with increase in smoking. At concentration of 750 ppm of CO it will cause death. Effects on plants:- CO reduces nitrogen fixing capacity of bacteria. Which affects the plant growth. High concentration of causes leaf drops, reduces the size of leaf and ageing Oxides of Sulphur Effects on human health:- It causes irritation of eyes and respiratory tracts. Increase in SO2 concentration in the atmosphere, may lead to lung cancer SO2 may obstruct breathing SO2 leads to the formation of H2 SO4 which is 20 times more irritant than SO2 Effects on Plants:- The low concentration for long period may cause discoloration of leaves SO2 affects the growth of plants At high concentration the leaf tissues gets damaged. H2SO4 is extremely toxic to plants and soil fertility. Effects on Materials:- The Sulphuric acid will attack building materials containing carbonates. This will form CaSO4 the CaSO4 gets easily washed away leaving discolored surface Oxides of Nitrogen Effects on Human Health:- Nitric Oxide reduces the Oxygen carrying capacity of blood. Nitrogen dioxide causes irritation of lungs High level of NOx causes pneumonia, lung cancer, oxygen deficiency. NOx causes irritation of respiratory system, nervous system and digestive tracts. NOx is extremely dangerous to human health. Effects on Vegetation:- NO2 and primary pollutants can damage plant tissues High concentration of NO Causes Damage to leaves. Secondary Pollutants such as smog, O3 may damage the vegetation Effects on Materials:- Nitric acid causes corrosion to metal surface NO2 fades the color of clothes NO2 causes cracking of rubber Hydrocarbon Effects on human health:- Aromatic hydrocarbon may lead to cancer Inhalation of hydrocarbon causes irritation of respiratory tract. Methane creates narcotic effects on human beings Most of the hydrocarbon are carcinogenic to lungs Effects on Vegetation:- HC affects plant growth Discoloration of leaves Effects on Materials:- It causes discoloration of materials Material becomes less elastic and more brittle.  National Ambient Air Quality Sr No Pollutant and time-weighted Industrial area Residential area Sensitive area average 1 Sulphur dioxide 80.00 60.00 15.00 Annual average 120.00 µg/m3 80.00 µg/m3 30.00 µg/m3 24 hours 2 Nitrogen oxides Annual average 80.00 60.00 15.00 24 hours 120.00 80.00 30.00 3 RSPM (less than 10 µgm) Annual average 20.00 60.00 50.00 24 hours 150.00 100.00 75.00 4 SPM 360.00 140.00 70.00 Annual average 500.00 200.00 100.00 24 hours 5 LEAD 1.00 0.75 0.500 Annual average 1.50 1.00 0.750 24 hours 6 CO 5.00 2.00 1.00 Annual average 10.00 4.00 2.00 24 hours  Control of Air Pollution Proper air pollution control devices in industries Using low sulphur coal Regular engine tune up, replacement of old more polluting vehicles Using mass transport system, bicycles etc Shifting to less polluting fuels Planting more trees No to FIRE CRACKERS in Diwali and other occasions  Pollution Control Devices Cyclone Separator Bag House Filter THANK YOU