Effects and Prevention of air pollution

 

Effects and Prevention of air pollution :

Introduction

Effects and Prevention of 

air pollution : It is all about air pollution's effects. How the polluted air is affecting human and animals. And i explained how to prevent the air pollution.  

                              Details

(A) INDUSTRIAL AIR POLLUTION

      Air is mostly polluted due to industrial releases. Effects and Prevention of air pollution. The fossil fuels used for co-

mbustion purposes destroy the quality of atmosphere air due to their contamination. Different organic and inorganic materials used as the raw materials for industrial purposes equally share their role in polluting the surrounding industrial air due to residues they release during man-ufacture. Byproducts and waste subs-tances during industrial manufacturing process are further destroying the quality of air. Role of industries in polluting the air may be discussed as below:↓↓↓↓

     1. Chimney Wastes : The wastes released out in form of gases and dusts through the chimnies are the major sources of air pollution. Effects and Prevention of air pollution. The petroleum refinery units emit the poisonous gases with major components of oxides of sulphur and oxides of nitrogen. Theseg ases destroy the biosphere and also valuable properties related to arts and sculptures. The Mathura petroleum refinery plant threatens the beauty of Taj Mahal and other monuments of Fathehpur Sikri. Food processing industries, textile and paper industries, cement industries are some of the high ranking air polluting industries.

     2. Carbon Compounds : Carbon co-mpounds consisting of carbon dioxide and carbon monoxide are released by c-ombustion of fossil fuels in industries. Of course carbon monoxide releases in less proportion during the utilization of fossil fuels. Increasing in concentrationo f carbon contents in the atmosphere deteriorates the air quality for respiration purposes. Carbon monoxide is very dangerous. Even though major amount of carbon monoxide is emitted form automobiles, yet a considerable proportion is also shared by industrial releases. At concentration level of 100ppm in the atmosphere the CO becomes fatal to human and other animal lives. This concentration of carbon monoxide can cause uncor.sciousness in an hour and death may be caused in about 4 hours. A concentration of about 175 ppm inhaled for a few minutes may cause serious poisonous effect on man.  Effects and Prevention of air pollution

     3. Sulphur Compounds : These are released from the refinery industries and the industries related with fossil fuel power generating systems. The sulphur containing compounds thus causing air pollution are consisted of carbonyl sulphide (COS), carbon disulphide (CS) dimethyl sulphide [(CH2),S], hydrogen sulphide (HS), sulphur dioxide (SO2) and sulphate (SO.). Oxides of sulphur coming in contact with atmospheric humidityf orm sulphurous acid which subsequently forms sulphuric acid. Flora and fauna are greatly damaged by these sulphur compounds.

     4. Nitrogen Oxides : Besides aut-

omobiles, power generating units variable

industries are contributing the addition of nitrous oxide, nitric oxide and nitrogen dioxide etc. to the atmosphere resulting air polluting. Nitric oxide (NO) causes different atmosphere photochemical problems and result several secondary pollutants like carbonyl compounds,peroxyacetyl nitrate (PAN) etc. These cause hazardous effects on biosphere.

     5. Chloroflurocarbons:

     Chlorofluorocarbon are used in refrigerator, coolants, solvents in aerosol sprays, in manufacture of foam and plastics, in paints and varnish industries are considered now a days as one of "High degree pollutants". These chlrofluoro carbons (CFCs) are the main sources depleting the ozone layer. Due to the photo dissociation of CFCs free chlorine is released which subsequently effects the ozone layer.

     6. Thermal Power Plants : Coal is being used in large scales in thermal powerplants. The National Thermal Power Corporation (NTPC) is running four coal based power plants for energy generation. Flyash, sulphur dioxide and different hydrocarbons are released out during coal utilization causing air pollution.

     7. Metal Pollutants : Industries are also responsible adding different metals (intraces) in the atmosphere causing the air pollution. Mostly these metals are contaminated in the air from metallurgical processes. Steel plants, zinc plants, aluminium, arsenir plants etc. are mainly contributing such pollutants. Nickel, arsenic, tin, lead, vanadium, titanium

etc. are commonly found in air polluting the atmosphere.

     8. Particulate Matters : Paper industries, textile mills, cement industries etc. release huge quantity of wastes in particles contaminating the atmosphere. These pollutants cause different gastro-respiratory problems in animals including man.

     9. Photochemical products : Dye industries, soap and detergent manufacturing units, paint and varnish industries release the photochemical smog, peroxy acetyl nitrate (PAN) etc. causing air pollution.

(B) Sources and Fate of Air Pollutants

     The chief sources of atmospheric pollutants and their fate in the envir-

onment are as follows:

     1. Carbon compounds : Carbon dioxide is released during combustion of fossil fuels, organic substances and respiration of organisms. Carbon monoxide enters into air by automobile exhaust mainly. Air is polluted by these carbon compounds.

     2. Nitrogen Compounds : Nitrogen oxide, nitric oxide, nitrogen dioxide are released from industries, power generating plant, automobiles etc. Nitrogen dioxide reacting with atmospheric humidity may from nitric acid. These pollutant cause serious atmospheric problems on the biosphere.

     3. Sulphur Compounds : The sulphur compound include sulphur dioxide, hydrogen sulphide and sulphuric acid which are air pollutants easily con-taminate with the atmosphere. These are released from industries, vehicles etc.

     4. Hydrocarbons : Industries are mainly concerned for the discharge of hyd-rocarbons to the atmosphere causing air pollution. Benzene, Benzopyrine etc. are some of the hydrocarbons. 

     5. Metals : Volcanic erruption, industrial discharges, power plants etc. are thes sources of metal pollutants. The metals in this group include arsenic, tin, nickel, cadmium etc.

     6. Particles : Industrial refuses, dusts, carbon particles, organic substances are the sources of particles which cause the atmospheric pollution.

     7. Photochemicals : The sources of these pollutants are different industries, power generating units, refineries and to some extent automobiles. These pollutants include peroxyacyl nitrate, hydrogen peroxide, organic peroxides, ozone etc. These cause serious health hazards on animals and destroy the vegetation.

     8. Fluoride Compounds : These are also industrially released air pollutants de-

stroying the ozone layer.

(C) Effects of Air Pollution

     Air pollution imbalances the enviro-nmental strategy. The pollutants entern into the body system of plants and animals through bio-geo chemical cycles. A part of the air pollutants may reach the land as dry fallouts. These can enter into the food chains through water . Effects and Prevention of air pollution.The productivity of crops can be declined due to air pollutants.lAnimals including human beings are affected considerably by air pollution. Black lung diseases, emphysema, bronchitis, skin allergies, lung cancers are some of the human diseases caused by these pollutants. Climatic disorders like increasing of temperature, rapid run-off of water, lowering of wind velocity, increased cloudiness, variation in solar radiation etc. caused by air pollutants directly or indirectly affect the biosphere. The state of air pollution in modern cities is beyond ones imagination. In Mexico city one takes equivalent of smoking two packs of cigarettes per day in the breathing air. More than 30,000 factories and three million cars of Maxico City are polluting its atmosphere. In the count of suspended particulate matter (SPM) in the air, Calcutta is ranking the top position in the world. Due to the entry of huge numbers of two-wheelers in Indian roads every year air of the urban areas is greatly threatened. In the metropolitan cities of India it has been estimated that vehicular exhaust accounts for about 72% of carbon monoxide, 50% of hydro carbons and more than 30% of particulate matter polluting the air. Smog is very often observed in metropolitan areas. It reduces the visibility so badly forces the temporary closure of air ports and almost stops the vehicular traffic moves for a considerable time Air pollution causes serious health hazards besides destroying valuable properties including arts and sculptures.

Prevention and Control of Air Pollution

     Almost all advanced and developing countries including India are now aware

to the problem of atmospheric pollution. Effects and Prevention of air pollution. After the Bhopal gas tragedy 1984 and the

published report of Centre for Science and Environment 1984-85, in which the Centre

has warned 31 thermal stations out of 48 units supervised by it. The environment

protection act was passed by the Govt. of India in 1986. Vehicular pollution is the

major concern in India causing air pollution. utomobile emissions are related to the

(1) exhaust system,

(2) crankers and 

(3) fuel tank with the carburettor of the vehicle.

    Various control measures are adopted to check exhaust emission of pollutants are:

(1) gasoline and air proportion 

(2) injection for conversion of exhausts to less toxic substances 

(3) timing of fuel feeding

 (4) gas additives for improving combustion of fuel etc. 

    Carbon monoxide is formed from the low air content of the fuel mixture. High combustion temperature results the formation of oxides of nitrogen. Thus preventive steps should be taken to minimise such pollutants to be released from motor vehicles. Due to volatile property of the petroleum fuels, evaporation from vehicle tanks cause emission of hydrocarbons to the air. Intermittent stop of the engine increases the rate of evaporation through carburettor. Suggestions may be made to control the evaporation from fuel tank as :

(i) to lower the pressure in the tank 

(ii) introduction of low-volatile gasoline

(iii) collection of gasoline vapours with active charcoal etc.

     Oxides of sulphur, carbon disulphide, hydrogen sulphide, oxides of nitrogen,

oxides of carbon, chlorinated compounds etc. are generally released out as industrial by products to the atmosphere causing air pollution. Thermal plants are responsible for bleaching and acid rain. Textile, paper and cement industries which emit plenty of dust cause great hazards in plants and animals. Removal of particulate and gaseous pollutants from chimney waste may check industrial air pollution to a considerable extent. The methods in applying the equipments for the said purpose are as :

(i) Cyclone collectors : About 70% of the particles can be removed by these

equipments. Due to centrifugal force particles, dust particles can be separated

and discharged by this method at the bottom part of cyclone collectors.

(ii) Electro static precipitators (EPs): This is the process of removing particles

from the gas stream by applying electrical forces. About 99% of the particulate

pollutants from chimney exhaust can be removed by such equipments. Textiles

industries, paper mills, cement factories, carbon block plants etc. work very

effectively in this method. At times filters are employed particularly in industries

releasing high resistive dusts.

Gaseous pollutants can be removed as:

(i) Wet Systems: It is the technique of having washing towers with circulating

alkali liquid reacting with SO, to produce precipitate.

(ii) Dry Systems : In this process the gas pollutants are subjected to react with an absorbent under a dry condition. Lime and dolomite are kept to react with sulphur dioxide. Water is subsequently sprayed thus producing sulphuric acid.

(iii) Wet-dry Systems : In this process water in the absorbent reacts with the acid components. It is an alternative to wet process for desulphurisation of fuel gases from coal fired boilers. The absorbent calcium hydroxide slurry is spread into the hot gas stream in small droplets. Calcium reacts with sulphur dioxide and the hot gases evaporate the water, thus making the end products mostly fly ash and salts. Charcoal can also be used as an absorbent. Other absorber can be used to pick up alcohols and benzenes. This method is effective in paint factories, printing press, pharmacetutical industries, petroleum industries etc.

Feature :

The main feature is if we did this or prevent this the air will be pure there will no harmful gases or chemicals. And there will not be lung cancer, etc. Deseasses to the people or animals also. 

Control Through Laws

     Acts and laws are to be enforced for industries to minimise the release of by-products to the atmosphere. In India Air Pollution Control Act envisages the formation of Air Pollution Board at the Central and Provincial levels with powers to issue and revoke licenses to polluting industries and frame rules and regulations for the control of air pollution.

Conclusion

     And my opinion is we need to use this prevent technique to prevent the air. Because the polluted air is affecting us. So this is our responsibility to cure it. And thanks to visit this site. Effects and Prevention of air pollution.