Man's quest for progress is eternal. In his zeal to achieve scientific and technological advancement, which he hopes would make his life happier, man is unwittingly endangering the surroundings and tilting the ecological balance. Some of these are a result of unimaginative planning and reckless execution. The wanton destruction of vegetation with gay abandon and the prolific construction of concrete jungles in its place, coupled with the unconscionable disposal of even toxic industrial wastes into the air threaten the very survival of the humankind. ‘Man will thus kill himself if he thoughtlessly and violently upsets the delicate web of environment of which he is a part’. Everyone is crying hoarse from house tops about the need to protect environment But it is only a few like Sundarlal Bahuguna and Medha Patkar that have been making a valiant effort, even risking their lives, to bring awareness among the public in this regard. Even scientists and engineers confine their protests merely to paying lip sympathy. This is due to a total lack of understanding of the deleterious effects of environmental pollution. It is with a view to educating these elite sections of the society that a humble attempt is made by this author in highlighting the probable causes of air pollution suggesting remedial measures for minimising iL Every effort has been made to make the subject matter easily understandable even by a layman, in the fond hope that everyone would make his contribution towards providing a safer and cleaner environment. The reproduction of some of the material from the publications of the Bureau of Indian Standards is acknowledged. Extensive reference has been made to contributions by various authors, which is also gratefully acknowledged. The help rendered directly or indirectly, by several friends and well-wishers, in bringing out this book in its present form is also placed on record with appreciation and a sense of gratitude. As mentioned earlier, this is a humble attempt and the first by the author. Any suggestion for the improvement of this book to make it a more effective and useful tool in disseminating the knowledge on this most important subject of air pollution is wholeheartedly welcome
Additional Info
  • Publisher: Laxmi Publications
  • Language: English
  • ISBN : 978-93-83828-59-3
  • Chapter 1

    Introduction Price 2.99  |  2.99 Rewards Points

    Man is the most beautiful of all God’s creation. Shakespeare, the Bard of Avon, grew eloquent in singing about the beauty of man. “What a piece of work is man, How noble in reason How infinite in faculties In form and moving, how express In action how like an angel In apprehension how like a god The beauty of the world The paragon of animals” Man is created to enjoy the bountiful nature bestowed on him by God. Environment means the surroundings in which we live. It is a life-sustaining system in which various living beings like animals, including man, birds, insects, microorganisms like algae, fungi, protozoa, amoeba and non-living beings like air, water and soil are interrelated. Like man, his environment too is beautiful. The earth is a wonderful planet that has perennial sources of water to quench his thirst with their sweet water. Its atmosphere supplies pure air for him to breathe and has a natural ozone umbrella that protects him from sun’s dangerous ultraviolet rays. It has a green carpet to utilize the carbon dioxide that we exhale to recycle it into oxygen essential to sustain life on this planet. It has number of attractions like the rainbow to wonder at.
  • Chapter 2

    Sources of air pollution Price 2.99  |  2.99 Rewards Points

    One of the early steps involving air pollution problems is to locate the source from which air contaminants are being emitted. There are more than 7,50,000 man-made chemicals present in our environment and to these 1000–2000 new ones are added every year. Massive production of such chemicals directly or indirectly releases thousands of tonnes of a variety of air pollutants into the atmosphere. Some of the air pollutants emanated into the atmosphere by man are CO, CO2, SPM, SOx, odours, noise, NH3, gases and vapours, dusts of toxic metals like Lead, Arsenic, Asbestos, Nickel, Mercury, Phosphorus and their oxides, Vanadium, Zinc, various hydrocarbons, Fluorides etc. The pollution made by man is vast and the pollutants made by men are plentiful.
  • Chapter 3

    Effects of air pollutants Price 2.99  |  2.99 Rewards Points

    A normal human being breathes about 25,000 times a day at a rate of about 1–2 litres of air per breath i.e., about 25,000 to 50,000 litres/day i.e., about 30 to 60 kg of air per day. Thus the quantity of air consumed by an average man is about 25 times more by weight and 20,000 times more by volume than the quantity of water consumed. A person can survive for five weeks without food and five days without water but only five minutes without air. In addition, the air we breath interacts with the most sensitive organs of human body. Hence the air we breath must be of a very good quality. Unfortunately man is not equipped with household or portable air cleaning devices unlike water filters etc. and thus demands a clean ambient air for his health and well-being which is more than a luxury today. Air that surrounds a man has a direct impact on his health and property. The health of a man is determined by the interplay and integration of the internal environment of man himself and the external environment that surrounds him. A disease is only due to a disturbance in the delicate balance between man and his environment. Now a days it is not only stacks or chimneys alone where soot is detected as a cause of cancer but carcinogens are found else where also in the environ- ment where very potent cancer causing agents such as benzopyrene and many other polyaromatic hydrocarbons are present in significant concentrations in air. Of course, man is the primary source of air pollutants. He breathes fresh air and emits polluted air containing pathogens and other aeroallergens, CO, CO2 and odours. A study by the World Health Organisation shows that 75–90% of all cancers are caused due to environmental factors and are related to agents present in air, water, work environment and personal choice of lifestyle including tobacco smoking and chewing, alcohol consumption and sexual promiscuity. The effects of air pollutants on atmosphere, animals including man, materials and vegetation are thoroughly discussed in this chapter.
  • Chapter 4

    Global effects of air pollution Price 2.99  |  2.99 Rewards Points

    Tropospheric and stratospheric ozone depletion, aerosol scattering and absorption of solar and terrestrial radiation, greenhouse gas warming, rain and precipitation quality, long-range trans- port of air pollutants, heat-islands and urban air quality are known to be the main global air pollution problems. Man at the end of the 20th century has at last realized that the complexities of pollutant interaction with the atmosphere are not confined to a local scale. In the name of ‘Pollution Control by Dilution’ millions of tonnes of a variety of toxic air pollutants are released into the atmosphere by man which are transported to places several thousands of kilometers away from the source through atmospheric circulation systems causing irreparable damage to the quality of air on continental and global scales. The impacts of air pollution on biosphere and the quality of life have drawn considerable public attention, and air pollution problems are being considered and tackled on a global scale. The word ‘global’ need not necessarily mean that the pollutant under consideration encompasses the entire globe and are not unique to individual locations. The envi- ronment in which we live is unfortunately the host medium for air pollutants also. Man is the sole culprit in polluting the air and he alone should take the responsibility to clean the atmosphere and protect the environment. The various global effects of air pollution are discussed in this chapter.
  • Chapter 5

    Meteorology and plume dispersion Price 2.99  |  2.99 Rewards Points

    Meteorology means the study of earth’s atmosphere. A close relationship exists between air pollution and certain atmospheric conditions like heat, temperature, wind speed and its direction, humidity and precipitation, and it is essential for an environmental engineer to have a thorough understanding of meteorology. Pollutants emanated by various sources into the atmosphere are transported and dispersed by meteorological and topographical conditions. The air borne cycle is initiated with emission of pollutants followed by their transport, diffusion or concentration in the atmosphere and completed by deposition on soil, vegetation, live stock, water surfaces and other objects and these pollutants are finally washed out of the atmosphere by rain or precipitation. In some cases the pollutants may be reinserted into the atmosphere by wind. Many air pollution episodes involved topographical and meteorological conditions that restricted dispersion of air pollutants, causing them to accumulate at harmful levels. In highly urbanised and industrialized areas the pollutants may hasten the deterioration of the buildings and adversely affect men, material and vegetation. Majority of secondary air pollutants like smog are formed due to the interaction of the primary pollutants with the atmospheric constituents. The results of such transformations may not always be harmful as in the case of the formation of some mineral salts that are necessary for plant life. However, in large urban areas, pollutants emitted from numerous concentrated sources as well as distributed sources are dispersed over the entire geographical area. Any given location within the urban area receives pollutants from different sources in varying amounts depending upon prevailing winds, presence of tall buildings etc. If the allowable concentration of a selected pollutant at a given location is not to be exceeded, the contributions made by different individual sources must be clearly established.
  • Chapter 6

    Thermodynamics and air pollution Price 2.99  |  2.99 Rewards Points

    Thermodynamics is the science of energy transfer and its effect on the physical properties of substances. The applications of the laws of thermodynamics are found in almost all fields of air pollution, from formation to control. The principles of thermodynamics, as such, are the basics in the fields of energy technologies notably in steam and nuclear power plants, internal combustion engines, gas turbines, air-conditioning, refrigeration, gas dynamics, jet propulsion, compressors, chemical process plants and direct energy conversion devices. Today energy conservation is the main consideration in an effective project management. Sun is the basic source of energy (sufficient for 10 billion years) and any reduction in the amounts of incoming solar energy would be detrimental to life on earth. Air pollution control devices could result in an overall gain of energy and in the short-term evaluation, the control mechanism that provides the most effective emission reduction at a minimum expenditure of energy is usually used. A thorough study of the role of thermodynamics reveals that the techniques to improve energy conservation can also be the techniques to control air pollution. The study of thermodynamics is useful not only in controlling the emissions of pollutants in the plant but also in reducing the concentrations of pollutants after their discharge into the atmosphere from chimneys. The thermodynamics of formation of CO, SOx and NOx and combustion are described in detail in this chapter.
  • Chapter 7

    Particulate control technology Price 2.99  |  2.99 Rewards Points

    Everyday about half-a-million tonne of particulates (of sizes ranging from 100 to 0.1 microns and even less) are released into the atmosphere by anthropogenic sources. Particulates on a micro-scale cause severe effects on man, material and vegetation and on a macro-scale affect the earth-atmosphere heat balance by disturbing the evaporation-condensation cycle. Many cities all over the world are experiencing undesirable concentrations of particulates in the atmosphere. Particulates present in air in the form of aerosols, dusts, mist, smoke, smog, smaze or cloud, pose a potential pollution hazard and the already worsened situation demands an immediate relief by means of a proper particulate control technology. As particulates are more clearly seen, their removal from flue gases has assumed greater significance in the recent past. There are three broad approaches to the control of particulates—dilution in the atmosphere, control at source and control by using pollution control equipments.
  • Chapter 8

    Control of gaseous pollutants Price 2.99  |  2.99 Rewards Points

    This chapter deals with the removal of gaseous pollutants from the carrier gas which is usually air. The principal gases of concern in air pollution control are the sulfur oxides (SOx), nitrogen oxides (NOx), carbon oxides (CO, CO2), organic and inorganic acidic gases and hydrocarbons (EC). For the control of above mentioned gases, the mechanisms are chemical engineering unit operations which include adsorption, absorption, condensation and combustion. In addition to these unit opera- tions, a general concept such as mass transfer is used in the unit operations. Gaseous pollutant streams are like chemical process streams. The major exception is that the gaseous pollutant concentrations are usually lower than the chemical process stream concentrations. These lower concentrations make it possible to consider gaseous pollutants as ideal gases. Also, the carrier gas (air), may be treated as an ideal gas in the operating range for most of the air pollution control equipments. Gaseous pollutants can be controlled by a wide variety of devices and choosing the most cost- effective, most efficient units requires careful attention to the particular case for which the control devices are intended.
  • Chapter 9

    Sox control technology Price 2.99  |  2.99 Rewards Points

    SOx includes six different gaseous compounds of sulphur namely, sulphur monoxide, SO; sulphur dioxide, SO2; sulphur trioxide, SO3; sulphur tetroxide SO4; sulphur sesquioxide, S2O3 and sulphur heptoxide, S2O7 out of which SO2 and SO3 are the most significant in air pollution. SO2 is a colour- less nonflammable and non explosive gas with a suffocating odour. It has an odour threshold of 0.5 ppm and taste threshold of 0.3 ppm. It is highly soluble in water at about 113 grams per litre at 20°C. It has a molecular weight of 64.06 and is about twice as heavy as air. It has a residence time of 2–4 days during which it can be transported to as far as 1000km. It is relatively stable in the atmosphere. It reacts photochemically to form SO3, H2SO4 or salts of sulfuric acid. It reacts with water vapour in air to form a weak acid, the sulphurous acid. SO2 + H2O H2SO3 (Sulfurous acid)  SO3 + H2O H2SO4 (Sulfuric acid)  SO2 may be considered as the most significant air pollutant due to its ability to interfere with man and nature on both micro and macro scales. About 70% of acid rains are due to SOx emissions and SOx is the main culprit in affecting human health, destroying vegetation and damaging mate- rials and art-treasures. SOx control technology has assumed a great significance in the recent past as a means of preserving and protecting the environment. Everyday about one million tonne of SO2 is released into the atmosphere from anthropogenic sources. It is primarily generated from the combustion of all fossil fuels-coal, petroleum and natural gas in industries and thermal power plants and small domestic units. Due to high population escalation these domestic units compete with any big industry as they can never have a pollution control system and many times may even exceed the levels of the former. Many cities all over the world are experiencing undesirable concentrations of SOx (Ref. Table given below) and the situation demands immediate measures to mitigate SOx emissions by proper control technology. Mean annual concentrations of sulphur dioxide between 1976 and 1980 for cities in the GEMS network are presented below. The USEPA standard is included for comparision.
  • Chapter 10

    No x control technology Price 2.99  |  2.99 Rewards Points

    NOx is one of the four major air pollutants and is the element primarily responsible for the formation of photochemical smog. About 30% of acid rains also are due to NOx. There are two sources of nitrogen which contribute to the formation of nitrogen oxides during combustion—one is the atmospheric nitrogen and the other is the nitrogen present in the fuel itself. Nitrogen without me presence of any known catalyst, combines with oxygen during combustion to form oxides of nitrogen. The various reasons for the increase of oxides of nitrogen in the ambient atmosphere may be the increased emissions of NOx from industries and automobiles and various other sources. Well over 90% of all the man-made nitrogen oxides that enter our atmosphere are produced by the combustion of various fuels. The real danger posed by NOx at the concentrations found in metropolitan areas lies in its role in photochemical reactions leading to smog formation. These atmospheric reactions lead to the for- mation of chemical compounds that do have a direct adverse effect on human beings and plants. In some situations, NOx may be present in a high enough concentration, yet not react to form smog because other necessary conditions for the reaction are absent. However, nearly every major city in India at times experiences the effects induced by the presence of NOx. The actual quantities of NOx produced by any given industry can be quite large. For example, a 750-MW gas or coal fired power plant produces around 75 to 100 tonnes of NOx per day. The type of fuel used can change the amount of NOx released significantly. About 60% of NOx is contributed by fuel combustion in the stationary sources and about 40% by transportation. The stable gaseous oxides of nitrogen include N2O (nitrous oxide), NO (nitric oxide), N2O3 (nitrogen trioxide), NO2 (nitrogen dioxide) and N2O5 (nitrogen pentoxide). An unstable form, NO3 also exists. Of all these oxides of nitrogen the only ones present in the atmosphere in any significant amount are N2O, NO and NO2. These three are the potential contributors to air pollution. The main chemical reactions in the formation of nitrogen oxides
  • Chapter 11

    Noise pollution Price 2.99  |  2.99 Rewards Points

    Unwanted sound is called noise. The noises of modern society are profoundly annoying to the individual human being. One noisy motorcyclist or scooterist crossing a city can disturb the sleep of many people. The most important change which is evident in most places in this century, is the explosion of human population. This has exerted pressure on all available resources. One of them is significant rise of noise level. Not only raised human voices but also sound from various sources like construction sites, loudspeakers, radio, microphone, automobiles, aeroplanes, railway engines, irrigation pumps etc., break the silence of the environment. Noise has gained such an intensity that it grates on everyone’s nerves. Surveys of complaints and physical measurements, all show noise pollution to be one of the major hazards of modem life, especially in urban areas— areas which are the most industrialized, urbanized and motorized. Surveys show that noise is now perceived in many countries to be the major negative factor affecting the quality of life. In the United States, for example, noise is ranked second only to crime. In West Germany, a 1979 poll indicated that 45 per cent of the population believed that the protection against noise is more important than building new roads. In Japan, there are currently more complaints about noise than about any other form of pollution. It is high time to realise the importance of protection against noise pollution on global basis. It will not be untrue to admit that Indians are noisy people. In India, every occasion or sentiment is manifested in a noisy manner-be it a religious occasion, an election or a family celebration.
  • Chapter 12

    Indoor air pollution Price 2.99  |  2.99 Rewards Points

    In order to stay alive, a person has to inhale about 25,000 breaths of air each day i.e., about 25 m3 of air per day. The air should be fresh and clean. As civilisation improved man has constrained his life to indoors and started living more and more indoors within the structures built by him. This led to the severe problem of “Indoor Pollution”. Man and several thousands of household products made by him pose a serious threat to indoor air quality. These products include cleaners, detergents, paints, air fresheners, disinfectants, insecticides etc. Indoor air pollution often leads to severe health hazards like irritation to the eyes, nose, throat, headache and most importantly the respiratory problems. The indoor pollution also leads to buildup of mental tensions leading to severe decrease in productivity among factory workers. Workers in polluted atmosphere are supposed to be subjected to severe fatigue than the workers in normal environment. Indoor environments often have higher levels of air pollutants than their surroundings in rural as well as urban areas.
  • Chapter 13

    Odour pollution Price 2.99  |  2.99 Rewards Points

    ‘Odour’ is undoubtedly the most complex problem of air pollution. Unfortunately, the only good measuring device for odour pollution is the human nose, which is notoriously undependable. Some individuals cannot detect odours easily whereas some have the ability to detect very minute quantities of substances in the range of 1 ppb also. Moreover, people have a mixed reaction to a given odour. Perfumes, very much liked by some people, may be very much disliked by others. There is a marked disagreement with reference to the offensiveness of selected odours. In addition, there are two other problems which interfere with the detection and measurement of odour. They are (i) unfamiliar odour is more easily detected and is more likely to cause complaints than a familiar one and (ii) because of odour fatigue, given sufficient time, a person may become accustomed to almost any odour and be conscious of it only when a significant change in intensity occurs. Food processing, oil refining, paper and rubber industries, tanneries, sugar mills, distilleries etc., are the major odour emitting industries. Odours may not cause direct damage but are as much a nuisance as noise, dust or corrosion. Until now, very little attention was given to the control of odorous air contaminants, consequently, Osmics, the science of smell, has remained unexplored to a great extent.
  • Chapter 14

    Automobile pollution Price 2.99  |  2.99 Rewards Points

    Transportation is the main reason for air pollution especially in urban areas, where 60% of the air pollution is caused by automobiles only. The problem is of much concern in our country as the vehicular population is increasing at an alarming rate every year. The number of four wheelers are going up by 10 per cent every year while two and three wheelers by about 20 per cent. For example, in India, the number of two wheelers in 1970 and 1988 are 50 and 82 lakhs respectively and the number of passenger cars in 1970 and 1988 are 6.5 and 16 lakhs respectively. United States, with more than one vehicle for every one person in the country, alone burns more than 200 billion gallons of gasoline per year. The problem of automobile pollution is far more serious than one can imagine and therefore, the assessment of the impact of vehicular pollution on urban environment is essential. Vehicles travelling in major metropolitan areas are estimated to account for 80% of all carbon monoxide, 50% of hydrocarbons, 30–40% of oxides of nitrogen and almost 100% of the lead present as air pollutant Mobile combustion sources include automobiles, trucks, buses, rail-road locomotives, aircraft and marine vessels. Pollutants from these sources contain both toxic compounds and organic materials that are not in themselves objectionable but which react in the atmosphere to form smog which is highly objectionable
  • Chapter 15

    Air pollution monitoring and management Price 2.99  |  2.99 Rewards Points

    The objective of monitoring and management of air pollution is to protect man and his property. Continuous monitoring of ambient air quality and stack-gas emissions is necessary to develop background concentrations of different pollutants in an area, to evaluate the performance of the air pollution control measures adopted and finally to check whether the concentrations of pollutants are within the prescribed limits or not. Monitoring meteorological parameters such as wind speed and wind direction, temperature and environmental lapse rate, humidity and precipitation, alongwith the concentrations of pollutants both in stack and in ambient air would help in the successful management of air pollution control problems and in arriving at new air pollution standards. Air pollution can be reduced by a great extent even before setting up an industry by locating it at a suitable site and by conducting a thorough Environmental Impact Assessment. After commission- ing the industry, the pollutants can be minimised by following a good environmental management plan. As air pollution control is often a costly affair with no direct beneficial returns, many indus- tries show little interest in air pollution control management. A thorough monitoring of the air pollutants and a strict implementation of the legislations only can control air pollution and bring air quality to the required standards.

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