Major Effects Of Air Pollution

INTRODUCTION
Worldwide, air pollution is a growing threat to human health and the natural environment. One of the major effects of air pollution is acid rain and it is caused by sulfur dioxide (SO2) and nitrogen oxides (NOx) gases. The combustion of high sulphur content fossil fuels can release harmful toxic gases into the air and therefore pose serious environmental problems. Coal, oil and natural gas are major energy resources available in environment where as fuel combustion processes and power plants are the largest contributor of these gases in the form of flue gas. Since coal and petroleum often contain sulphur compounds, their combustion generates SO2 unless the sulphur compounds are removed before burning the fuel. The gas exiting to
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Damage to air pollution control equipment, ductwork, and fans can occur if the gas temperature is below the sulphuric acid dew point in localized areas. More than 18 million metric tons of SOx are emitted into the atmosphere each year from man-made sources. Approximately 98 to 99% of the SOx emissions are in the form of SO2. These emissions can cause health problems and contribute to acid rain. Over two-thirds of all anthropogenic SOx emissions result from fossil fuel combustion in utility and industrial boilers. Coal and fuel-oil boilers are responsible for most of the utility and industrial boiler SOx emissions because these fuels have moderate-to-high fuel sulphur levels. The largest non-combustion sources are copper smelters, followed by petroleum refining operations. Other small SOx sources include residential, commercial, and institutional heating furnaces and mobile …show more content…
This term does not include nitrous oxide (N2O), which is emitted in very small quantities from some types of stationary sources. They can also be released from nitric acid plants and other types of industrial processes involving the generation and/or use of nitric acid. There are two primary reaction processes responsible for emissions of these compounds from combustion sources: (1) high temperature thermal oxidation and (2) oxidation of fuel nitrogen compounds. The high temperature oxidation reactions involve the conversion of atmospheric nitrogen (N2) to NO and NO2 in portions of the burner flame having temperatures exceeding 1400°C and high localized oxygen concentrations. The conversion of fuel nitrogen simply involves the oxidation of a portion of the nitrogen compounds often present in fossil fuels. NO is an odorless gas that is insoluble in water. NO2 is moderately soluble in aqueous liquids and has a distinct reddish-brown color. This compound contributes to the brown haze that is often associated with photochemical smog conditions in urban areas. At low temperatures such as those often present in ambient air, NO2 can form a dimmer compound (N2O4). These two gases have a significant role in formation of photo chemical smog and acid rain. NOx reacts with ammonia,

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