The assessment of air quality and control of air pollution are difficult tasks facing an environmental manager. Both soil and water can be confined and gathered at one place while air cannot be gathered and confined in one place. Hence air quality assessment, air pollution prevention strategies and control technologies are of great importance in air quality management
SO2 emissions can be reduced by using fuels with the lowest possible S content: considerable advances have been made in the removal of S from fuels (including pulverized coal) before combustion. Consequently, the balance between the higher costs of such fuels and those associated with the installation of additional pollution controls is now becoming important.
air pollution and control technologies by anjaneyulu pdf 12
Fig. 1.14 Graphical representation of new source performance standards for SO2 emissions from coal-fired power plants(Source: J. Mol burg, 1980. A graphical representation of the NSPS for sulphur dioxide. Journal of air pollution control association. 30(1): 172.)
Cell and leaf anatomy: Since the leaf is the primary indicator of air pollution effects on plants, the functions of the leaf are given below. Aty pical plant cell has three main components (Fig. 1.17): the cell wall, the protoplast, and the inclusions. Much like the human skin, the cell wall is thin in young plants and gradually thickens with age. Protoplast is the tenn used to describe the protoplasm of one cell. It consists primarily of water, but it also includes protein, fat, and carbohydrates. Tire nucleus is the dense bit of protoplasm that controls the operation of the cell. Tire protoplasm located outside the nucleus is called cytoplasm. Within the cytoplasm arc three types of tiny bodies or plastids: chloroplasts, leucoplasts and chromoplasts. Chloroplasts contain the chlorophyll that manufactures the plant's food through photosynthesis. Leucoplasts convert starch into starch grains. Chromoplasts are responsible for the red. yellow and orange colour of the fruit and flowers.
Dr. Anjaneyulu Yerramilli, Ph.D is presently working as visiting Professor in Chemistry/Environment at Jackson State University, Jackson, MS. During his career in India he amassed 35 years of research and teaching experience in Environmental/Energy technologies, 34 Ph.D students received Ph.D degrees under his supervision, he published more than 100 research papers in peer reviewed journals and presented at various international conferences. He has authored a number of books on Environmental Impact Assessment Methodologies (2011, BS Publications / CRC Press / Balkema), Introduction to Environmental Science (2005, BS Publications), and Hazardous Waste Management, Air Pollution and Control Technologies (2002, Allied Publishers). He has expertise in EIA, Energy Technologies, Risk Assessment and Air Pollution modeling. He is presently working as PI for two programs: i) a Department of Defense-sponsored program on High Performance Computation for Development of Novel Materials and ii) Atmospheric Dispersion Modeling of Gulf Coast, sponsored by NOAA, and as co-PI for a NSF-sponsored program on Collaborative Research CI-TEAM Demonstration Project entitled Water HUB for Cyber Enabled Training, Education, and Research in Water Resources. He has also published a number of papers on simulation of mesoscale coastal circulation of Gulf Coast for air pollution dispersion by integrating WRF, HYSPLIT, SMOKE and CMAQ models ( ).
Air pollution became a widespread problem in the United States (US) and, according to the Environmental Protection Agency (EPA), it is estimated that over 100 million individuals are routinely exposed to levels of air pollution that exceed one or more of their health-based standards [1]. The major air pollutants include oxides of sulfur and nitrogen, suspended particulate matter, oxides of carbon, hydrocarbons, lead. These gases are released into the atmosphere from either stationary sources such as industrial point sources or mobile sources like vehicular pollution. These pollutant gases will also produce secondary pollutant like surface Ozone, which has great oxidative capacity and is the primary component of urban smog. Criteria Pollutants Ozone and particulate matter (PM10 and PM2.5) are main focus now as they manly drive the AQI (which is based on five criteria pollutants CO, NO2, SO2, O3, PM). These pollutants can affect our health in many ways, with irritation to the eyes, nose and throat and more serious problems such as chronic respiratory disease and cardiovascular diseases. Understanding the long-term (yearly, decadal) trends of these criteria air pollutants is important for assessing chronic exposure to population and the efficacy of control strategies, emissions changes, and the year to- year influence of meteorology.
Pollutants in the atmosphere undergo transportation and dispersion, whose characteristics are dependent on the prevailing atmospheric conditions. Pollutants can be transported across the continents due to globally circulating winds on time scale of months to years, e.g. intercontinental transport of dust from Sahara desert in Northwest Africa and the Gobi desert in East Asia and dispersed over a few hundreds of miles in a few days under the influence of local scale wind circulations. While wind is primarily responsible for transportation and dispersion, topography and atmospheric stability also play an important role. Horizontal and vertical motions arise due to atmospheric pressure gradients and stability conditions. Atmospheric pressure, defined as the weight of the air column above a point, varies due to differential surface heating. Heating and cooling of the earth surface is dependent on the type of surface, for e.g. water bodies have larger specific heat capacity and so takes longer time to get heated or cooled as compared to land surface. Different surfaces have different heating/cooling rates, e.g. asphalt surface gets heated/ cooled faster than vegetation surface; heating/ cooling at the surface causes lower/ higher density vertical columns leading to lower/ higher pressures. As air tends to move from denser to lighter regions, atmospheric wind gets established as movement from high pressure regions to low pressure regions. Similarly vertical motions are dependent on atmospheric stability. Heating at surface causes air to rise mixing with cooler and denser air at higher levels leading to instability and most of the mixing takes place in the lowest part of the atmosphere referred to as atmospheric boundary layer. This is characterized by turbulent fluctuations of wind velocity, temperature and moisture due to energy exchange with earth surface capped by an infinitesimal transition layer below the free atmosphere with lower/ higher stability conditions associated with stronger/ weaker vertical mixing. Since the pollutants originate near the earth surface, characteristics of the atmospheric boundary layer play an important role in the dispersion of pollutants. This is the reason why winter nights which are cooler with higher stability have stagnation of pollutants causing health hazards. Atmospheric dispersion on the scale of a few days (synoptic time scale) is influenced by the transient surface low and high pressure systems. Moderate to intense low pressure systems characterized by winds > 5m/s, mass convergence, higher instability and upward motions contribute to dispersion over wider horizontal extent ranging up to few thousand kilometers thus reducing the pollution effect through mixing with larger environment volume. Conversely, high pressure systems with calm winds, subsiding downward motion and higher atmospheric stability contain dispersion to smaller volume enhancing the pollution effects. These emphasize the role of atmospheric stability criteria and prevailing atmospheric circulation on the atmospheric dispersion of pollutants. In the absence of synoptic forcing, mesoscale and local circulations developed due to topography and land use variations and with synoptic forcing admixture of synoptic scale and mesoscale circulations control the pollutant dispersion. 2ff7e9595c
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