Ground Level Concentrations Of Sulfur Dioxide Research Articles

Analysis of the emission of SO2, NOx, and suspended particles from the thermal power plants Kostolac (Serbia)

ABSTRACTThe environmental situation related to the thermal power basin of Kostolac for the most part represents the result of the influence of the thermal power plants (TPPs) of Kostolac A, Kostolac B, and the open-pit lignite mine. The quality of air is monitored by continuously measuring concentrations of the overall precipitation matters and gases such as CO2, SO2, NOx, CO, and O3. Values significantly exceeding the legal limits have been found for pollutants in the surroundings of the TPPs Kostolac A and B and in the direction of dominant winds. The paper analyzes the impact of different scenarios of emission of harmful matters from the blocks of TPPs Kostolac A and B on the quality of air in this part of Serbia. The Gaussian model has been used to evaluate dispersion of gas substances and suspended particulates as well as parameters related to the surroundings. Calculations have been made relating to ground-level concentrations of sulfur dioxide, nitrogen oxide, and suspended particles at varying distances from the emission source.

AERMOD performance evaluation for three coal-fired electrical generating units in Southwest Indiana

An evaluation of the steady-state dispersion model AERMOD was conducted to determine its accuracy at predicting hourly ground-level concentrations of sulfur dioxide (SO2) by comparing model-predicted concentrations to a full year of monitored SO2 data. The two study sites are comprised of three coal-fired electrical generating units (EGUs) located in southwest Indiana. The sites are characterized by tall, buoyant stacks, flat terrain, multiple SO2 monitors, and relatively isolated locations. AERMOD v12060 and AERMOD v12345 with BETA options were evaluated at each study site. For the six monitor–receptor pairs evaluated, AERMOD showed generally good agreement with monitor values for the hourly 99th percentile SO2 design value, with design value ratios that ranged from 0.92 to 1.99. AERMOD was within acceptable performance limits for the Robust Highest Concentration (RHC) statistic (RHC ratios ranged from 0.54 to 1.71) at all six monitors. Analysis of the top 5% of hourly concentrations at the six monitor–receptor sites, paired in time and space, indicated poor model performance in the upper concentration range. The amount of hourly model predicted data that was within a factor of 2 of observations at these higher concentrations ranged from 14 to 43% over the six sites. Analysis of subsets of data showed consistent overprediction during low wind speed and unstable meteorological conditions, and underprediction during stable, low wind conditions. Hourly paired comparisons represent a stringent measure of model performance; however, given the potential for application of hourly model predictions to the SO2 NAAQS design value, this may be appropriate. At these two sites, AERMOD v12345 BETA options do not improve model performance. Implications: A regulatory evaluation of AERMOD utilizing quantile-quantile (Q–Q) plots, the RHC statistic, and 99th percentile design value concentrations indicates that model performance is acceptable according to widely accepted regulatory performance limits. However, a scientific evaluation examining hourly paired monitor and model values at concentrations of interest indicates overprediction and underprediction bias that is outside of acceptable model performance measures. Overprediction of 1-hr SO2 concentrations by AERMOD presents major ramifications for state and local permitting authorities when establishing emission limits.

Estimation of pollution dispersion patterns of a power plant plume in complex terrain

This study aims to identify the pollutant dispersion patterns in complex terrain under various meteorological conditions. The study area is situated at Chania plain on the island of Crete, Greece, where the topography is fairly complex. Thus, the local meteorology is expected to be deeply affected by this complex morphology. The main source of air pollution in the region is a diesel power generating plant. The daily averaged ground level distributions of sulfur dioxide, emitted from the power plant, were predicted using the AERMOD modeling system. In order to assess the meteorological conditions in the wider region, a meteorological monitoring network with six stations was installed and operated for two years. A detailed spatial and temporal analysis of the meteorological parameters is performed in order to determine their ability to characterize the transport and dispersion conditions in the area of concern. The model was applied for days with well established wind flows and the case studies indicate that such a model is capable of predicting the general pattern of ground-level concentrations of sulphur dioxide in the area of the power plant.

Uncertainty and sensitive analysis of environmental model for risk assessments: An industrial case study

The objectives of this paper are the application of uncertainty and sensitivity analysis methods in atmospheric dispersion modeling to study the prediction of the dispersion of pollutants in the atmosphere. The Gaussian Plume Model is used to study the impact of meteorology on the dispersion of the emissions from an industrial source complex. The determination of ground-level concentration and maximum ground-level concentration is useful for the prediction of violations of air quality regulations. The Industrial Source Complex Short-Term (ISCST-3) air pollution model was adopted to predict the ground-level concentration of sulfur dioxide (SO2) emitted by a power plant located in an industrial region site in Spain. Quantitative uncertainty analysis has become a common component of risk assessments. Uncertainties were defined a priori for each of the following variables: wind speed, wind direction, and pollutant emission rate. In order to obtain information about the uncertainty of computer code results, a number of code runs was performed using the nonparametric tolerance limits method. The Monte Carlo method was used to propagate uncertainty across codes. The Spearman rank correlation coefficient was used as a sensitivity measure.

The level of maternal methemoglobin during pregnancy in an air-polluted environment.

The objective of this prospective study was to determine if a correlation could be established between the ground-level concentrations of sulfur dioxide and methemoglobin concentrations in pregnant women when a coal-powered thermoelectric power plant was in operation ("dirty" period) and when it was closed ("clean" period). The location of the power plant, Plomin 1, in Labin, Croatia, was taken into consideration. Blood and urine samples of each pregnant woman in the study were tested three times in the clean period (n = 138) and three times in the dirty period (n = 122), with 1 month between each test. I observed a correlation between the increase in mean values of methemoglobin and the ground-level concentration of SO(2) on corresponding dates during the dirty period (r = 0.72, p < 0.01). In the clean period, the negative mean value of methemoglobin was significant (r = -0.60, p <or=0.05), whereas in the dirty period, the positive mean value of methemoglobin was significant (r = 0.73, p 0.01). The increase of maternal methemoglobin could be a useful biomarker to determine when the health of pregnant women is threatened by toxic substances in the environment.

Application of an ISCST3 model for predicting urban air pollution in the Izmir metropolitan area

A Gaussian atmospheric dispersion model, Industrial Source Complex Short Term (ISCST3), was used to estimate ground-level concentrations of sulphur dioxide (SO2) emitted from source categories of industrial and domestic heating in the city of Izmir, Turkey. Predictions were estimated for the year 2000 across a study area of 80 km x 100 km. Statistical analyses were carried out to evaluate the model performance by comparing predicted and observed SO2 concentrations at four ambient air quality monitoring stations using two main methods root mean square error (RMSE) and an index of agreement (d). The results showed that industry was found as the most air-polluting sector and industries located at outside of the metropolitan area were found to carry important risks for urban air quality. The most polluted area was found at a distance of about 1 km from a major petroleum refinery and a large petrochemical industry.

Game theory approach for the design of an optimal air pollution control system for thermal power plants

A procedure, based on the concept of game theory, for the optimum design of an air pollution control system in thermal power plants is described. The problem is formulated as a four-criteria optimisation problem, with the cost of the electrostatic precipitator, the cost of the stack, the maximum ground-level concentration of particulate matter and the maximum ground-level concentration of sulfur dioxide as the objectives. The efficiency of the precipitator and the height of the stack are treated as the design variables. Geometric constraints in the form of lower and upper bounds on the design variables are imposed on the problem. The design problem is formulated as a four-person game, and the Nash non-cooperative solution is evaluated for irrational play to determine the starting point of the game. For the cooperative game, a supercriterion is formulated for the overall benefit of the players. The game is terminated when the optimal trade-off between the objectives is reached with the maximisation of the supercriterion. The methodology is demonstrated by solving a practical problem related to the design of an air pollution control system for a 210 MW thermal power plant.

Ground level concentration of sulfur dioxide at Kuwait's major population centers during the oil-field fires

During the Iraqi occupation, Kuwait's oil wells were ignited. The fires were damaging to the country's oil resources and air quality. The impact of the oil-field fires on the air quality was studied to determine the level of exposure to pollutants in major population centers. The period of July–September 1991 was selected for examination. A mathematical model was used to compute the ground-level concentration of pollutants generated by the 558 burning oil wells in the eight oil fields in the principal oil production area during the investigated period. The results are presented as ground-level concentration isopleths. The results of these computations are supported by significant concentrations measured and reported by the Environmental Protection Council, Kuwait. The ground-level concentrations of sulfur dioxide in the major population centers, whether measured or estimated, were less than the ambient standards of the U.S. Environmental Protection Agency's air pollution index. The dispersive characteristics were classified according to wind conditions. The results of this assessment provide historical data on Kuwait's oil fires and may be useful in assessing risks resulting from this catastrophe.

Flue gas discharge from cooling towers. Wind tunnel investigation of building downwash effects on ground-level concentrations

German power plants are required to meet new emission standards which limit the maximum sulfur dioxide (SOs) concentration in flue gas discharges to 400 mg m −3. To achieve this level of reduction in SO 2 concentration, wet scrubbing is necessary for large plants using lignite or hard coal. Wet scrubbing results in a significant reduction in the flue gas temperature leading to low effective stack heights. Instead of using stack gas reheating to achieve the plume rise necessary to satisfy local environmental standards, it was proposed to discharge the scrubbed flue gas from the existing natural-draft cooling towers (NDCT). This method should be effective in reducing local ground-level concentrations since NDCT-plumes are typically very buoyant (densimetric Froude number below 1 ) and normally reach considerable heights of rise. Only under strong wind conditions does the situation reverse itself. For such strong winds, the NDCT-plume is subject to tower and building downwash with the possibility of unacceptably high ground-level concentrations. For a 2700 MW e lignite-fired power plant near Cologne, a wind tunnel study was carried out to investigate the effects of tower and building downwash effects on the ground-level concentrations of SO 2 produced by discharging the scrubbed flue gas from the natural-draft cooling towers. Also, a comparison was made between the ground-level concentrations produced by the cooling tower discharge method and those produced by a traditional stack. It was found that for low and intermediate wind speeds, the groundlevel concentrations are lower for the case of the cooling tower discharge. Only for strong winds, which occur only very rarely at most German sites, did the conventional stack discharge appear to be superior.

Sulphur dioxide concentrations measured at various distances from a modern power station

Data are presented on ground-level concentrations of sulphur dioxide measured at various distances from High Marnham Power Station during the period October 1965 to September 1966. The measurements include pollution from background sources around the area, as well as from the Power Station, and the results are compared with those of previous years. As before, most of the pollution arrived from the west during fumigations, probably from distant urban sources. The pollution in the area has decreased steadily since 1963, especially in stable conditions in winter, but this decrease is due, in part, at least, to the decrease in the frequency of persistent fog situations over the same period. Short-term pollution from High Marnham alone was occasionally detected at sites between 1 2 and 17 miles (0.8 to 28 km) from source. The details given extend those published previously, M artin and B arber (1966); G illham et al. (1966). Information is given on concentrations recorded near to the source in the summer, and on possible additive effects of power station contributions.