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1.
Lime has become the world’s leading reagent for use in the treatment of both water and air pollution and, after sulfuric acid, is the No. 2 basic chemical in commercial use. As a result, the production capacities of the manufacturing plants are being rapidly expanded to meet the increasing demand for liming materials. This paper describes the achievements of the lime industry in developing methods of handling and controlling the various finely divided products which they produce. An extensive survey provides useful data on the availability and performance of many of the control devices that are currently in use, and an analysis is made of the operating efficiencies and costs of this equipment. The environmental control programs which are currently underway in this industry are described and an evaluation is made of these programs. The ultimate goals that are believed to be attainable are presented from the standpoint of emission control from individual processes as well as from operating plant complexes. While the paper deals primarily with practical operating and engineering aspects of the subject, some information is also included on methods of tests and the monitoring systems that are in use.  相似文献   

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Community odours in the vicinity of an oil refinery and petrochemical industrial area were studied by an observer network throughout an entire year. Odour episodes occurred during 0.86 percent of the time of the study. Odour reports increased closer to the refinery. Within a range of 12.5 km, more than 50 percent of the odours were estimated to originate from the refinery. The most typical odour was that of reduced sulphur compounds (35.2 percent of all observations). Odour episodes occurred during low wind velocities and high humidity. Odours were most frequent during January-April, and were usually reported early in the morning. The odours were evidently due to the general operation of the plants, as no single activity or in-plant factor could be identified as the source of the odours.  相似文献   

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Hourly concentrations of ozone were measured by the chemiluminescence method during the summer of 1971 in the vicinity of 33 cities. A listing was made of the percent of time the National Air Quality Standard for photochemical oxidants was violated. At 4 selected cities the daytime and nighttime average concentrations were related to wind directions showing the direction to source areas. Another set of tables and graphs was used to show the source directions for high concentrations (equal to or above 120 µg/m3) and disregarding the times of more usual or background concentrations. Numerous occasions of high ozone concentrations occurred when wind directions were apparently from areas with low concentrations of the known precursors. Because of this, other sources of ozone were considered such as thunderstorms and the transport of ozone for long distances. Examples of ozone concentrations during thunderstorms or related to long distance transport are cited.  相似文献   

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Potential health risks of exposure to emissions of a yeast and penicillin production plant were investigated by measuring viable particles and protein contents of particles in ambient air. The results showed a clear decrease of the downwind number of yeast colonyforming units with increasing distance from the source. Upwind the number of yeast colony-forming units was zero. Identification showed that nearly all yeast were of the species Saccharomlces cerevisiae. Such a trend could not be found for the total number of colony-forming units (yeasts, molds, and bacteria) although the upwind concentration was slightly lower than the downwind concentration. The downwind protein concentration was significantly elevated compared to the upwind concentration.  相似文献   

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Abstract

Two mathematical models of the atmospheric fate and transport of mercury (Hg), an Eulerian grid–based model and a Gaussian plume model, are used to calculate the atmospheric deposition of Hg in the vicinity (i.e., within 50 km) of five coal–fired power plants. The former is applied using two different horizontal resolutions: coarse (84 km) and fine (16.7 km). More than 96% of the power plant Hg emissions are calculated with the plume model to be transported beyond 50 km from the plants. The grid–based model predicts a lower fraction to be transported beyond 50 km: >91% with a coarse resolution and >95% with a fine resolution. The contribution of the power plant emissions to total Hg deposition within a radius of 50 km from the plants is calculated to be <8% with the plume model, <14% with the Eulerian model with a coarse resolution, and <10% with the Eulerian model with a fine resolution. The Eulerian grid–based model predicts greater local impacts than the plume model because of artificially enhanced vertical dispersion; the former predicts about twice as much Hg deposition as the latter when the area considered is commensurate with the resolution of the grid–based model. If one compares the local impacts for an area that is significantly less than the grid–based model resolution, then the grid–based model may predict lower local deposition than the plume model, because two compensating errors affect the results obtained with the grid–based model: initial dilution of the power plant emissions within one or more grid cells and enhanced vertical mixing to the ground.  相似文献   

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Abstract

Many areas in Jordan suffer from elevated levels of coarse particulate matter (PM10). One potentially significant source of the observed PM is the resuspension of road dust in the vicinity of limestone quarries. To obtain data to assess the impact from this source, PM10 road dust resus-pension factors near Abusiiah, a town to the north east of Amman surrounded by many quarries and brick factories, were measured. Measurements included PM10 mass, particle size distributions, wind speed, and wind direction.The results showed that PM10 concentrations could be as high as 600 µg/m3, and most of the airborne PM is in the coarse fraction. Loading trucks play a major role in resus-pending road dust, with an observed PM10 emission rate of >6000 mg/km.  相似文献   

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Air monitoring data for a calendar year at one of the TVA power plants has been used to evaluate the appropriateness of the Sutton, the Bosanquet and Pearson, and the USPHS-TVA atmospheric dispersion models to predict ground level concentrations of sulfur dioxide from emission and meterological data. Aerometric data included one half hourly average sulfur dioxide concentrations, recorded by four Thomas autometers, and the necessary meterological parameters for the solving of atmospheric dispersion models. Based on these meterological parameters and observed plume rise data, over 4000 one half hourly average maximum and minimum expected ground line sulfur dioxide concentrations were predicted for each of the above dispersion models by the use of computer techniques. The plant is a line source; however, an empirical correction was applied to emission data to reduce them to emissions for an equivalent point source. The predicted sulfur dioxide levels for each of the dispersion models were compared to the measured levels throughout the year. Three different sets of diffusion coefficients were applied to the Sutton model and successful predictions, according to a criterion utilizing an acceptable range of concentration, varied from 66 to 93%. The Bosanquet and Pearson model produced successful predictions 90% of the time, while the USPHS-TVA model was successful 94% of the time.Unsuccessful predictions were primarily overestimates.  相似文献   

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In 1988 a study was undertaken in the vicinity of Tulsa, Oklahoma to determine the characteristics, composition, and relative concentrations of the oil field emissions of volatile organic compounds (VOC). Forty grab samples (10-minute) using stainless steel canisters were collected from five different stages of crude oil production over an 80-day period (August-October). The samples were analyzed at the Tulsa City-County Health Department’s laboratory, using cryogenic preconcentration, gas chromatographic separation, and flame ionization detection. The six prevalent components of the oil field emissions were ethane, propane, 2- methyl propane, n-butane, 2-methylbutane, and n-pentane with propane predominating. The composition is unique with higher amounts of propane than ethane and is different from natural gas which has more abundant ethane. Decreases occurred in the amounts of light compounds, namely, ethane and propane from well heads through refinery tanks. The bulk of these losses appeared to be at the well heads and gathering tanks.  相似文献   

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Abstract

Before a community-wide woodstove changeout program, a chemical mass balance (CMB) source apportionment study was conducted in Libby, MT, during the winter of 2003–2004 to identify the sources of fine particulate matter (PM2.5) within the valley. Results from this study showed that residential woodstoves were the major source, contributing approximately 80% of the ambient PM2.5 throughout the winter months. In an effort to lower the ambient PM2.5, a large woodstove changeout program was conducted in Libby from 2005 to 2007 in which nearly 1200 old woodstoves were changed out with cleaner burning models. During the winter of 2007–2008, a follow-up CMB source apportionment study was conducted to evaluate the effectiveness of the changeout. Results from this study showed that average winter PM2.5 mass was reduced by 20%, and woodsmoke-related PM2.5 (as identified by the CMB model) was reduced by 28% when compared with the pre-changeout winter of 2003– 2004. These results suggest that a woodstove changeout can be an effective tool in reducing ambient levels of PM2.5 in woodstove-impacted communities.  相似文献   

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It has long been recognized that information on particle size distributions in atmospheric aerosals is necessary for meaningful evaluations of potential health hazards. Such information is also important in establishing particulate sources, transport, transformations, and sinks, especially in combination with elemental and chemical data. While instruments exist to collect size segregated samples of particulates, they are too complex and expensive to encourage use of multiple units in field situations.  相似文献   

16.
Linear regression of high volume air sampler data and various meteorological parameters was used to determine a suspended particulate air pollution climatology for Albany, NY. A new method for exhibiting associations between wind direction and pollutant levels using correlation coefficients is presented. Correlations between wind direction distribution frequency and other meteorological parameters is employed to help explain differences in correlations for direction with suspended particulate levels. Results show that high particulate concentrations correlate well with southerly wind flow throughout the study area, regardless of relative location of receptor to local sources. This suggests that ambient background concentrations inherent in different air masses more consistently affected suspended particulate levels than did the diffusion from local sources during the study period. Maximum particulate advection occurs under conditions of good mixing of the boundary layer and moderate wind speeds and is enhanced further in the absence of removal processes such as rainout and washout. Trajectory analysis of selected days indicates a definite relationship between path and origin of the wind flow and regional average particulate concentration.  相似文献   

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Abstract

The present work focuses on the characterization of air quality and the identification of pollutant origin at a former mining site in the city of Lavrion, Greece. A historical metallurgy complex is reused for establishing the Lavrion Technology and Cultural Park (LTCP). A serious problem with this is the severe soil contamination that resulted from intensive mining and metallurgical activities that has taken place in the greater area for the past 3000 years. Among other consequences, surface-polluted depositions, rich in heavy and toxic metals, are loose and easily wind-eroded, resulting in transportation of particu-late matter (PM) in the surrounding atmosphere. On the other hand, there are a number of industries relatively close to the site that are potential sources of PM air pollution. The current study deals with the collection and analysis of PM10 samples with respect to their concentration in heavy metals, such as Pb, Cd, Cu, Fe, Zn, Mn, Cr, and Ni. Though not a heavy metal, As also is included. Furthermore, the source of these elements is verified using statistical correlation and by calculating enrichment factors (EFs), considering that some substances are certainly of contaminated soil origin. Results show that PM10 and element concentrations are relatively low during winter but significantly increase during summer. Fe, Pb, Zn, Mn, and Cu may be considered of contaminated soil origin, while As, Ni, Cd, and Cr are very much enriched with respect to contaminated soil, indicating another possible source attributed to the adjacent industrial plants.  相似文献   

18.
Trace metals collected on filter paper by a hi-volume air sampler for 24 hours were analyzed using the X-ray fluorescence method. A gamma ray exciting source (241Am) and a bremsstrahlung exciting source (147Pm) were both used to produce the X-rays, the latter being more efficient. For the samples collected in Dayton, several metals were detected, viz.: Ti, Fe, Cu, Zn, Pb, Cd, and Sn. Elements in the periodic table between Ti and Cs were seen to have a sensitivity limit of 0.5 micrograms/m3 of air.  相似文献   

19.
分别运用传统的中流量颗粒物采样器和RP1400 a自动测尘仪,对空气中颗粒物(TSP和PM10)进行同步采样检测,结果表明,两种方法的检测结果存在着明显的系统偏差,前者的检测结果较后者偏高。  相似文献   

20.
Particulate size distributions were obtained in the effluent gases from three steam generating boilers of a power station employing mechanical, steam, and air systems for heavy fuel atomization. Samples were obtained with an eight-stage cascade impactor. The air atomized burner produced the lowest particulate loading, the greatest percentage of particulates by weight in the submicron range, and particulates with the lowest combustible content.  相似文献   

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