نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه فیزیک دانشگاه زنجان و پژوهشکده تغییر اقلیم و گرمایش زمین دانشگاه تحصیلات تکمیلی علوم پایه زنجان
2 گروه علوم محیط زیست، دانشکده علوم، دانشگاه زنجان، زنجان، ایران
3 آزمایشگاه پایش آلودگی هوا، اداره کل حفاظت محیط زیست زنجان، زنجان، ایران
4 گروه زیست شناسی، دانشکده علوم زیستی، دانشگاه شهید بهشتی، تهران، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Particulate pollutants, or aerosols, are tiny solid or liquid particles suspended in the air, which are considered one of the most important air pollutants due to their environmental and health effects. On the other hand, due to aerosols optical properties in terms of absorption and scattering of solar radiation, they alter the radiation budget of the atmosphere and the Earth. Therefore, aerosols are important components in climate studies and important factors of uncertainty in climate change models.
key sources of aerosols include natural sources such as wind erosion, salt particles from ocean Particulate pollutants, or aerosols, are tiny solid or liquid particles suspended in the air, which are considered one of the most important air pollutants due to their environmental and health effects. On the other hand, due to aerosols optical properties in terms of absorption and scattering of solar radiation, they alter the radiation budget of the atmosphere and the Earth. Therefore, aerosols are important components in climate studies and important factors of uncertainty in climate change models. key sources of aerosols include natural sources such as wind erosion, salt particles from ocean waves, volcanic ash, as well as man-made sources such as fuel combustion in transportation, industry, and services. Meteorological conditions affect the emission and dispersion of particulate pollutants, so one of the main issues in the study of air pollution is how this emission occurs and the possibility of estimating and predicting the concentration of pollutants. This can be achieved air pollution models. Air pollution models are generally divided into two categories: destination-oriented models and source-oriented models.
In this work, both methods were employed. The first, is measuring the particulate pollutants concentration by sampling at different distances and geographical directions from the Zanjan specialized town of Zinc as an air pollutant source (destination-oriented model) and the second is utilizing emission data from the pollution source along with meteorological inputs such as wind and temperature in an air pollution dispersion model (source-oriented model to estimate aerosol concentrations and their dispersion patterns. For the first method, 18 air sampling stations were established at appropriate points around the Zanjan specialized town of Zinc, after a previous study and visit to the area, as a synoptic measurement network with the aim of determining the concentration of particulate pollutants. Then, for a year, air sampling was carried out simultaneously, twice a month, for 72 hours at each station. After each sampling, the filters installed in the devices were collected and transferred to the Zanjan Department of Environment air pollution measurement laboratory, and after the drying stage, they were weighed to determine the concentration of airborne particles. For the second method, first the necessary data such as the characteristics of each unit's chimney, the output values of each chimney (by measurement) were prepared with helping of Zanjan Department of Environment, as well as meteorological data through the Zanjan Department of Meteorology. Then, using source-oriented models such as the fixed and variable box model and Gaussian models for point and surface sources, the concentration values of particulate pollutants were determined and their distribution was examined.
The results showed that the measured concentrations of particulate pollutants decrease with distance according to the concentration changes diagram and their classification maps with distance from the specialized settlement. By comparing the above values with the primary and secondary standards of the particulate pollutants, it is observed that respectively 4 and 7 stations out of 18 stations in the measurement network are above the permissible limit, and the remaining stations are below the permissible limit of the standard. Observation and study of pollution rose wind and distribution patterns derived from the Gaussian model also confirm the decrease in aerosols with distance and show that aerosol concentration values and their dispersion depend on meteorological variables, especially wind direction and speed. Given the location of Zanjan city in the northeast of the Zanjan Specialized Town of Zinc and the prevailing northwest wind, the concentration of particles in the central strip of Zanjan city extending from southwest to northeast is high, and the further away from the strip, the lower the particle concentration.
کلیدواژهها [English]
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