84 Figure 6.4 Google Earth image of five days' backward trajectories at the arrival point for the month of June 2013. 85 Figure 6.5 Google Earth image of five days' backward trajectories at the arrival point for the month of July 2013.
INTRODUCTION
- General
- Problem Statement
- Objectives and Scope of the Research Work
- Organization of the Thesis
In this study, an analysis of the seasonal variation of atmospheric particles with meteorological parameters will be conducted in Khulna City. Measurement of the mass concentration and analysis of the size distribution of atmospheric particles from this urban area (seven locations) will also be carried out.
LITERATURE REVIEW
General
Air Pollution
- Local Pollution
- Regional Pollution
- Global Pollution
- Urban Pollution
- Continental Pollution
Here, Figure 2.2 presented the sources and effect of air pollution according to the National Park Service, 2010. At least three types of problems contribute to air pollution problems on a regional scale.
Sources of Air Pollution
- Natural Sources of Air Pollution
- Anthropogenic Sources of Air Pollution
- Major Sources of Air Pollution
The result of air pollution from a source which is automatically generated in nature is called natural sources of air pollution. The event of air pollution from a source, which occurred due to direct or indirect human activity, is called anthropogenic causes of air pollution.
Air Pollutants
- Classification of Air Pollutants
- According to the Origin
- According to the State of Matter
- According to the Chemical Composition
- According to the types of Releases
- Types of Air Pollutants
Depending on their origin, air pollutants can be classified as primary or secondary (Masters, 2004). Sources of air pollutants can be divided into three categories according to their release (Seinfeld, 1985).
Impact of Air Pollution in General
Colorless gas with irritating odor 1/3 from natural sources, 2/3 from human sources such as combustion of sulfur. Day by day the O3 layer is harmful due to the presence of CFC, HCFC that presence at the atmosphere.
Particulate Matter
- Size of Particulate Matter
- Sources of Particulate Matter
- Types of Particulate Matter
- Composition of Particulate Matter
- Effects of Particulate Matter
- Human Health Effect
- Wildlife Effect
- Environmental Effect
The mass concentration of fine particles to the environment is a major reason for premature deaths (Massey et. al., 2012), functional change in huma. The mass concentration of fine particles to the environment is a major reason for cardiovascular and.
Air Pollution in Bangladesh
- Air Qualities of Major Cities of Bangladesh
- Air Quality of Khulna
Air pollution is one of the major human-caused environmental problems and has recently gained prominence among environmental issues in Bangladesh (Ahmed and Hossain, 2008). Air pollution is one of the major human-caused environmental problems and has recently gained prominence among environmental issues in Bangladesh (Ahmed and Hossain, 2008). Bangladesh was ranked fourth out of 91 countries with the worst urban air quality in the latest World Health Organization (WHO, 2016) air pollution monitoring report.
The 2014 version of the Ambient Air Pollution (AAP) database consists primarily of urban air quality data from 1,600 cities from 91 countries. According to the report, nearly 90 percent of people living in cities are exposed to dangerous levels of air pollution and its consequences.
Air Quality Standards
Air Quality Data of CAMS
Meteorological Condition of Bangladesh
- Meteorological Condition of Khulna
Sometimes the minimum temperature drops below 10°C and a cold wave situation occurs mainly in the western and northern parts of the country. In the southwest monsoon season (June-September), the surface wind changes to southwesterly/southerly direction over the southern and central districts and to southeasterly direction over the northern districts of the country. As a result of occasional heavy to very heavy rainfall, landslides occur in the hilly regions in the southeast of the country.
With the onset of the monsoon, extreme summer temperatures drop significantly across the country. The annual mean wind rose indicates that wind flows from south to north most of the time in a year.
Effect of Meteorological Variables on Air Particulates
On the other hand, during March to April wind mostly flows from south and southwest to north and northeast, and during May to October it flows from south to north and southeast to northwest direction (Weer and Climate, 2015). A further study (Hien et al., 2002) revealed that fine particles are mainly controlled by wind and temperature and 60% to 74% day-to-day variation of particle concentrations can be explained by meteorological parameters and that any change in the concentration of PM2.5 is well related to pressure, relative humidity and wind speed. Different studies have shown that particulate matter is highly dependent on specific meteorological parameters (Dayan et al., 2005 and DeGaetano et al., 2004).
Several studies have been conducted to assess the extent of urban pollution in major cities of Bangladesh (Begum, 2016 and Begum et al., 2014). Although the relationship between meteorology and PM has been investigated, we still have very little information on the dependence of urban aerosol on an atmospheric parameter in major cities of Bangladesh (Islam et al., 2018).
Measuring Atmospheric Particles Concentration and Meteorological Variables by using
Although the main purpose of this study is the assessment of atmospheric particulate matter, the working principles of PM samplers for monitoring particulate matter in continuous air monitoring stations (CAMS) are described here. For the measurement of particle concentrations, this scientific principle is used for the design of beta meter instruments. According to this scientific principle, if baseline beta count is established during sampling, only the particle measurement is.
The difference between the baseline beta score and the beta score after sampling is directly proportional to the mass of PM in the sample (CASE, 2018). The instrument measures the volume of gas withdrawn through the stack/duct for each sampling interval and calculates mass concentration in the specified units (eg μg/m3) (CASE, 2018).
Measuring Atmospheric Particles Concentration by using Laser Particle Counter
Characterizing and Modal Analysis of Atmospheric Particles
Air Quality Modeling
HYSPIT Modeling
- Global Data Assimilation System (GDAS)
- HYSPLIT Back Trajectory Modeling
- Other Considerations of HYSPLIT Back Trajectory Modeling
Backtrack modeling is an oversimplification of the atmosphere in that dispersion is not considered and the potential source areas contributing to a receptor are underestimated for any given trajectory (www.arl.noaa.gov). By estimating the most likely central path over any geographic areas to supply air to any receptor at a given time, backtrack models use interpolated modeled archived 3-dimensional meteorological fields generated from short-term forecasts and observations. The minimum time step in HYSPLIT backtrack modeling is 1 minute, so the model is invalid for the transported pollutants that take less than 1 minute to move.
Important determinants such as near-surface meteorological conditions, including 10-m winds, 2-m temperatures, and surface fluxes predicted by numerical weather prediction (NWP) in the horizontal and vertical extent of the material, are the main inputs to HYSPLIT. model. Finally, the meteorological data used by HYSPLIT are interpolated bilinearly in space and linearly in time with the location and time of release of a pollutant and when predicting the subsequent diffusion of materials (Alam, 2016).
Air Quality Index
RESEARCH METHODS
- General
- Selection of Study Area
- Seasonal Variation of Atmospheric Particles with Meteorological Parameters
- Collection of Data from CAMS-5 (Khulna station)
- Find out the Seasonal Distribution and Correlation between PM 10 and PM 2.5
- Assessment of the Relationship between Atmospheric Particles and Meteorological
- Measurement of the Mass Concentration and Modal Analysis of Atmospheric Particles 44
- Characterizing and Modal Analysis of Particles Concentration Data
- Calculation of Exceedance Factor (EF) of Particulate
- Back Trajectory Calculation
- HYSPLIT Back Trajectory Modeling
- Validation of HYSPLIT Meteorology Data
- Air Quality Index Calculation
In this contrast, an almost complete dataset for atmospheric particles and meteorological parameters was found in the case of Khulna City from February 2013 to January 2014. Concentration of atmospheric particles at seven locations (one point in the city walk, one point in a residential area, one point in the industrial area, one point in the main bus stop of the city, one point in the recreational area, one point in the roadside and one point in an educational institution) in the urban area of Khulna city were measured using a HANDHELD 3016 IAQ laser particle counter, keeping it in mass concentration mode. To study the long-range transport of atmospheric particles in Khulna City, archived meteorological data was used.
The validation of HYSPLIT meteorological data file was done in this study by creating wind rose diagram from regional air quality data and another one from HYSPLIT. AQI value for this study was calculated for atmospheric particles to check the ambient air quality for this air pollutant.
ANALYSIS OF THE SEASONAL VARIATION OF ATMOSPHERIC
- General
- Daily Variation in Mass Concentrations of PM 10 and PM 2.5
- Seasonal Variation of PM 10 and PM 2.5 Mass Concentrations
- Relation between PM 10 and PM 2.5
- The Relationship between PM Mass Concentrations with Meteorological Parameters
- Air Quality Index in Monitoring Station
The correlation coefficient between them was 0.967 which means that the correlation between PM10 and PM2.5 was significant. From the Table 4.1, the correlation coefficients between wind speed and Fines (PM2.5) and Coarse (PM10-PM2.5) are respectively -0.650 and -0.502 which means that they are negatively correlated. Also the correlation coefficients between RH and Fines (PM2.5) and Coarse (PM10-PM2.5) were respectively -0.601 and -0.459 which means that they are negatively correlated.
Also the correlation between RH and Fines (PM2.5) was significant with p < 0.05, but no significant correlation was found. Significant correlation was also found between average precipitation and Fines (PM2.5) and Coarse (PM10-PM2.5) at different levels as shown in Figure 4.12.
ANALYSIS OF THE SIZE DISTRIBUTION OF ATMOSPHERIC
- General
- PM Mass Analysis
- Relationship among PM 10 , PM 2.5 and PM 1 Concentrations at Sampling Sites
- PM Size Distribution
- Exceedance Factor (EF) of PM mass concentrations in the Sampling Sites
- Air Quality Index in the Sampling Sites
Figure 5.3 also shows the time series variations of PM1, PM2.5 and PM10 concentrations for this sampling location. Variations of the daily mass concentrations of individual differential fractions and (d) 2.5 µm at the Fulbarigate site (continued…). It is noticeable from Table 5.4 that both PM2.5 and PM10 were reported at all sampling locations and the air quality was polluted at different levels.
Table 5.5 also shows that different levels of air pollution were reported for both PM2.5 and PM10 at all sampling sites. After averaging all the AQI values for the seven sampling locations, it was found to be unhealthy for PM2.5 and cautious for PM10 for Khulna city.
![Table 5.1 Mass concentrations of PM 10 , PM 2.5 and PM 1 , µg/m 3 [mean (minimum-maximum)]](https://thumb-ap.123doks.com/thumbv2/filepdfnet/10860830.0/77.918.135.862.145.295/table-mass-concentrations-pm-pm-mean-minimum-maximum.webp)
INVESTIGATION OF THE LONG RANGE TRANSPORT OF
General
Back Ward Trajectory Analysis for CAMS-5
- Transportation of Aerosols over West Bengal in CAMS-5
- Transportation of Aerosols over Bay of Bengal in CAMS-5
Air moving below 3000 meters can pick up pollution burdens from areas as it passes (Comrie, 1994). some coal mining plants and thermal power plants India. a) (b) Figure 6.1 Five days back trajectories for. The trajectory of 15 February 2013 in (Figure 6.1(d)) shows that the air mass originates in the National Park of India and after traveling Agra, Kanpur and Bihar, Google Earth view of five-day backward trajectory for the month of January 2013 showed to better understand the travel path in Figure 6.2. Air traveling below 3000 meters may get pollution burden from areas if it passes CAMS-5 due to in West Bengal from. c) Figure 6.1 Five days back trajectories.
Another trajectory for the month of October in Figure 6.3(h) appears to originate from the British Indian Ocean and is transported over Srilanka to Khulna. The trajectory for 15 August 2013 in Figure 6.3(f) shows it started from Chengam of South Indian Tamil Nadu and after traveling through Chennai and the Bay of Bengal, it reached the considered location.
Back Ward Trajectory Analysis for Sampling Sites
- Transportation of Aerosols over West Bengal in Sampling Sites
- Transportation of Aerosols over Bay of Bengal in Sampling Sites
Five-day backward trajectories at point of arrival for (a) Fulbarigate, Nirala R/A and (d) Sonadanga Bus Station Transport of aerosols across the Bay of Bengal in sampling sites. It is observed from the backward trajectory analysis that atmospheric particles Khulna City over the Bay of Bengal during the monitoring. It is observed from the backward trajectory analysis that atmospheric particles over the Bay of Bengal during the monitoring period of.
The trajectories calculated for these locations clearly indicate that all three trajectories found originate from the Bay of Bengal. The calculated trajectories for these locations clearly show that all three trajectories found have the Gulf of the observed locations.
CONCLUSIONS AND RECOMMENDATIONS
Conclusions
This study makes a preliminary analysis of PM pollution and its relation to meteorological factors in Khulna City, relevant to improve local air quality. The results of this study may aid in the development of improved particulate monitoring programs near urban areas and also establish an elementary modality data set that can be incorporated into exposure and risk assessments of atmospheric particulate matter.
Recommendation for Future Studies
Air Quality Modeling and Health Risk Assessment of Air Pollutants Generated by Khulna Power Plant, M.Sc. A comparative study of air quality index based on factor analysis and US-EPA methods for an urban environment. Monthly Air Quality Monitoring Report Month of reporting: August, 2017, Government of the People's Republic of Bangladesh, Ministry of Environment and Forests.
Ambient Air Quality in Bangladesh, Ministry of Environment Ministry of Environment, Forests and Climate Change, Government of the People's Republic of Bangladesh. Monthly Air Quality Monitoring Report Month of Reporting: August 2015 Government of the People's Republic of Bangladesh Ministry of Environment and Forests.
