| 英文摘要 |
The project was carried out from Feb. 19th to Dec. 20, 2013. The main work items of this project include: manual monitoring and sampling of fine particulates, source estimation and a comparison with monitoring results.
(I) Manual monitoring, sampling, and source estimation of fine particulates in Kinmen
According to the sampling results of each season, the autumn and winter reported the highest average mass concentration, and summer got the lowest level. During the sampling period, both the local and outside pollution source spread by the transport mechanism, which is the influence of the prevailing wind, so that the concentration of PM2.5 appeared more higher at downwind sampling site. Estimated from wind rose chart analysis, it shows that the outside pollution accounted for 71% to 98%, and 71% on average. In particular, the proportion of outside pollution was more higher in the autumn and winter.
The analysis found that PM2.5 species in each season were mainly the secondary aerosols, accounting for about 30-60%. The primary aerosols accounted for about 20-30%, with EC and OCpri being the most important components, and others was about 20%. A Chemical Mass Balance (CMB) model was used to simulate possible pollution sources. The results show that the primary traffic source and secondary ammonium sulfate were generally the main pollution sources at each sampling site, followed by the elements of the Earth’s crust. It is worth noting that the agricultural waste burning also occupy a certain proportion.
(II) Comparative analysis of PM2.5 concentration between routine manual survey station and automatic survey station
Comparing with the monitoring data of 2013, the results reveal that the PM2.5 annual mean concentrations of Hsinchu, Miaoli, Yunlin, Chiayi, Tainan, Hualien, Taitung, and Kinmen were higher in 2014. On the other hand, except for the North Air Basin, H.T. Air Basin, and Yilan Air Basin, the 24-hour PM2.5 values in the other Air Basins were lower in 2014. According to the statistics, the national average of PM2.5 annual mean concentration is 23.6 µg/m3, and the average 24-hour PM2.5 value is 59.7µg/m3 in 2014. However, further analysis of the monitoring data shows that all of the Air Basin cannot meet the air quality standards, excluding H.T. Air Basin.
On the whole, among the seven Air Basin, the Y.C.T Air Basin reported the highest PM2.5 annual mean concentrations and 24-hour PM2.5 values, which were 31.8µg/m3 and 81.3µg/m3 respectively. The second highest was Central Air Basin, whose PM2.5 annual mean concentrations was 27.0 µg/m3 and 24-hour PM2.5 values was 70.5µg/m3. Among the monitor station, the Chiayi station reported the highest PM2.5 annual mean concentrations and 24-hour PM2.5 values, which were 34.7µg/m3 and 85.2µg/m3 respectively. The second highest was Douliou station, whose PM2.5 annual mean concentrations was 34.1µg/m3 and 83.9µg/m3 values was 70.5µg/m3. The Kinmen station's PM2.5 annual mean concentrations and 24-hour PM2.5 values were 32.8µg/m3 and 81.4µg/m3.
In addition, the PM2.5 exceeding day of Kinmen was 35 days in 2014, which was 11 days less than 2013. This result illustrated that the county improvement strategy achieved initial success, and the improvement rate was 24%.
(III) Formulating the county's PM2.5 Control Strategy
To sum up, the results suggest that the main pollution sources of PM2.5 in the County are the primary traffic source and secondary ammonium sulfate, followed by elements in the Earth’s crust and sea salt and spray from nature. However, the County is small in size, the retention period of SOx and NOx emissions is too short, resulting in the limited production of the secondary aerosols. Its pollution load is much lower compared to the sources such as China’s Xiamen, Zhangzhou and Quanzhou; it is speculated that most of the ammonium sulfate and primary traffic source came through long-distance transmission from China, except for its own pollutant discharge.
For Kinmen County, the PM2.5 pollution formed and transmitted from the outside sources is belonging to the uncontrollable sources. For this issue, we suggests that the county should understand what are the difficulties and challenges each other is facing now through cross-strait exchanges, and establish a dialogue mechanism and cooperation mode of associated pollution control so that the outside pollution problem could be improved effectively. On the other hand, the PM2.5 formed by the precursor reaction of direct emissions can be classified as controllable sources. Therefore, in stationary sources part, this project suggests to strengthen the stationary source control measures in the short-term, put the laws and regulations into effect, promote the Taipower to use cleaner fuels, formulate autonomous regulations of catering Management as well as retrofit Catering's control equipment comprehensively. In mobile sources part, the county should to eliminate the two-stroke motorbike acceleratingly, subsidy low-pollution vehicles, promote bicycle rental system. Furthermore, to enhance the street dust sweeping, strengthen control and inspection of construction site, improve bare land, reduce ghost money are the goal of fugitive emission control to strive toward. To sum up, all the control strategies mentioned above are feasible to carry out in Kinmen county, which could reduce PM2.5 or its precursors including SO2、NOx、VOCs effectively.
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