| 英文摘要 |
The investigation of ambient particulate matters at four monitoring stations, Zhu-Shan, Taixi, Xin-Gang, and Dou-Liu, in the Central and Yun-Jia Area was performed in this project. Water-soluble anions and cations, metal, and trace elements of particulate samples were analyzed to understand chemical compositions, characteristics and the source contribution. The load of crustal, seasalt, vehicles, industrial emission and secondary aerosols in ambient were identified by Principal Components Analysis. It showed that road traffic was important at Xin-Gang, Dou-Liu and Zhu-Shan. The industrial contribution however appeared much more significant influence at Taixi and Dou-Liu area.
Severe PM10 episodes happened on November 2nd, 2009 and on March 21st~22nd, 2010. The former one was coaused by aeolian dust and the later was the sand storm episiode. And huge amounts of suspended particles resulted in very worse air quality. During the aeolian dust event, high levels of Al, Fe, Ca, Mg, Ca2+, Mg2+ were detected and the increase amount of Fe from segment of the Choshui River showed quite significant at the sites of Taixi and Dou-Liu. Great influence of severe wind erosion was also proved by rich soil and dust components at these two sites and at Xin-Gang area. During the sand storm event, element Al, Fe, Ca, and Ca2+, F- ions were the specific specis enormously increased.
At the sampling area, events of high levels of particulate matters were highly associated with poor dispersion. Poor air quality caused by high-level PM2.5 happened more frequently than by PM10. The accumulation of secondary NO3- was effective during the PM2.5 events. The PM events were different in area. High levels of PM2.5, or ozone episodes with high PM2.5 level were usually happened at Zhu-Shan area. At Taixi area, high level of PM2.5 was the main condition during a PM episode, and PM10 events with higher PM2.5 was the second. While at Xin-Gang, the PM10 event with high PM2.5 level was the main case and the high-level PM2.5 case was the next. At Dou-Liu area, high levels of PM2.5 were detected very often, and the PM10 events with high PM2.5 were the second. Both cases made Dou-Liu with most PM events observed amoung the four sampling sites. Our study showed that the high level of PM2.5 has become the main case during PM events in the Central and Yun-Jia Area.
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