燃煤电厂区域颗粒物及颗粒物汞分布特征研究

Pollution characteristics of particulate matter and particulate mercury near a coal-fired power plant

对东南沿海平原地区某燃煤电厂不同方位距离的9个采样点进行为期9个月的大气颗粒物采集,以PM2.5、PM10为对象,研究了颗粒物与颗粒物汞的时空分布,探讨了燃煤电厂排放对周边大气颗粒物与颗粒物汞分布的影响.结果表明:①本研究区PM2.5平均浓度为78.10μg·m^-3,其中颗粒物汞平均浓度为294.88 pg·m^-3;PM10平均浓度为114.48μg·m^-3,其中颗粒物汞平均浓度为363.41 pg·m^-3,均高于海内外众多城市.②冬季颗粒物、碳组分及颗粒物汞的浓度远高于春、夏、秋三季,冬季燃煤量大、逆温等气象因素及远距离污染物传输均造成当地冬季颗粒物累积.③大气颗粒物汞浓度随距电厂距离的增加先增加后降低,最大浓度范围为电厂W-NW方向1.3~2.5 km处.④各采样点均受到多种污染源共同影响,以燃煤尘为主,餐饮油烟、机动车尾气、生物质燃烧和扬尘次之,燃煤电厂对周边区域环境大气可吸入颗粒物主要影响区域为W-NW方向1.3~2.5 km.

During 9 months, PM2.5 and PM10 samples were collected at 9 sampling sites in different directions and distances of a coal-fired power plant on the southeast coast of China. This study had investigated the seasonal and spatial distribution of particulate matter and particulate mercury(Hg^p), and discussed the impact of power plant emissions on the surrounding atmosphere. The main results are as follows: ① The average concentration of PM2.5 and PM10 were 78.10 μg·m^-3 and 114.48 μg·m^-3, and the average concentration of Hg^p among them were 294.88 pg·m^-3 and 363.41 pg·m^-3, respectively. These were much higher than those in many cities in the world.② The highest concentration of particulate matter, carbon components and Hg^p were observed in winter, much higher than that in other seasons, probably because of the highest coal consumption, the meteorological factors such as inversion temperature and the transmission of long-distance pollutants. ③The concentration of Hg^p increased first and then decreased with the increase of the distance from the power plant, and the maximum concentration appeared on 1.3~2.5 km in the W-NW direction of the power plant. ④ Each sampling site was affected by a variety of pollution sources, burning coal dust was ranking the first, with lampblack, motor vehicle exhaust, biomass burning dust followed, and the main affected area of coal-fired power plant was 1.3~2.5 km in the W-NW direction.