鼎湖山大气气态总汞含量和变化特征的初步研究

利用高时间分辨率自动大气测汞仪(Tekran,2537B),于2009.10—2010.4对珠三角背景点鼎湖山大气气态总汞(TGM)进行了连续7个月的野外观测.结果表明,鼎湖山地区TGM的年均含量为(5.54±2.89)ng·m-3,含量明显高于全球大气汞含量的背景值(1.5～2.0ng·m-3)和国内部分地区的背景值,表明该地区大气受到了一定程度的汞污染.监测期间,4月TGM含量最高,11月最低.日变化特征显示白天TGM浓度比晚上高,属典型白天控制型.鼎湖山地区TGM主要受珠三角的区域污染影响,TGM含量变化与大气中NO2、SO2的相关性分析和与用电需求变化对比表明,珠三角人为源(尤其是燃煤的汞排放)对鼎湖山大气TGM有较大的贡献.

Preliminary study of the concentration and variation characteristics of total gaseous mercury in Dinghu Mountain Area

From October 2009 to April 2010, total gaseous mercury (TGM) in Dinghu Mountain, a background area of the Pearl River Delta (PRD), was continuously monitored using high-resolution automatic atmospheric mercury vapor analyzer (Tekran 2537B). Average concentration of TGM was (5.54±2.89) ng·m^-3 with a range from 1.87 to 29.94 ng·m^-3, which was much higher than those reported in global and domestic background areas (1.5~2.0 ng·m^-3). This finding suggested mercury pollution in the atmosphere. The highest concentration of TGM was found in April, and the lowest in November during the sampling period. Meanwhile, a diurnal TGM distribution pattern indicated that higher concentration of TGM was observed in daytime. The TGM in Dinghu Mountain area was mainly affected by regional atmospheric pollution from the PRD. Based on the relationship between TGM and the concentrations of NO₂ and SO₂, as well as the analysis of TGM and the variation of electric power demand, we concluded that TGM in this area was contributed from mercury-related anthropogenic sources, especially coal-fired emission.