Seasonal Variations in PM_(10) and Associated Chemical Species in Jiuxian Mountain in Fujian Province
- 环境生态－已发表论文 
于2011年3月~2012年1月期间在福建德化县九仙山气象站采集大气了PM_(10)样品,分析了九仙山大气PM_(10)中水溶性离子及二元羧酸,; 对其季节分布与来源进行了探讨。结果表明,九仙山大气PM_(10)、水溶性无机离子和有机二元羧酸的季节分布规律较为接近,都表现为春季的浓度显著高于; 其它季节,但9种二元羧酸对PM_(10)的贡献(0.51% 0.41%)显著低于水溶性离子(18.07 %; 8.73%)。其中,水溶性离子组成以NO_3~-和SO_4~(2-)的浓度为最高,其次为Na~+和NH_4~+;阴离子与阳离子当量浓度、NH_4; ~+与SO_4~(2-)当量浓度,以及NH_4~+与NO_3~-当量浓度之间都存在显著正相关关系。有机二元羧酸的组成以乙二酸的浓度为最高,占测量; 二元羧酸总量的75%左右,且随碳数增加呈逐渐递减趋势;来源特征比值(丙二酸/丁二酸、己二酸/壬二酸)、MODIS火点图及后向轨迹图显示,有机二元; 羧酸主要来自大气二次化学反应过程,生物质燃烧的直接贡献很小。PM_(10) samples were collected at the top of Jiuxian Mountain in Fujian; Province from March 2011 to January 2012 and were analyzed for inorganic; water-soluble ions and dicarboxylic acids to investigate their seasonal; variations and sources. The results showed that PM_(10) and its; associated species exhibited much higher levels in the spring than those; in other seasons but the total contribution of the nine species of; dicarboxylic acids to PM_(10) (0.51% 0.41%) was significantly lower; than that of the water-soluble ions (18.07% 8.73%). The water-soluble; ions were characterized by the highest concentrations of SO_4~(2-) and; NO_3~-,followed by Na~+ and NH_4~+. Significant positive correlations; were observed between cation and anion equivalents,as well as between; NH_4~+ and SO_4~(2-) or NO_3~-equivalents. Individual dicarboxylic acid; showed a monotonically decreasing trend with increasing carbon number in; which oxalic acid accounted for approximately 75% of the total; dicarboxylic acids. Characteristic ratios of malonic acid to succinic; acid and adipic acid to azelaic acid,MODIS fire spots,and backward; trajectories showed that dicarboxylic acids mainly originated from; secondary reactions in the atmosphere and that the direct contributions; of open biomass burning to dicarboxylic acid concentrations were; negligible.