胡珊瑚,吴晓晨,徐文帅,谢荣富,冼爱丹,杨朝晖.三亚城区PM2.5中水溶性离子特征与来源分析[J].环境科学学报,2021,41(7):2540-2549
三亚城区PM2.5中水溶性离子特征与来源分析
- Characteristics and source analysis of water-soluble ions in PM2.5 in Sanya
- 基金项目：海南省重大科技计划项目（No.ZDKJ202007）；海南省财政专项（No.ZC2018-196）
- 摘要：基于2019年三亚城区站点PM2.5中水溶性离子在线观测数据，分析了水溶性离子的质量浓度水平、不同时间尺度和不同PM2.5浓度下的特征，探讨了气象因子对离子组分的影响，通过主成分分析（PCA）解析来源.结果表明：2019年三亚城区总水溶性离子（TWSI）质量浓度为8.173 μg·m-3，占ρ（PM2.5）的58.4%，各离子质量浓度大小依次为：ρ（SO42-） > ρ（NO3-） > ρ（K+） > ρ（NH4+） > ρ（Na+） > ρ（Cl-） > ρ（Ca2+） > ρ（F-） > ρ（Mg2+） > ρ（NO2-），其中二次离子SO42-、NO3-、NH4+（SNA）和K+为主要离子组分，占总水溶性离子的80.0%，海盐粒子Na+及Cl-之和占比为14.7%，且与风速呈显著正相关；TWSI季节浓度变化特征明显，秋季最高，春冬季次之，夏季最低，主要与秋冬季风速较大、主导风向转为东北风，易受外来传输有关；SO42-在各个季节均是浓度及占比最高的离子，硫氧化率（SOR）的日均值均大于0.1，存在显著的SO2向SO42-转化的过程；PCA分析结果表明三亚城区水溶性离子主要受海洋源、二次源及生物质燃烧源的影响.
- Abstract：Based on the online observation data of water-soluble ions (WSI) in PM2.5 in Sanya city site in 2019, the mass concentration levels of WSI, the characteristics of different time scales and different concentrations of PM2.5 were analyzed, and the influence of meteorological factors on WSI were discussed. The sources of WSI were analyzed through principal component analysis (PCA). The results show that the total water-soluble ions (TWSI) mass concentration in urban area of Sanya in 2019 is 8.173 μg·m-3, accounting for 58.4% of ρ(PM2.5). The mass concentration of WSI is sorted in the following order: ρ(SO42-) > ρ(NO3-) > ρ(K+) > ρ(NH4+) > ρ(Na+) > ρ(Cl-) > ρ(Ca2+) > ρ(F-) > ρ(Mg2+) > ρ(NO2-). Secondary ion (SO42-, NO3- and NH4+, SNA) and K+ are the main ions components, accounting for 80.0% of the TWSI. The sum of Na+ and Cl- of sea salt particles account for 14.7%, which was significantly positively correlated with wind speed. The highest concentration of TWSI occurred in autumn, followed by spring, winter, and summer. It is mainly caused by the high wind speed and northeast wind in autumn and winter, which is susceptible to external transport. SO42- is the dominant component in each season, and the daily value of sulfur oxidation rate (SOR) exceeds 0.1, indicating a significant conversion process of SO2 to SO42-. PCA analysis results show that WSI in Sanya city are mainly affected by marine sources, secondary sources and biomass combustion sources.
