Highly time-resolved characterization of water-soluble inorganic ions in PM2.5 in a humid and acidic mega city in Sichuan Basin, China
Highly time-resolved characterization of water-soluble inorganic ions in PM2.5 in a humid and acidic mega city in Sichuan Basin, China
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中国四川盆地潮湿酸性特大城市 PM2.5 中水溶性无机离子的高度时间分辨表征
DOI：
10.1016/j.scitotenv.2016.12.048
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发表时间：
2017
影响因子：
9.8
通讯作者：
Yang FuMo
中科院分区：
文献类型：
--
作者：
Tian Mi;Wang HuanBo;Chen Yang;Zhang LeiMing;Shi GuangMing;Liu Yuan;Yu JiaYan;Zhai ChongZhi;Wang Jun;Yang FuMo
为研究重庆市雾区和酸性地区水溶性无机离子的特征，采用2004年12月24日-2005年12月30日的气象资料，（Na+、K+、NH 4+、Ca 2+和Mg 2+）和六种阴离子利用现场气体和气溶胶成分监测仪，采集了2015年12月18日至2016年3月20日重庆市冬季PM2. 5中F-、Cl-、NO2-、NO3-、PO 43-和SO 42-的含量。WSII小时总浓度平均为38.5 μg/m3，占PM2.5质量浓度的57%。二次无机气溶胶（NH 4+、NO3−和SO 42 −）是主要的WSII，占WSII质量的91%。与十年前相比，SO 42 −浓度下降了31%，但NO3−水平增加了一倍，这可能表明移动的源对细颗粒物污染的贡献比固定源大得多。NO3−来源于NH3和HNO 3的流通量到硫酸盐颗粒和/或从云过程中的关键途径在研究区的潮湿条件下。水分和/或相对湿度可能是控制硝酸盐形成的重要因素。轨迹分析表明，重庆市气溶胶污染主要由本地排放造成。
To investigate the characteristics of water-soluble inorganic ions (WSIIs) in Chongqing, a well-known foggy and acid region in southwestern China, hourly real-time concentrations of five cations (Na+, K+, NH4+, Ca2 +, and Mg2 +) and six anions (F−, Cl−, NO2−, NO3−, PO43 −, and SO42 −) in PM2.5during winter (from Dec. 18, 2015 to Mar. 20, 2016) in Chongqing were collected by applying In-situ Gas and Aerosol Compositions Monitor. The hourly total concentration of WSIIs was 38.5 μg/m3on average, accounting for 57% of PM2.5mass concentration. Secondary inorganic aerosols (NH4+, NO3−, and SO42 −) were dominant WSIIs, accounting for 91% of WSIIs mass. Compared to ten years ago, SO42 −concentrations were decreased by 31% but NO3−levels were doubled, likely indicative of sharply enhanced contribution to fine particle pollution from mobile sources over stationary sources. NO3−originated from the current fluxes of NH3and HNO3onto sulfate particles and/or from in-cloud processes were critical pathways under humid conditions in the study area. Water content and/or RH might be important factors controlling nitrate formation. Trajectory analysis manifested that aerosol pollutions in Chongqing were mostly caused by local emissions.