| 淄博2021年元宵节PM2.5水溶性离子污染特征 |
| 摘要点击 3477 全文点击 1065 投稿时间：2021-05-26 修订日期：2021-07-11 |
| 查看HTML全文
查看全文 查看/发表评论 下载PDF阅读器 |
| 中文关键词 污染过程 元宵节 烟花爆竹 形成机制 液态水含量(LWC) 颗粒物pH |
| 英文关键词 pollution episode Lantern Festival fireworks formation mechanism liquid water content (LWC) particle pH |
|
| 中文摘要 |
| 基于在线离子数据，对淄博2021年元宵节一次PM2.5污染过程进行成因分析，分析了水溶性离子组分污染特征，探讨了二次无机离子（SNA）的形成机制，并对比分析了污染前后颗粒物液态水含量（LWC）及pH值的变化特征.结果表明，元宵节前污染期间（T1）和元宵节夜间污染期间（T2），ρ（WSIIs）分别为46.83 μg·m-3和71.18 μg·m-3，分别是清洁时段的2.3倍和3.6倍.其中，T1时段SNA的增长倍数（2.7倍）大于PM2.5的增长倍数（2.1倍），可见SNA浓度增加是引起T1时段PM2.5浓度上升的主因；而T2时段Cl-、K+和Mg2+浓度增加显著，分别是清洁时段的4.0、14.8和16.5倍，反映出烟花爆竹燃放对T2时段PM2.5浓度快速增长的影响.污染期间LWC为49.37 μg·m-3，是清洁期的2.9倍；T1时段LWC主要受RH和NH4+的影响，T2时段LWC还受到Mg2+的影响.淄博污染期间pH值为4.79±1.54，较清洁期下降了0.14.T1时段pH值受SO42-和NH4+的综合影响使其较之清洁期有所下降；T2时段pH值可能受烟花爆竹燃放排放的K+、Cl-和Mg2+影响，导致其pH有所上升.形成机制分析表明，此次污染过程中SO42-主要由非均相水解生成，而NO3-则主要通过均相反应生成.综合来看，此次污染过程中，元宵节前PM2.5浓度增加主要由SNA生成增加导致，元宵节夜间主要由烟花爆竹燃放导致. |
| 英文摘要 |
| Based on the online ion data, we have analyzed the cause of a PM2.5 pollution episode, which happened during the Lantern Festival in Zibo in 2021. The pollution characteristics of water-soluble ion components were analyzed, the formation mechanism of secondary inorganic ions (SNA) was discussed, and the changes in the liquid water content (LWC) and pH value of particulate matter before and after pollution were comparatively analyzed. The results showed that the pollution period before the Lantern Festival (T1) and the pollution period at night (T2) ρ(WSIIs) during the Lantern Festival were 46.83 μg·m-3 and 71.18 μg·m-3, respectively, which were 2.3 times and 3.6 times that of the cleaning period, respectively. Among them, the growth multiple of SNA during the T1 period was greater[ρ(NO3-) was 2.9 times, ρ(SO42-) was 2.8 times, and ρ(NH4+) was 2.4 times] than the growth multiple of PM2.5 (2.1 times), which showed that the increase in SNA concentration during the T1 period was the main reason for the increase in PM2.5 concentration. Furthermore, the Cl-, K+, and Mg2+ concentrations, which were 4.0, 14.8, and 16.5 times that of the cleaning period, respectively, increased significantly during the T2 period, indicating that the fireworks and firecrackers caused the rapid increase in the PM2.5 concentration during the T2 period. The LWC during the pollution period was 49.37 μg·m-3, which was 2.9 times that of the cleaning period. LWC was mainly affected by RH and NH4+ during the T1 period and was also affected by Mg2+ during the T2 period. The average pH during the pollution period in Zibo was 4.79±1.54, which was 0.14 lower than that during the cleaning period. The pH during the T1 period was affected by the combined effects of SO42- and NH4+, which made it decrease 0.53 compared to that during the cleaning period. The pH value during the T2 period may be affected by the K+, Cl-, and Mg2+ emitted from the fireworks and firecrackers, causing the pH to increase 0.65 compared to that during the cleaning period. The formation mechanism showed that SO42- was mainly generated by heterogeneous hydrolysis during the pollution episode, whereas NO3- was mainly generated by homogeneous reactions. On the whole, during the pollution episode, the increase in PM2.5 concentration before the Lantern Festival was mainly caused by the increase in SNA concentration, and the increase the night of the Lantern Festival was mainly caused by setting off fireworks and firecrackers. |
|
|
|
