Atmospheric ammonia and its impacts on regional air quality over the megacity of Shanghai, China.
Atmospheric ammonia and its impacts on regional air quality over the megacity of Shanghai, China.
复制标题
中国上海特大城市大气氨及其对区域空气质量的影响
DOI：
10.1038/srep15842
复制
发表时间：
2015-10-30
影响因子：
4.6
通讯作者：
Zhou B
中科院分区：
文献类型：
--
作者：
Wang S;Nan J;Shi C;Fu Q;Gao S;Wang D;Cui H;Saiz-Lopez A;Zhou B
大气氨（NH3）在生态系统和全球氮循环中具有重要的作用，并对二次粒子的形成有重要贡献，因此具有重要的环境意义。在这里，我们报告了长期连续测量NH3在不同的位置（即城市，工业和农村）在上海，中国，这提供了一个前所未有的画像大气NH3的时空特征和周围的这个特大城市。除了点排放源外，来自或经过富氨地区（如农村和工业场所）的空气质量增加了上海市区内观测到的NH3浓度。显着的高频NH3的变化，在工业现场测量，表明瞬时附近的工业排放峰值。此外，我们观察到NH 4 +/（NH 4 ++NH3）和硫酸盐-硝酸盐-铵（SNA）气溶胶，PM2.5质量浓度之间的强正指数相关性，这意味着相当大的贡献的气体到颗粒的氨转化为SNA气溶胶形成。较低的温度和较高的湿度条件下，被发现有利于气态氨转化为颗粒态铵，特别是在秋季。虽然NH3目前还没有包括在中国的空气污染前体物的排放控制政策，我们的研究结果突出了监测气态氨和改善其排放清单在上海和周边地区的紧迫性和重要性。
Atmospheric ammonia (NH3) has great environmental implications due to its important role in ecosystem and global nitrogen cycle, as well as contribution to secondary particle formation. Here, we report long-term continuous measurements of NH3at different locations (i.e. urban, industrial and rural) in Shanghai, China, which provide an unprecedented portrait of temporal and spatial characteristics of atmospheric NH3in and around this megacity. In addition to point emission sources, air masses originated from or that have passed over ammonia rich areas, e.g. rural and industrial sites, increase the observed NH3concentrations inside the urban area of Shanghai. Remarkable high-frequency NH3variations were measured at the industrial site, indicating instantaneous nearby industrial emission peaks. Additionally, we observed strong positive exponential correlations between NH4+/(NH4++NH3) and sulfate-nitrate-ammonium (SNA) aerosols, PM2.5mass concentrations, implying a considerable contribution of gas-to-particle conversion of ammonia to SNA aerosol formation. Lower temperature and higher humidity conditions were found to favor the conversion of gaseous ammonia to particle ammonium, particularly in autumn. Although NH3is currently not included in China’s emission control policies of air pollution precursors, our results highlight the urgency and importance of monitoring gaseous ammonia and improving its emission inventory in and around Shanghai.