文献类型：期刊文献

英文题名：Formation pathways and source apportionments of inorganic nitrogen-containing aerosols in urban environment: Insights from nitrogen and oxygen isotopic compositions in Guangzhou, China

作者：Xi, Dan[1,2] Xiao, Yihua[3] Mgelwa, Abubakari Said[4,5] Kuang, Yuanwen[1,6]

第一作者：Xi, Dan

通信作者：Kuang, YW[1]

机构：[1]Chinese Acad Sci, Guangdong Prov Key Lab Appl Bot, South China Bot Garden, Xingke Rd 723, Guangzhou 510650, Peoples R China;[2]Jiangxi Prov & Chinese Acad Sci, Lushan Bot Garden, Jiujiang 332900, Peoples R China;[3]Chinese Acad Forestry, Res Inst Trop Forestry, Guangzhou, Peoples R China;[4]Chinese Acad Sci, Inst Appl Ecol, CAS Key Lab Forest Ecol & Management, Shenyang 110016, Liaoning, Peoples R China;[5]Mwalimu Julius K Nyerere Univ Agr & Technol, Coll Nat Resources Management & Tourism, POB 976, Musoma, Tanzania;[6]Chinese Acad Sci, Key Lab Vegetat Restorat & Management Degraded Eco, South China Bot Garden, Guangzhou 510650, Peoples R China

年份：2023

卷号：309

外文期刊名：ATMOSPHERIC ENVIRONMENT

收录：;EI(收录号：20232714342478);Scopus(收录号：2-s2.0-85163736829);WOS:【SCI-EXPANDED(收录号:WOS:001020522200001)】；

基金：This work was financially supported by the National Natural Science Foundation of China (No. 41703068) and the Open Research Project of Guangdong Provincial Key Laboratory of Applied Botany (No. AB2015002) .

语种：英文

外文关键词：PM2.5 pollution; Nitrogen isotope; Oxygen isotope; Source apportionment; Aerosol formation pathways; Guangzhou

摘要：Air quality issues caused by PM2.5-induced persistent extreme haze episodes have become increasingly serious in urban environments in recent years. Secondary water-soluble inorganic sulfate (SO42-), nitrate (NO3-) and ammonium (NH4+) ions are the major components of PM2.5. However, the contributions of inorganic nitrogen species, especially nitrate, to PM2.5 have greatly increased during haze episodes in many cities in China. Therefore, better understanding of their emission sources and formation pathways holds the key to controlling urban PM2.5 pollution more efficiently and effectively. In this study, water-soluble ionic characteristics and isotopic compositions and sources of NH4+ and NO3-, as well as NO3- formation pathways were determined in PM2.5 aerosol samples collected in Guangzhou, China, during 2015-2018. The PM2.5 concentrations varied from 30.5 to 189.8 mu g.m(-3) and their mean values were highest in spring (111.1 mu g.m(-3)) and lowest in summer (63.5 mu g.m(-3)). The delta N-15-NH4+ and delta N-15-NO3- values ranged from +4.5 to +20.2 parts per thousand and from +4.8 to +14.8 parts per thousand, respectively, with their mean values being highest in winter (14.0 parts per thousand and 9.5 parts per thousand, respectively) and lowest in summer (10.4 parts per thousand and 7.1 parts per thousand, respectively). The seasonal delta N-15 variability was mainly attributed to isotopic equilibrium fractionation, and partly due to the changes in NH3 and NOx sources. The average delta O-18-NO3- value of 63.0%, ranging seasonally from +58.6% in summer to +68.0% in spring, suggests that NO2 +.OH pathway played a vital role (70.3-85.9 parts per thousand) in NO3- formation. The Bayesian isotope mixing model results revealed fossil fuel combustion sources as dominant sources of atmospheric NH3 and NOx. This study suggests that more effort should be devoted to reduce NH3 and NOx from combustion-related processes and highlights the importance of delta O-18-NO3- analysis for exploring variations of nitrate formation pathways in urban atmospheres.