Iron solubility in fine particles associated with secondary acidic aerosols in east China

Research output: Contribution to journalArticlepeer-review


  • Yanhong Zhu
  • Weijun Li
  • Qiuhan Lin
  • Qi Yuan
  • Lei Liu
  • Jian Zhang
  • Yinxiao Zhang
  • Longyi Shao
  • Hongya Niu
  • Shushen Yang

Colleges, School and Institutes

External organisations

  • School of Earth Sciences, Zhejiang University
  • China University of Mining and Technology
  • Hebei University of Engineering
  • Zhongyuan University of Technology


Soluble iron (FeS) in aerosols contributes to free oxygen radical generation with implications for human health, and potentially catalyzes sulfur dioxide oxidation. It is also an important external source of micronutrients for ocean ecosystems. However, factors controlling FeS concentration and its contribution to total iron (FeT) in aerosols remain poorly understand. Here, FeS and FeT in PM2.5 was studied at four urban sites in eastern China from 21 to 31 December, 2017. Average FeT (869–1490 ng m−3) and FeS (24–68 ng m−3) concentrations were higher in northern than southern China cities, but Fe solubility (%FeS, 2.7–5.0%) showed no spatial pattern. Correlation analyses suggested %FeS was strongly correlated with FeS and PM2.5 instead of FeT concentrations. Individual particle observations confirmed that more than 65% of nano-sized Fe-containing particles were internally mixed with sulfates and nitrates. Furthermore, there was a high correlation between sulfates or nitrates/FeT molar ratio and %FeS. We also found that the sulfates/nitrates had weaker effects on %FeS at RH < 50% than at RH > 50%, suggesting RH as indirect factor can influence %FeS in PM2.5. These results suggest an important role of chemical processing in enhancing %FeS in the polluted atmosphere.


Original languageEnglish
Article number114769
JournalEnvironmental Pollution
Early online date10 May 2020
Publication statusPublished - Sep 2020


  • polluted air, bulk aerosol analysis, individual particles analysis, Fe solubility, atmospheric acidification processing, Environmental Monitoring, Humans, Solubility, Sulfates/analysis, Aerosols/analysis, Iron/analysis, Nitrates/analysis, Air Pollutants/analysis, China, Ecosystem, Particulate Matter/analysis, Cities