Factors affecting the ambient physicochemical properties of cerium-containing particles generated by nanoparticle diesel fuel additive use

Research output: Contribution to journalArticlepeer-review

Authors

  • Brett Gantt
  • Shamia Hoque
  • Kathleen M. Fahey
  • Robert D. Willis
  • K. Max Zhang
  • David A. Jefferson
  • Markus Kalberer
  • Kristin L. Bunker
  • Joseph M. Conny
  • Prakash V. Bhave
  • Jason P. Weinstein
  • Havala O T Pye

Colleges, School and Institutes

External organisations

  • U.S. Environmental Protection Agency
  • Department of Land Resources and Environmental Sciences
  • Department of Environmental Sciences / Center of Excellence in Environmental Studies, King Abdulaziz University, PO Box 80203, Jeddah, 21589, Saudi Arabia
  • Department of Civil and Environmental Engineering
  • National Exposure Research Laboratory
  • Office of Research and Development
  • University of South Carolina
  • Sibley School of Mechanical and Aerospace Engineering
  • Cornell University
  • University of Cambridge
  • RJ Lee Group Inc.
  • Materials Measurement Science Division
  • National Institute of Standards and Technology
  • International Centre for Integrated Mountain Development (ICIMOD)

Abstract

Despite the use of cerium oxide nanoparticles (nCe) in some regions as a diesel fuel additive, the physicochemical properties of the resulting exhaust particles in the ambient atmosphere are not well known. The mixing state of ceria with other exhaust particles is one such physicochemical property that has been shown to potentially affect ecosystem/human health. In this study, cerium-containing particles associated with an nCe additive were collected in the laboratory and in Newcastle-upon-Tyne, UK where the local bus fleet uses the Envirox nCe additive. Electron microscopy of laboratory-generated exhaust samples indicated both individual ceria and soot particles (external mixture) and ceria contained within soot agglomerations (internal mixture). Low ambient concentrations prevented quantification of the ceria particle mixing state in the atmosphere; therefore, a multicomponent sectional aerosol dynamic model was used to predict the size, chemical composition, and mixing state of ceria particles as a function of distance from an idealized roadway. Model simulations predicted that most ceria particles remain nonmixed in the ambient atmosphere (300 m downwind from the roadway) due to slow coagulation, with the mixing rate most sensitive to the ceria content of emitted nuclei-mode particles and the particle concentration upwind of the road. Although microscopy analysis showed both external and internal mixtures of ceria and soot in freshly emitted particles, the ambient mass concentration, and size distribution of ceria particles predicted by the model was insensitive to the emitted mixing state.

Details

Original languageEnglish
Pages (from-to)371-380
Number of pages10
JournalAerosol Science and Technology
Volume49
Issue number6
Publication statusPublished - 3 Jun 2015