2015 Progress Report: Understanding the Hygroscopic Properties of Black Carbon/Organic Carbon Mixing States: Connecting Climate and Health Impacts of Anthropogenic Aerosol

EPA Grant Number: R835040
Title: Understanding the Hygroscopic Properties of Black Carbon/Organic Carbon Mixing States: Connecting Climate and Health Impacts of Anthropogenic Aerosol
Investigators: Asa-Awuku, Akua
Institution: University of California - Riverside
EPA Project Officer: Chung, Serena
Project Period: October 1, 2011 through September 30, 2014 (Extended to September 30, 2016)
Project Period Covered by this Report: October 1, 2014 through September 30,2015
Project Amount: $449,925
RFA: Black Carbon's Role In Global To Local Scale Climate And Air Quality (2010) RFA Text |  Recipients Lists
Research Category: Global Climate Change , Climate Change , Air

Objective:

The objective of the study is to understand properties of black carbon (BC) containing aerosol that is well mixed with organic hygroscopic material. The mixtures of BC and organic material significantly affect water uptake and cloud nucleating ability. To address these scientific questions, the PI has: 1) designed a novel apparatus to control and modify BC/organic carbon (OC) aerosol mixing states for subsequent testing, 2) addressed and identified unique and viable on-line and off-line measurement techniques to characterize BC/OC water-uptake and droplet growth of diverse aerosol sources, and 3) initiated a testing protocol to measure the in-situ cloud droplet ability of mixed BC/OC aerosol from alternative fuel emissions and advanced vehicle technologies. 

Progress Summary:

The PI’s research group has investigated the water nucleating properties of BC containing aerosol from two distinct sources: biomass burning and vehicular emissions. The contribution of BC to the total biomass burning aerosol mass decreases during aging and photochemistry as additional organic material is formed during controlled aging environmental chamber experiments. The changes in fractal nature and effective particle density have been observed and have been shown to affect cloud nucleation predictions. In addition, the organic mixture has been shown to be surface active; hence, though black carbonaceous material often is considered insoluble, the mixture with surface active organic composition can facilitate cloud nucleation, and promote CCN activity in biomass burning systems. This work now is published in leading scientific journals in the field. The PI and her research group also have developed a viable on-line technique to characterize the water nucleating properties of BC-aerosol compositions. The technique has been applied to vehicular studies that investigate the emission from alcohol (ethanol–E10 and butanol–B15) gasoline fuel blends in commercial light duty vehicles. BC concentrations are measured for light duty vehicles operated on the federal test procedure and unified testing cycle. To date, two distinct vehicle technologies have been tested; port-fuel injection and gasoline direct injection vehicles. The BC concentrations have been compared to insoluble mass fractions inferred with the online technique. Lastly, The PI has designed and developed a mixing apparatus to control and modify BC/OC mixing states. BC emissions data from the vehicle studies have been submitted to journals and manuscripts currently are in review. The initial CCN mixing state measurements with known aerosol compounds have been conducted with the mixing state apparatus. Results are being compiled and will be submitted for publication in 2016. The work also has resulted in three Ph.D. theses. 

Future Activities:

Th PI and team will submit articles on the mixing apparatus studies in the laboratory environment/organic mixtures. Remaining results from vehicular emissons are slated for publication in the final report. We plan to continue with work as proposed. An emphasis will be placed on completing and conducting experiments with the unique mixing apparatus. More data will be gathered from the apparatus and more complex BC containing aerosol particles will be introduced to the device. 


Journal Articles on this Report : 7 Displayed | Download in RIS Format

Other project views: All 34 publications 9 publications in selected types All 9 journal articles
Type Citation Project Document Sources
Journal Article Giordano MR, Short DZ, Hosseini S, Lichtenberg W, Asa-Awuku AA. Changes in droplet surface tension affect the observed hygroscopicity of photochemically aged biomass burning aerosol. Environmental Science & Technology 2013;47(19):10980-10986. R835040 (2013)
R835040 (2014)
R835040 (2015)
R835040 (Final)
  • Abstract from PubMed
  • Full-text: ES&T-Full Text HTML
    Exit
  • Abstract: ES&T-Abstract
    Exit
  • Other: ES&T-Full Text PDF
    Exit
  • Journal Article Giordano MR, Asa-Awuku A. Rebuttal to correspondence on "Changes in droplet surface tension affect the observed hygroscopicity of photochemically aged biomass burning aerosol". Environmental Science & Technology 2014;48(3):2084-2085. R835040 (2014)
    R835040 (2015)
    R835040 (Final)
  • Abstract from PubMed
  • Full-text: ES&T-Full Text HTML
    Exit
  • Abstract: ES&T-First Page Preview
    Exit
  • Other: ES&T-Full Text PDF
    Exit
  • Journal Article Giordano M, Espinoza C, Asa-Awuku A. Experimentally measured morphology of biomass burning aerosol and its impacts on CCN ability. Atmospheric Chemistry and Physics 2015;15(4):1807-1821. R835040 (2014)
    R835040 (2015)
    R835040 (Final)
  • Full-text: ACP-Full Text PDF
    Exit
  • Abstract: ACP-Abstract
    Exit
  • Other: ResearchGate-Abstract & Full Text PDF
    Exit
  • Journal Article Karavalakis G, Short D, Vu D, Villela M, Russell R, Jung H, Asa-Awuku A, Durbin T. Regulated emissions, air toxics, and particle emissions from SI-DI light-duty vehicles operating on different iso-butanol and ethanol blends. SAE International Journal of Fuels and Lubricants 2014;7(1):183-199. R835040 (2014)
    R835040 (2015)
    R835040 (Final)
  • Full-text: University of California-Full Text PDF
    Exit
  • Abstract: SAE International-Abstract
    Exit
  • Journal Article Karavalakis G, Short D, Vu D, Villela M, Asa-Awuku A, Durbin TD. Evaluating the regulated emissions, air toxics, ultrafine particles, and black carbon from SI-PFI and SI-DI vehicles operating on different ethanol and iso-butanol blends. Fuel 2014;128:410-421. R835040 (2014)
    R835040 (2015)
    R835040 (Final)
  • Full-text: ScienceDirect-Full Text HTML
    Exit
  • Abstract: ScienceDirect-Abstract
    Exit
  • Other: ScienceDirect-Full Text PDF
    Exit
  • Journal Article Short D, Giordano M, Zhu Y, Fine PM, Polidori A, Asa-Awuku A. A unique online method to infer water-insoluble particle contributions. Aerosol Science and Technology 2014;48(7):706-714. R835040 (2012)
    R835040 (2014)
    R835040 (2015)
    R835040 (Final)
  • Full-text: Taylor&Francis-Full Text PDF
    Exit
  • Abstract: Taylor&Francis-Abstract
    Exit
  • Journal Article Short D, Vu D, Durbin TD, Karavalakis G, Asa-Awuku A. Particle speciation of emissions from iso-butanol and ethanol blended gasoline in light-duty vehicles. Journal of Aerosol Science 2015;84:39-52. R835040 (2014)
    R835040 (2015)
    R835040 (Final)
  • Full-text: ScienceDirect-Full Text HTML
    Exit
  • Abstract: ScienceDirect-Abstract
    Exit
  • Other: ScienceDirect-Full Text PDF
    Exit
  • Supplemental Keywords:

    atmospheric pollution, black carbon, climate, aerosol-indirect effect, tropospheric aerosol, mixing state, particle hygroscopicity 

    Relevant Websites:

    UC-Riverside Aerosol-cloud Climate Research Group Exit

    Progress and Final Reports:

    Original Abstract
    2012 Progress Report
    2013 Progress Report
    2014 Progress Report
    Final Report