An Instrument for Real Time Speciation of Water Soluble Tracers in Atmospheric Particulate MatterEPA Grant Number: R832835
Title: An Instrument for Real Time Speciation of Water Soluble Tracers in Atmospheric Particulate Matter
Investigators: Weber, Rodney J. , Schauer, James J. , Shafer, Martin M.
Institution: Georgia Institute of Technology , University of Wisconsin Madison
EPA Project Officer: Chung, Serena
Project Period: May 1, 2006 through April 30, 2010
Project Amount: $492,354
RFA: Continuous Measurement Methods for Particulate Matter Composition (2005) RFA Text | Recipients Lists
Research Category: Particulate Matter , Air , Air Quality and Air Toxics
The overall objective of the proposed project is to develop, validate, and employ a cost-effective real time instrument that can measure water-soluble components of urban aerosols and will be used to support source apportionment efforts and human health studies. The proposed instrument will be designed for simplicity and autonomous operation and is intended to function in parallel with a real time particle mass analyzer (such as a TEOM), a real time particulate matter ECOC analyzer, and a Speciation Trends Sampler (STN).
The proposed instrument would measure the following species at a time resolution of one hour:
- Water soluble inorganic ions (Sulfate, Nitrate, and Ammonium)
- Water soluble crustal elements (Calcium, Potassium, and Sodium)
- Water soluble organic carbon (WSOC)
- Water soluble trace metals (Chromium (VI), Copper, Iron (II), and Manganese (II))
The collection and analytical methods that will be used for the proposed instruments directly build on methods that have been employed by the project team and will be integrated to yield an instrument that can be operated at air quality monitoring sites to measure:
- The hourly contribution of secondary inorganic aerosol to PM concentrations
- The hourly contribution of water-soluble organic carbon (WSOC) to particulate matter concentrations. WSOC is predominately associated with wood smoke and secondary organic aerosol (SOA) in urban environments.
- The hourly contribution of sodium from sea spray and road salt to PM concentrations.
- The hourly fingerprint of water soluble crustal elements associated with resuspended dust, wood burning, and industrial sources.
- The hourly concentrations of toxic metals that can be used as source tracers.
The instrument developed under this project will enable measurements of these compounds to be readily obtained at state and local air quality monitoring sites. The data generated can be used along with STN data to identify sources of particulate matter and sources of toxic components of particulate matter. In addition, these measurements will provide a valuable data stream for health studies and air pollution model validation. This instrument will require limited operating and maintenance oversight and will be suitable for monitoring stations that are operated by a wide range of state and local agencies. The proposed project will develop and validate the instrument prototype and will demonstrate the operability and data analysis opportunities of the instrument during a year-long study.