Environ. Sci. Technol. 2011, 45, 658–665
Optical Remote Sensing To Quantify Fugitive Particulate Mass Emissions from Stationary Short-Term and Mobile Continuous Sources: Part I. Method and Examples KE DU* Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China MARK J. ROOD Department of Civil and Environmental Engineering, University of Illinois, 205 North Mathews Avenue, Urbana, Illinois, United States ELLSWORTH J. WELTON Goddard Space Flight Center, National Aeronautics and Space Administration, Greenbelt, Maryland, United States RAVI M. VARMA Department of Physics, National Institute of Technology Calicut, Calicut 673601, India RAM A. HASHMONAY Environ, 88 VilCom Circle, Suite 185, Chapel Hill, North Carolina 27514, United States BYUNG J. KIM AND MICHAEL R. KEMME Construction Engineering Research Laboratory, U.S. Army Engineer Research and Development Center, 2902 Newmark Drive, Champaign, Illinois 61826-9005, United States
Received June 3, 2010. Revised manuscript received October 15, 2010. Accepted November 14, 2010.
The emissions of particulate matter (PM) from anthropogenic sources raise public concern. A new method is described here that was developed to complete in situ rapid response measurements of PM mass emissions from fugitive dust sources by use of optical remote sensing (ORS) and an anemometer. The ORS system consists of one ground-based micropulse light detection and ranging (MPL) device that was mounted on a positioner, two open path-Fourier transform infrared (OP-FTIR) spectrometers, and two open path-laser transmissometers (OP-LT). An algorithm was formulated to compute PM light extinction profiles along each of the plume’s cross sections that were determined with the MPL. Sizespecific PM mass emission factors were then calculated by integrating the light extinction profiles with particle mass extinction efficiencies (determined with the OP-FTIRs/OP-LTs) and the wind’s speed and direction. This method also quantifies the spatial and temporal variability of the plume’s PM mass concentrations across each of the plume’s cross sections. Example results from three field studies are also described to * Corresponding author e-mail:
[email protected]; phone: +86-5926190767. 658
9
ENVIRONMENTAL SCIENCE & TECHNOLOGY / VOL. 45, NO. 2, 2011
demonstrate how this new method is used to determine mass emission factors as well as characterize the dust plumes’ horizontal and vertical dimensions and temporal variability of the PM’s mass concentration.
1. Introduction The emissions of particulate matter (PM) from anthropogenic sources raise public concern due to their contribution to the degradation of ambient visibility (1). The Regional Haze Rule was adopted during 1999 to protect visibility in class I areas (2), such as national parks, forests, and wilderness areas (3). There is a need to better quantify PM emissions from anthropogenic sources by developing emission factors that can then be used in emission inventories and dispersion models. These inventories can then be used to make more informed decisions about managing PM emissions to meet Federal ambient air quality standards. Fugitive dusts are generated by anthropogenic activities such as construction, mining, material handling, vehicle movement, and select military activities. There are a few methods that quantify fugitive dust emissions with a spatial scale ranging from tens to hundreds of meters. Flux tower measurements determine mass concentration profiles by using multiple extractive point monitors that are mounted at select heights on 1-3 towers. PM emission fluxes are then calculated on the basis of the resulting mass concentration profile, the wind’s speed and direction, and the duration of the plume event (4). A tracer technique was also developed to simulate the dispersion of PM10 by use of SF6. The mass emission rate of particles with diameters
