Search

Quantification of emissions of fugitive particulate matter (PM) into the atmosphere from military training operations is of interest by the United States Department of Defense. A new range-resolved optical remote sensing (ORS) method was developed to quantify fugitive PM emissions from puff sources (i.e., artillery back blasts), ground-level mobile sources (i.e., movement of tracked vehicles), and elevated mobile sources (i.e., airborne helicopters) in desert areas that are prone to generating fugitive dust plumes. Real-time, in situ mass concentration profiles for PM mass with particle diameters <10 μm (PM10) and <2.5 μm (PM2.5) were obtained across the dust plumes that were generated by these activities with this new method. Back blasts caused during artillery firing were characterized as a stationary short-term puff source whose plumes typically dispersed to <10 m above the ground with durations of 10-30 s. Fugitive PM emissions caused by artillery back blasts were related to the zone charge and ranged from 51 to 463 g PM/firing for PM10 and 9 to 176 g PM/firing for PM2.5. Movement of tracked vehicles and flying helicopters was characterized as mobile continuous sources whose plumes typically dispersed 30-50 m above the ground with durations of 100-200 s. Fugitive PM emissions caused by moving tracked vehicles ranged from 8.3 to 72.5 kg PM/km for PM10 and 1.1 to 17.2 kg PM/km for PM2.5, and there was no obvious correlation between PM emission and vehicle speed. The emission factor for the helicopter flying at 3 m above the ground ranged from 14.5 to 114.1 kg PM/km for PM10 and 5.0 to 39.5 kg PM/km for PM2.5, depending on the velocity of the helicopter and type of soil it flies over. Fugitive PM emissions by an airborne helicopter were correlated with helicopter speed for a particular soil type. The results from this range-resolved ORS method were also compared with the data obtained with another path-integrated ORS method and a Flux Tower method. [ABSTRACT FROM AUTHOR]

Visual Determination of the Opacity of Emissions from Stationary Sources (Method 9) is a reference method established by U.S. Environmental Protection Agency (EPA) to quantify plume opacity. However, Method 9 relies on observations from humans, which introduces subjectivity. In addition, it is expensive to teach and certify personnel to evaluate plume opacity on a semiannual basis. In this study, field tests were completed during a "smoke school" and a 4-month monitoring program of plumes emitted from stationary sources with a Method 9 qualified observer to evaluate the use of digital photography and two computer algorithms as an alternative to Method 9. This Digital Optical Method (DOM) improves objectivity, costs less to implement than Method 9, and provides archival photographic records of the plumes. Results from "smoke school" tests indicate that DOM passed six of eight tests when the sun was located in the 140° sector behind one of the three cameras, with the individual opacity errors of 15% or less and average opacity errors of 7.5% or less. DOM also passed seven of the eight tests when the sun was located in the 216° sector behind another camera. However, DOM passed only one of the eight tests when the sun was located in the 116° sector in front of the third camera. Certification to read plume opacity by a "smoke reader" for 6 months requires that the "smoke reader" pass one of the smoke school tests during smoke school. The average opacity errors and percentage of observations with individual opacity errors above 15% for the results obtained with DOM were lower than those obtained by the smoke school trainees with the sun was located behind the camera, whereas they were higher than the smoke school trainee results with the sun located in front of the camera. In addition, the difference between plume opacity values obtained by DOM and a Method 9 qualified observer, as measured in the field for two industrial sources, were 2.2%. These encouraging results demonstrate that DOM is able to meet Method 9 requirements under a wide variety of field conditions and, therefore, has potential to be used as an alternative to Method 9. [ABSTRACT FROM AUTHOR]