Particle Size Distribution of PM Emitted from Cotton Harvesting

Poor air quality in some areas of the US has caused regulators to increase regulatory pressure on sources of air pollution. Historically, cotton producers have not been targeted by regulators to reduce emissions through mandatory implementation of particulate matter (PM) control strategies. However, the use of inaccurate PM emission factors for field operations (including cotton harvesting) has resulted in the identification of agricultural operations as a significant source of PM pollution in California. Little work has been conducted to accurately determine emission factors for PM10 and PM2.5 from cotton harvesting operations. Furthermore, no research has been conducted to characterize the physical parameters of the PM emissions from cotton harvesting in terms of the The authors are solely responsible for the content of this technical presentation. The technical presentation does not necessarily reflect the official position of the American Society of Agricultural and Biological Engineers (ASABE), and its printing and distribution does not constitute an endorsement of views which may be expressed. Technical presentations are not subject to the formal peer review process by ASABE editorial committees; therefore, they are not to be presented as refereed publications. Citation of this work should state that it is from an ASABE meeting paper. EXAMPLE: Author's Last Name, Initials. 2006. Title of Presentation. ASABE Paper No. 06xxxx. St. Joseph, Mich.: ASABE. For information about securing permission to reprint or reproduce a technical presentation, please contact ASABE at [email protected] or 269-429-0300 (2950 Niles Road, St. Joseph, MI 49085-9659 USA). particle size distribution (PSD), particle density, and PM composition. Therefore, the work presented in this manuscript describes the results of an investigation into the physical parameters of the PM < 100 micrometers (μm) contained in seed cotton samples taken from harvesting operations in Texas and New Mexico. It is anticipated that the PM < 100 μm contained in harvested seed cotton samples will provide a representative sample from which to make inferences on the physical parameters of the PM emitted from the harvesting operation. PM was air-washed from seed cotton samples taken from 2 locations in Texas and New Mexico and was analyzed for particle density, PSD, and PM composition. The results of the particle density analysis indicate that PM air washed from the seed cotton samples has a particle density on the order of 2.24 ± 0.175 g/cm. Significant differences in the particle density of the PM air washed from seed cotton samples were detected by location. PSD analyses indicate that the mean percent mass of the PM<100 μm for PM10 and PM2.5 are on the order of 27.5 ± 4.91% and 8.1 ± 2.34%, respectively. No significant differences were observed between the samples by location or harvester type for percent PM10 or PM2.5. A compositional analysis of the PM air washed from the seed cotton samples indicates that soil material and plant material likely account for 78.7 ± 14.6% and 21.3 ± 14.6% of the PM <100 μm contained in the seed cotton samples, respectively.