|Amante-Orozco, Alejandro - COL DE POSTGRAD, MEXICO|
Submitted to: International Conference on Aeolian Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 14, 2002
Publication Date: July 22, 2002
Citation: AMANTE-OROZCO, A., ZOBECK, T.M. CLAY AND CARBONATE EFFECT ON FINE DUST EMISSIONS AS GENERATED IN A WIND TUNNEL. PROCEEDINGS OF THE ICAR5/GCTE-SEN JOINT.2002. INTERNATIONAL CENTER OF ARID AND SEMIARID LAND STUDIES TEXAS TECH UNIVERISTY, LUBBOCK, TX Pub No. 02-2 pp. 83-86 Interpretive Summary: Frequently, human activities and the force of the wind give rise to blowing dust. Dust created in this way is called "fugitive dust". Since field measurement of fugitive dust is difficult, considerable effort is now directed toward developing equipment and techniques to create and analyze these fine airborne particles in the lab. The fugitive dust we are most interested in is called PM10. PM10 is particulate matter less than 10 microns in size, about 1/10th the diameter of a human hair. In this study, we used a wind tunnel where wind erosion was reproduced to evaluate the effect of soil clay and calcium carbonate (CaCO3) content on aerosol PM10 created from eight agricultural soils of the Southern High Plains near Lubbock, Texas. Clay and carbonate are normal soil physical properties thought to have an effect on the amount of dust produced during a dust storm. We found that the amount of PM10 dust increased as soil clay content decreased and carbonate content increased. Carbonate had a greater effect on dust produced than clay content. The soils with the lowest amount of carbonate (<3%) and highest amount of clay (>20%) produced the lowest amount of PM10 dust of the soils tested.
Technical Abstract: A growing concern for health effects and climatic impact of airborne dust has motivated a number of studies focusing on sediment properties and meteorological conditions that influence dust emissions. Determination of the capacity of different soil types to produce PM10 emissions and identification of the causes for variations in PM10 production among them is critical to improve the estimation of PM10 emission by wind erosion. PM10 is particulate matter having aerodynamic diameter </- 10 µm. Wind erosion is the main source of these types of dust emissions in the Southern High Plains of Texas. In this study, we used a suction-type wind tunnel where wind erosion was reproduced to evaluate the effect of soil clay and calcium carbonate (CaCO3) content on aerosol PM10 production from eight agricultural soils of the Southern High Plains near Lubbock, Texas. Soil clay and CaCO3 content significantly affected airborne PM10 emissions from soil aggregates. Airborne PM10 concentrations increased as soil clay content decreased and soil CaCO3 content increased, with CaCO3 having the greatest impact. Consequently, soils from agricultural fields in the Southern High Plains of Texas that would produce the highest PM10 concentrations have more than 3% by weight CaCO3 content and less then 20% clay. Conversely, the lowest PM10 concentrations were observed in soils with low CaCO3 content (<3%) and high clay content (>20%). PM10 production from abraded soil aggregates was found to be significantly different among soils.