Master of Science / Department of Biological & Agricultural Engineering / Ronaldo G. Maghirang / Large cattle feedlots emit considerable amounts of particulate matter (PM), including
TSP (total suspended particulates), PM[subscript]10 (PM with equivalent aerodynamic diameter of 10 μm or
less), and PM[subscript]2.5 (PM with equivalent aerodynamic diameter of 2.5 μm or less). Particulate
emissions result from pen surface disturbance by cattle hoof action, vehicle traffic on unpaved
roads and alleyways, and wind erosion. Research is needed to determine concentrations of
various size fractions, size distribution, and emission rates from various sources in feedlots. This
research was conducted to measure particle size distribution using laser diffraction method and
estimate emissions from unpaved roads and wind erosion.
Particle size distribution and concentrations of PM[subscript]10 and PM[subscript]2.5 at a commercial cattle
feedlot in Kansas (Feedlot 1) were measured over a 2-yr period. The feedlot had a capacity of
30,000 head and total pen area of 50 ha and was equipped with a sprinkler system for dust
control. Collocated low-volume samplers for TSP, PM[subscript]10, and PM[subscript]2.5 were used to measure
concentrations of TSP, PM[subscript]10, and PM[subscript]2.5 at the upwind and downwind edges of the feedlot. Dust
samples that were collected by TSP samplers were analyzed with a laser diffraction analyzer to
determine particle size distribution. Particle size distribution at the downwind edge of the
feedlot was also measured with micro-orifice uniform deposit impactor (MOUDI). The laser
diffraction method and MOUDI did not differ significantly in mean geometric mean diameter
(13.7 vs. 13.0 μm) but differed in mean geometric standard deviation (2.9 vs. 2.3). From laser
diffraction and TSP data, PM[subscript]10 and PM[subscript]2.5 concentrations were also calculated and were not
significantly different from those measured by low-volume PM[subscript]10 and PM[subscript]2.5 samplers (122 vs.
131 μg/m[superscript]3 for PM[subscript]10; 26 vs. 35 μg/m[superscript]3 for PM[subscript]2.5). Both PM[subscript]10 and PM[subscript]2.5 fractions decreased as
pen surface moisture contents increased, while the PM[subscript]2.5/PM[subscript]10 ratio did not change much with
pen surface moisture content.
Published emission models were used to estimate PM[subscript]10 emissions from unpaved roads
and wind erosion at Feedlot 1 and another nearby feedlot (Feedlot 2). Feedlot 2 had a capacity
of 30,000 head, total pen surface area of 59 ha, and used water trucks for dust control. Estimated
PM[subscript]10 emissions from unpaved roads and wind erosion were less than 20% of total PM[subscript]10
emissions obtained from inverse dispersion modeling. Further research is needed to establish the
applicability of published emission estimation models for cattle feedlots.
| Identifer | oai:union.ndltd.org:KSU/oai:krex.k-state.edu:2097/7041 |
| Date | January 1900 |
| Creators | Gonzales, Howell B. |
| Publisher | Kansas State University |
| Source Sets | K-State Research Exchange |
| Language | en_US |
| Detected Language | English |
| Type | Thesis |
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