TAMU Cotton Engineering & Management

CAFO Research Impacts
  • PM10 Emission Factor for Free Stall Dairies – Dr. Parnell and Barry Goodrich
   This study is funded under contract to UC Davis. Our initial findings were that the PM10 emission factor for free-stall dairies should be approximately 5 lbs per 1000hd per day. The California Air Resources Board (CARB) had been using a much larger number (135 lbs/1000hd/d). We determined that the 135 lbs/1000hd/d emission factor was derived from the old AP-42 TSP emission factor that was in error.  In spite of the fact that our preliminary emission factor is not final, the CARB is using an emission factor between 5 and 10 lbs/1000hd/d.
  • Ammonia and PM10 Emission Factors for Broiler Operations – Dr. Lacey and Jarah Redwine
   Ms. Redwine and Dr. Lacey reported ammonia and PM10 emission factors that were dramatically different than those reported by EPA. One of the unique findings was that the EPA ammonia emission factor was an order of magnitude greater that was possible based upon the nitrogen consumed by the birds. The PM10 emission factor was greatly affected by the particle size distribution (PSD) of the dust emitted by the ventilation system. The MMD of the dust was approximately 25 micrometers AED which resulted in a small fraction of PM10.
  • Protocol for Determining Emission Factors of PM10 and Ammonia from Animal Feeding Operations with the Animals Confined to Ventilated Housing - Dr. Lacey and Jarah Redwine
   Dr.Lacey and Redwine developed a new methodology for determining emission factors from enclosed livestock buildings. They measured the concentration in the house and determined the emission rate based upon accurate measurements of ventilation rate and measured concentrations. Data collection followed a statistical experimental plan and the resulting emission rates included an estimate of error. They also included a propagation of errors analysis for the process which highlighted the key factors for gravimetric analysis of particulate matter. The resulting emission factor should be more accurate because of the new protocol.
  • A New Dispersion Modeling Procedure (FTAM) for Predicting Downwind Concentrations of PM10 from Low-Level Point Sources (LLPS) [LLPS include Cotton Gins, Grain Elevators, Feed Mills, etc.] – Dr Shaw, Dr. Brad Fritz, Linda Williams, Greg Zwicke, and John Wanjura
   The Industrial Source Complex Short Term, version 3 (ISCST3) model is the EPA recommended dispersion model for predicting downwind concentrations from sources. The problems we have encountered using ISCST3 is that it over-estimates downwind concentrations. We have conducted an in-depth analysis and have learned that a correction can be made in the science that will more appropriately account for wind direction changes in the ISCST3 model. The resulting downwind estimates of the 24-hour concentrations are reduced by a factor of 2.5. If we can get EPA approval to use this approach, the resulting impact upon SAPRA permitting of cotton gins, grain elevators and feed mills will be significant.
  • Aerial Pollutant Emissions from Confined Animal Buildings – Dr. John Sweeten, Dr. Jacek Koziel, Dr. Bok-Haeng Baek.
   The project goal is to determine baseline emission rates for swine finish barns in Texas and evaluate the differences in emissions due to season of year, time of day, growth cycle of the animals, and building management. Texas A&M University has been continuously measuring emissions of NH3, H2S, CO2, PM-10, and odor from mechanically-ventilated, confined swine finishing houses since November 2002. The swine finishing houses are located nearly 100 miles from Texas A&M Agricultural Research and Extension Center in Amarillo, Information from this research will provide producers, technical assistance providers, regulators, and compilers of emission inventories with accurate baseline information.
  • Improving Measurements of Dust and Ammonia Emissions from Confined Animal Buildings – Dr. Jacek Koziel and Dr. John Sweeten.
   Dust and ammonia emissions have risen sharply in importance as issues confronting both the swine and poultry industries. The first objective of this project is to supplement the larger APECAB project by periodically measuring TSP (total suspended particulates) to compliment the continuous measurement of PM10 (dust particles under 10 mm in diameter). This will be accomplished using (1) gravimetrical integration of mean mass concentration of TSP over regular time periods, and (2) continuous monitoring of TSP using the TEOM to show instantaneous dynamic behavior of TSP emissions. The second objective is to measure nitrogen inputs to the facilities for which ammonia (gas) losses are being accurately monitored. Monthly feed, manure, and water samples will be taken along with an estimation of the animal feed used and manure produced.Samples will be sent to a local testing laboratory and analyzed for nitrogen (total Kjeldahl N, and ammoniacal N). This information will be used for a nitrogen mass balance in the buildings as a method of estimating the potential of the system to produce ammonia. The ammonia emission from the building will be expressed as a percentage of input.
  • Ammonia Emission Factor for Dairies – Dr. Mukhtar, Cale Boriack and Adam Rose

   Preliminary Ammonia emission factors were reported by Mukhtar et al (2003) of 30 lbs/1000hd/d. This emission factor is approximately 50% of the factor that has been used by some State Air Pollution Regulatory Agencies (SAPRA). This study is unique in that it is based upon flux measurements from a number of different sources (free stall, open lot, lagoon, composting, etc.) and an emission factor based on a “weighted average” of the area sources. We are continuing to gather data to confirm our preliminary emission factor.

  • Protocol for Determining Emission Factors of Ammonia and Hydrogen Sulfide using Isolation Flux Chambers – Drs. Mukhtar, Parnell and CREW

   One of the most important objectives for this research was to establish the appropriate protocols for flux determinations and ultimately emission factors. There is some disagreement in the literature on how one should properly perform the measurements and calculate fluxes. We took the conservative approach (EPA protocol). We purged the chamber for 30 minutes, measured concentrations for 30 minutes, and moved the chamber to another location. Some researchers are suggesting that losses due to adsorption of gas molecules to the exposed chamber surface and transport tubing are equivalent to the measured concentration. (If this were true it would in effect double the flux.) Rose reported that the losses occurring in the Teflon and LDPE tubing were statistically insignificant. We will be performing additional controlled tests to confirm Rose’s findings.

  • HRVOC Field Measurements from Concentrated Animal Feeding Operations (CAFOs)

   Work was initiated to characterize the level of highly reactive organic compounds (HRVOC’s) found in representative beef cattle feedyard and dairies in Texas. The goal of the study is to develop a protocol to identify and quantify the HRVOC’s emitted from concentrated animal feeding operations (CAFOs) that would cause the increase in the level of ozone in the atmosphere, ozone being a regulated compound. No standard protocol exists to measure HRVOC in the field.