2009 Annual Report
1a.Objectives (from AD-416)
There are four main objectives for this study:
1) Develop PM2.5 emission factors and verify current PM10 emission factors for cotton gins across the Cotton Belt through stack sampling at gins in the West, Texas, MidSouth, and Southeast.
2) Collect field data to further quantify PM10 and PM2.5 EPA federal reference method stack and ambient sampler errors.
3) Develop point source and ambient total suspended particulate (TSP), PM10, and PM2.5 data sets that can be used in the design, development, and evaluation of current and future air quality models used for low-level agricultural sources.
4) Characterize the particulate matter emitted from cotton gins across the Cotton Belt in terms of particle size distribution, particle density, and particle shape.
1b.Approach (from AD-416)
The project plan is to evaluate six sites over the 2008 to 2010 ginning seasons, including a New Mexico gin, two California gins, a Texas gin, a Missouri gin, and a North Carolina gin. Selected gins should have similar abatement technologies (1D-3D cyclones with 2D-2D inlets on all exhausts) and process streams similar to the following: Module feeder or suction, No. 1 pre-cleaning, No. 2 pre-cleaning, overflow, No.1 lint cleaning, No. 2 lint cleaning, mote fan, mote trash fan, battery condenser, and master trash. Stack sampling will adhere to EPA protocols and will be performed by a certified stack sampling company under the supervision of the investigators. Stack sampling methods will include CTM-039, the EPA method for measuring PM2.5 stack emissions; Method 201, a standard EPA method for measuring PM10 stack emissions; and Method 5, a standard EPA method for measuring TSP stack emissions. Ambient air sampling will coincide with the stack sampling and will be conducted by USDA-ARS personnel and collaborators. The ambient sampling will follow USDA-ARS Air Quality Laboratory protocol. Samples of gin trash and other potential sources of ambient particulates (i.e., gin yard material) will be collected for analysis as particulate emissions parent material. Laboratory analyses, gravimetric and particle size analysis, and particle shape analysis will be conducted. All raw data will be compiled and organized for outside review. Results will be compiled in a report to the cotton ginners associations and project cooperators. The research will also be documented in the form of a series of manuscripts in peer reviewed technical journals to further disseminate the information for wider acceptance by the regulatory agencies and the scientific community.
The first sampling campaign in Vado, NM, at Mesa Farmers Gin was completed on December 22, 2008, and progressed as expected. Twelve process streams were sampled and 10 complete days of ambient samples were collected. There were delays starting the project due to equipment issues, but this was expected and was the primary reason for selecting a gin close to the USDA-ARS Southwestern Cotton Ginning Research Laboratory in Mesilla Park, NM. All samples and data sets for the Mesa Farmers campaign reside at the USDA-ARS Air Quality Laboratory in Lubbock, TX. Gravimetric processing of the stack sampling filters and washes for the Mesa samples was completed. Approximately one-third of the ambient sample gravimetric analyses were completed. A Beckman LS230 laser diffraction analyzer, on loan from another ARS unit, was repaired, calibrated, and installed at the Air Quality Laboratory to enhance the Lab's current Coulter Counter particle size analysis capabilities. Processing of the samples for particle size distributions as they exit the gravimetric analysis queue has begun. Currently, there is no estimated time of completion for the particle size analysis, as sampling at the gins for 2009 will begin in August and run through the fall. Although processing the 2008 samples was high priority, the primary focus has been to prepare for the 2009 sampling campaigns. Plans include a sampling campaign at a South Texas gin and two California gins. Preliminary site evaluation, test system selection, and sampler array placement was conducted by the PIs in June at the California and Texas gins. The sampling campaign at the South Texas gin will run August 10-25. The California gins, saw and roller, are located on the same property and will be sampled back to back with sampling beginning around 15 October and running for about 26 days. As typical with ginning operations, these dates and timeframes are subject to changes in the cotton crop and weather. For the 2009 sampling campaigns, sample media preparation (8500 filters and 2200 tubs) is complete, equipment repairs (e.g., truck, samplers, generators, pumps) are approximately 95% complete, sampler flow verification analyses are about 95% complete, sampler software modification and reinstallation are about 30% complete, and logistical plans for specific sites, including fabrication and installation of extensions and installation of electrical lines, are 99% complete for South Texas and 60% complete for California. The investigators are currently working on a manuscript detailing the sampling plan for the project, and presentations on the sampling plan were made at the 2009 Beltwide Cotton Conferences in San Antonio, TX and at the Green Acres, Blue Skies II Conference in Davis, CA.