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United States Department of Agriculture

Agricultural Research Service


Location: Cotton Ginning Research

2011 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.

3.Progress Report

This project was a companion project with 6235-41000-008-33R, -35R, -43R, and -40T as part of a larger, four-year effort to quantify cotton gin particulate emissions. Work on this project in FY2011 by ARS researchers from Mesilla Park, NM; Stoneville, MS; and Lubbock, TX, and Oklahoma State University researchers from Stillwater, OK, occurred in three main areas: sampling, data and sample analyses, and planning and preparation. In October 2010, 10 unique process stream exhausts equipped with cyclones at a cotton gin in west Texas were each sampled using EPA methods for stack sampling total particulate, particulate less than 10 microns in diameter, and particulate less than 2.5 microns in diameter. The gin was also surrounded by an array of 124 ambient samplers to measure the concentration of particulate around the gin as impacted by the gin emissions. Ambient samplers were operated for a total of 10 days while the exhaust stack sampling was conducted. More than 1500 samples were collected at the west Texas gin for post-processing. Sample analyses conducted at the ARS Air Quality Laboratory focused on processing more than 3000 samples collected at the west Texas gin and a Missouri gin sampled at the end of FY2009. Samples were inspected, sorted, and photographed. Gravimetric and particle size distribution analyses of all the Missouri and west Texas samples were completed. Raw stack sampling data from four previously sampled gins were compiled, checked, and merged with the particle size information to create the final master files to be used in the final report. Potential cotton gins in North Carolina for the 2011 sampling campaign were reviewed through communications with gin facility management, aerial photo analyses, and on-site evaluations. The subject gin was identified, and all preparations for the final sampling campaign planned for September and October during the 2011 ginning season are on schedule. Though researchers have stressed the need to avoid disseminating preliminary data "piece-meal" before completing all the sampling and data analysis, they compiled preliminary PM2.5 information from four of the total seven gins to be sampled for California regulatory officials who recently indicated that they are under pressure to complete their PM2.5 feasibility assessment cotton gin permits. These data reflected the best estimates to date and will likely vary after data from the final three gins are incorporated. The researchers completed a manuscript documenting the sampling plan and methodology for the overall project and prepared a presentation and proceedings paper for a technical meeting, detailing the progress to date.

Last Modified: 4/21/2014
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