Permeable Covers for Odor and Emissions Control from Swine Manure Lagoons

Permeable fabric covers have the potential to provide odor and emission control for manure lagoons without the expense and operational problems associated with impermeable covers. This paper describes a long-term controlled test of the odor control effectiveness of permeable covers at Premium Standard Farms (PSF) in northern Missouri. Many odor control evaluations at swine farms have suffered from short experimental time frames and lack of controls to verify the performance of the odor control technology. Controls are necessary because the odor and emission properties of manure lagoons change over the course of a year. In the absence of a control, normal changes in lagoon properties may appear to be the result of a treatment. Other evaluations have been laboratory scale evaluations that may not be indicative of the fullscale performance of a technology. The permeable cover evaluation at PSF was designed so that these problems would be avoided. Ambient odor and hydrogen sulfide measurements have been taken at a covered lagoon and at a control lagoon twice monthly for two years. Samples of liquid lagoon effluent have been taken monthly and analyzed for TKN, ammonia, sulfide, phenols, and volatile fatty acids (VFA). Ambient air quality was significantly better at the covered lagoon in terms of both odor and hydrogen sulfide. Results from liquid sampling show that there may be some buildup of odorous compounds in the liquid fraction of the covered lagoons. Future plans include odor sampling to determine if the increase in odorous compounds in the liquid phase results in increased odor in production buildings where recycled lagoon water is used to flush manure alleys. In addition, long-term source monitoring will be conducted to determine the overall abatement efficiency of the covers for emissions of hydrogen sulfide and ammonia.