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Test/QA Plan For Verification Of Anaerobic Digester For Energy Production And Pollution Prevention
Citation:
Wagner, D., W. J. DAVIS-HOOVER, AND J. R. HAINES. Test/QA Plan For Verification Of Anaerobic Digester For Energy Production And Pollution Prevention. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-11/080, 2011.
Impact/Purpose:
To verify digester performance in the areas of pathogen reduction, waste stabilization and biogas production.
Description:
The ETV-ESTE Program conducts third-party verification testing of commercially available technologies that improve the environmental conditions in the U.S. A stakeholder committee of buyers and users of such technologies guided the development of this test on anaerobic digesters. Large scale animal agriculture in the United States produces manures in excess of one billion wet tons per year. This waste is commonly spread upon cropland both as a fertilizer and as a disposal mechanism. As a result of this activity, water quality and air quality are degraded throughout the nation. The three most common causes for listing waters as impaired are nutrients, sediments, and pathogens, all of which are heavily associated with manure land application at Concentrated Animal Feeding Operations (CAFOs). Development of commercial technologies that can treat the waste and recover value from it is highly desirable. Anaerobic digestion of livestock manures under controlled conditions to produce biogas (a mixture of methane and carbon dioxide) can provide livestock producers with the opportunity to increase net farm income, typically by using captured biogas to generate electricity for on-site use, or delivery to a local electric utility, or both. An added benefit of anaerobic digestion of livestock manures is that potentially negative impacets of these wastes on air and water quality are reduced. The steady development of biogas systems and an awareness of their merits has produced an increased level of interest by livestock producers in manure biogas production and broadened their use from mostly dairies to a variety of waste streams. Concurrently, a number of different system designs have emerged with claims about performance superiority as the number of system developers has increased. To facilitate comparison between systems and verify performance, a standard evaluation protocol has been developed. The study evaluated the performance of the digester for one year, starting after 5 HRTs (hydraulic retention times) are completed during the startup phase of the digester. The objective of the study is to verify digester performance in the areas of pathogen reduction, waste stabilization and biogas production.