Dairies face restrictive air and water quality regulations for manure, and compliance represents a significant cost. To remain competitive, dairies need manure management systems that are Economically viable, Environmentally responsible, and Produce value-added products. Each US dairy cow generates 25,000 lbs/yr of manure. The innovative technology developed in this initiative will reduce capital and operating costs of manure composting systems. OBJECTIVES: 1. What are the determining thresholds within the composting process that optimize for the lowest capital costs and operational power inputs, producing the least environmental impacts and highest quality bedding? 2. What is the optimal balance among pathogen control, carbon loss, power consumption and bedding quality? Lowest possible carbon loss; the composting process volatilizes carbon, and potentially ammonia. The further a feedstock is composted, the more carbon is volatized into the atmosphere. If less mature compost is suitable for use as bedding, less material will be volatized, resulting in more product and less air quality impacts. The optimal process, in terms of air quality, will be the shortest process that creates the most immature compost. Power consumption; composting uses energy to aerate piles. This energy use has indirect environmental and is expensive. The optimal process in terms of energy will be one that uses the least amount of energy, most likely the one with the least composting. Bedding quality; the more thoroughly composted the manure, the more broken structurally it is and smaller its particle size. Optimal bedding has more structure to it, not less, and the less composting the better. APPROACH: 1. ECS Develop Aeration Floor Designs ECS engineering staff will develop air-flow and structural models as the basis for a floor specification. The concepts will then be evaluated for material suitability, operational efficiency, and manufacturing cost. Floor designs will be selected to be purchased, assembled and tested at the WSU composting trials. 2. ECS Develop Pile Cover Designs ECS will obtain samples of likely materials and get quotations for assembling covers with tie-downs, temperature probe ports, and air-intake orifices. Semi-permeable fabrics will also be investigated as means of eliminating the air-intake ports and further reducing cost. Calculation of flow rates versus pressure differentials will be conducted to determine the desired porosity. 3. ECS Implement Upgraded Control System at WSU ECS will travel to WSU to install, calibrate, and start-up the upgraded control and data-logging features. 4. ECS Supervise Aeration Floor and Pile Cover Tests at WSU ECS will travel to WSU to supervise the start-up of the aeration floor and pile cover tests. With the results of these tests, ECS and WSU will select the aeration floor and pile cover designs to be used in the remaining compost trials. 5. WSU Compost Trials Each trial will take approximately one month, including set up, tear down and clean up. Each trial will consist of building and operating four piles (40ft x 20ft x 9ft tall) in four separate zones. The second set of three trials will narrow down the highest optimal range of temperatures within increments of 5 degrees F. Other process data that will be monitored and logged during these trials will include: Oxygen levels will be checked daily using a hand-held oxygen meter. 6. WSU Monitoring Air Emissions Samples will be taken from the exhaust gas output from each zone, as well as from the biofilter surface. All monitoring will be conducted for all zones. WSU will monitor VOCs, methane and ammonia emissions from each zone for all trials. 7. WSU Pathogen Kill and Re-growth Tests Tests will be conducted to determine the level of pathogen reduction and susceptibility of pathogen re-growth of composted bedding. 8. WSU Compost Characteristic Testing WSU will conduct laboratory analysis of biomass samples to determine C:N ratios, bulk density and will track volume changes in biomass during composting. 9. WSU will analyze Lab data and develop a report 10. ECS Develop Thermodynamic Model For Biofilter Efficiency ECS will use test data as the basis of a thermodynamic model to correlate to make-up air, re-humidification, and biofiltration equipment sizing to theoretical biofilter efficiency. 11. ECS Develop Economic Model ECS will develop a pro-forma economic model to estimate the life-cycle cost of employing low aeration covered ASP composting as manure management methodology. 12. ECS Phase I Final Report ECS will assemble the data from the Phase I testing and analysis into a final report
