Evaluation of Mechanical Scraper System Finishing Barn for Solid-Liquid Separation

Abstract. Laboratory and field tests were conducted to evaluate efficacy and practicality of an alternative swine finishing barn design, making use of a mechanical scraper manure separator system. The objective of the experiment was to evaluate performance in manure management, considering factors including solid-liquid separation characteristics for nutrient management and air quality. This research also incorporated testing the level of pretreatment and filtration for the liquid manure to be repurposed, as well as potential economic and environmental impacts. Waterproof pressure loggers were used to monitor the level of separated liquid manure in a collection pit. Volume of the separated solid manure was also monitored, along with barn inventory and feed consumption. The daily liquid manure production ranged from 103 to 7737 gallons, and averaged 1188 gallons. The weekly solid manure production ranged from 711 to 2820 gallons, and averaged 1721 gallons. Important nutrient contents and pH values were analyzed for the monthly liquid and solid manure samples. Ammonia concentrations measured at the wall and pit fans were relatively low compared with a deep-pit barn, ranging from 0.2 to 6 ppm. Liquid manure was filtered through various membrane processes, including reverse osmosis using a bench-scale cross-flow membrane system. The preliminary filtration results indicate that the pH values change significantly through the filtration stages, and the reverse osmosis process was time and energy intensive. Additional sampling and tests are being conducted to better characterize the economic impact, manure separation and filtration efficacy, and practicality of the manure separator system.