Simulation of Ammonia Emissions from Scrape and Flushed Dairy Manure Post-Collection Storages

Abstract

Manure scraping and flushing are the two common manure handling systems in concentrated animal feeding operations (CAFOs) in the United States. Previous studies have reported on the impacts of these two manure handling systems on ammonia emissions within barns. There are no studies comparing the impacts of the two manure handling systems on ammonia emissions during post-collection storages in lagoons and other similar manure storages although these facilities are known to account for the largest portion of ammonia volatilization in CAFOs. A series of bench scale experiments were conducted for a period of 23 days in controlled laboratory conditions to quantify and compare ammonia losses from typical storages of simulated scraped manure, and simulated flushed manure. Ammonia emission fluxes estimates (with cumulative ammonia emissions in the parentheses) over a 23-day period were 2.25±0.08g/m2/day (2034±106.5 mg) from the simulated scraped manure storage, 2.04±0.04g/m2/day (1739.3±53.3 mg) from the simulated flushed manure storages with 411 cm2 exposed surface area each, and 4.62±0.13g/m2/day (1752±56.3 mg) from the simulated scraped manure with 183 cm2 exposed surface area, respectively. These results indicate that ammonia emission fluxes from scraped manure storage would be more than from flushed manure storage by at least two times if both manure post-storages had approximately the same exposed surface area to the volume ratio. However, results also revealed significantly higher cumulative ammonia emissions from simulated scraped manure storage with 411 cm2 than from both the simulated flushed manure storage with 411 cm2 and the simulated scraped manure storage with 183 cm2 exposed surface areas.