Ammonia Emission Control for Liquid Manure Storage Practices - Acidification

Depending on the pH, N can exist in different forms . Reducing the pH maintains more nitrogen in the form of ammonium, which is not released as a gas. Therefore, strategies that acidify manure (reducing the pH) can be used to trap ammonium and prevent its release as ammonia. Among these strategies are dietary practices used to acidify urine by including phosphoric acid. However, ammonia emissions are more related to the buffering capacity or alkalinity, of the manure than to pH, suggesting that pH of excretions may increase during the storage, therefore reducing the effectiveness of this strategy. A disadvantage of acidification is that although it traps ammonia, the reduced pH is conducive to volatilization of hydrogen sulfide, another odorous compound produced from the anaerobic decomposition of manure. Costs associated with this practice include the acid and the equipment to apply and mix the acid with the stored manure.

Extension Publications

• PM 1971a Practices to Reduce Ammonia Emissions from Livestock Operations (pdf)
• PM 1971b Practices to Reduce Ammonia Emissions from Livestock Operations Flowchart (pdf)
• PM 1990 Instruments for Measuring Concentrations and Emissions Rates of Gasses and Particulates From Animal Feeding Operations (pdf)
• EDC 162h Air Quality and Animal Agriculture (pdf)
• PM 1936 Air Quality Resources for Iowa Animal Agriculture (pdf)
• PM 1935 Gaseous Emissions from Animal Agriculture (pdf)

Abstracts, Conference Proceedings, Presentations and Reports

• Management Impacts on Ammonia Volatilization from Swine Manure (pdf)
• Reducing Ammonia Emissions by Combining Covering and Acidifying Liquid Manure

Journal Articles

Newsletter Articles

• EPA releases the Animal Feeding Operations Air Quality Compliance Agreement

Other Links

• Section 3 Outdoor Air Quality (MWPS-18)