Odor Control for Liquid Manure Storage Practices - Solids Separation

Solids separation by sedimentation, screening, filtration, or centrifugation allows for the removal of material that exceeds the screen-opening size. Often, in the case of ruminant manures, this is a fibrous material that resists decomposition during storage. By removing large-sized material, thereby decreasing the loading rate, the life of the storage area can be extended. Decomposition of remaining stored material may benefit from removal of the poorly digestible material. Reduced odor emissions (intensity and concentration of odorants) from storage facilities are the result of improved decomposition. A 50 percent reduction in odor threshold from swine housing air samples was observed when a filter net was installed under the floor slats and daily removal of the solids collected on the net was conducted. This reduction may have been due, in large part, to the daily removal of material. Odor evaluation, following separation of dairy manure, showed no difference between separated and unseparated manure. Mechanical solids separators require a capital investment of $15,000 to $100,000. Typically, separation efficiency is much greater for ruminant manure because its particles are less uniform in size. Gravity settling (sedimentation) necessitates less capital investment but its impacts on odor reduction are undocumented.

Extension Publications

• PM 1970a Practices to Reduce Odor from Livestock Operations (pdf)
• PM 1970b Practices to Reduce Odor From Livestock Operations Flowchart (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)
• PM 1963a The Science of Smell Part 1: Odor perception and Physiological Response (pdf)
• PM 1963b The Science of Smell Part 2: Odor Chemistry (pdf)
• PM 1963c The Science of Smell Part 3: Odor detection and measurement (pdf)
• PM 1963d The Science of Smell Part 4: Principles of Odor Control (pdf)
• PM 1964 Odor Control Methods Used by Iowa Pork Producers (pdf)
• PM 1754i Iowa Odor Control Demonstration Project Solids Separation (pdf)
• FS925-A Understanding Livestock Odors (pdf)
• Michigan State University Extension Manure Solids Separation (pdf)
• Alabama Cooperative Extension System ANR 1025, Advantages of Manure Solid-Liquid Separation (pdf)
• Texas Agricultural Extension Service E13, Solid Liquid Separation of Animal Manure and Wastewater (pdf)

Abstracts, Conference Proceedings, Presentations and Reports

• Odor Rating System Demonstration Project U of MN
• Treatment of Flushed Dairy Manure by Solid-Liquid Separation and Lagoon Aeration

Journal Articles

Newsletter Articles

• Nutrient Recovery Options

Other Links

• Section 3 Outdoor Air Quality (MWPS-18)
• Minimizing Odor Generation, LPES Curriculum Lesson 41 (pdf)
• U of MN Frequently Asked Questions about Solid-Liquid Separation