INNOVATIVE ANIMAL MANURE TREATMENT TECHNOLOGIES FOR ENHANCED ENVIRONMENTAL QUALITY
Location: Coastal Plain Soil, Water and Plant Conservation Research
Title: Removal and recovery of ammonia from liquid swine manure and poultry litter using gas permeable membranes
Submitted to: Recycling of Agricultural Municipal and Industrial Residues
Publication Type: Proceedings
Publication Acceptance Date: September 13, 2010
Publication Date: September 13, 2010
Citation: Vanotti, M.B., Szogi, A.A., Rothrock Jr, M.J. 2010. Removal and recovery of ammonia from liquid swine manure and poultry litter using gas permeable membranes. In: Proceedings of the 14th Ramiran International Conference, September 12-15, 2010, Lisboa, Portugal. 4 p.
We investigated the use of gas-permeable membranes as components of new processes to capture and recover ammonia from liquid manures and other concentrated effluents as well as from the air in poultry houses. The basic process includes the passage of gaseous ammonia through a microporous hydrophobic membrane and capture and concentration with circulating diluted acid on the other side of the membrane and production of a concentrated ammonium salt. The membranes can be assembled in modules or manifolds and can be tubular or flat.
For liquid manure applications, the membrane manifolds are submerged in the liquid and the ammonia is removed from the liquid matrix in barn pits or storage tanks before it goes in the air. The concept was successfully tested using concentrated swine manure effluents (digested and un-digested liquid manure) containing 300 to 1500 mg/L NH4-N. After ten batches, the ammonia was recovered and concentrated in a clear solution containing 53,000 mg/L NH4-N. Soluble compounds such as soluble COD did not pass through.
For the removal of ammonia in air, the technology captured and recovered 96% of the ammonia lost from poultry litter. The recovery of ammonia could mimic the slow release during flock production or could be accelerated to a few days using hydrated lime amendments. The membrane manifolds can be placed close to the poultry litter surface (above or below), reducing the exposure of the birds to ammonia. Considering the ammonia is captured inside the houses, this technology help reduce ventilation and energy needs to lower ammonia levels in poultry houses.
The results obtained in this study show that the use of gas-permeable membrane technology could be an effective approach to recover ammonia from livestock wastewater and from the air in poultry litter and other livestock operations. The final products are (1) reduced environmental emissions from livestock facilities, (2) cleaner air inside the poultry and swine houses with benefits to bird/animal health, and (3) concentrated liquid nitrogen that can be re-used in agriculture as a valued fertilizer.