| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1711713 | Biosystems Engineering | 2011 | 12 Pages |
In coming years large livestock farms will have to significantly reduce their emissions of odours, ammonia and dust to the surrounding area. The characteristics of a prototype air cleaning system for emission control in livestock buildings were measured using a pig rearing building. The system uses a two-step process: (1) absorption and (2) nitrification. The absorption process takes place in a scrubber, in which ammonia is removed by a water spray. The nitrification process takes place in water purification unit, in which the ammonia in water is oxidized to nitrites and nitrates using a microbiological process. Scrubbers or spray towers can be installed in ventilation stacks. Water purification unit is a central unit, which recycles water with a controlled pH to the spray towers. In tests, the water purification unit was able to maintain the spray water at pH < 7.5, which enabled 55–95% ammonia removal efficiency. Further development of the system is required to reduce the consumption of water and optimise the microbiological processes in the water purification unit.
► A prototype of two-step air cleaning system using recycle water has been developed. ► It consists of a spray tower and a microbiological water purification unit (BWPU). ► Step 1: The spray tower removes ammonia in discharge air from a pig rearing building. ► Step 2: BWPU nitrifies ammonia and returns the water to the spray tower. ► Water pH remained <7.5, which enabled 55–95% ammonia removal efficiency.
