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Research r...Environmen...A Biotrickling Filter

A Biotrickling Filter for Removing Ammonia and Odour in Ventilation Air from a Unit with Growing-Finishing Pigs

The present study was carried out to investigate the ammonia and odour removal with a commercial biotrickling filter (SKOV A/S, Glyngøre, Denmark) in a unit with growing-finishing pigs.


The results demonstrated that the filter significantly reduced the ammonia concentration (ppm) in the outlet air (P<0.05). Even though, the ammonia concentration before the filter ranged between 8.1 and 9.0 ppm during the winter period and 4.1 and 5.9 ppm during the summer period, the ammonia concentration after the filter was in the range of 1.2 to 2.4 ppm during the entire study.

The filter significantly reduced the odour concentration (OUE/m3) in the outlet air (P<0.05). However, there were large variations in the odour removal efficiency, which ranged from an average of 54 % during the winter period and 28 % during the summer period.

A possible explanation for the reduced odour removal efficiency during the summer was the increased ventilation rate, which reduced the retention time of the outlet air in the filter.

It was observed that some areas on the filter were clogged up with dust and biofilm and this may also have impaired the odour removal. In conclusion, the filter was able to reduce the ammonia and odour concentrations in the outlet air from a unit with growing-finishing pigs. However, it is required to improve the odour removal efficiency and to find methods to increase the retention time and prevent the clogging with dust and biofilm.

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Thomas Ladegaard Jensen

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Michael Jørgen Hansen