The objective of this report is to demonstrate the effectiveness of biofilters to reduce odour, hydrogen sulfide and ammonia emissions from livestock facilities and manure storages using low cost biofilters with different designs, media, operating conditions and management.
The performance of twelve biofilters with different residence times (approximately 4,7 and 13 s) was measured on a dairy, swine and poultry facility. Residence times are defined as the time the air is in contact with the biofilter media.
Odour and hydrogen sulfide reduction improved from 56% to 94% as residence times increased from 4 to 7 s for the dairy and swine. Percent reduction remained about 89% as residence time increased from 7 to 13 s on the dairy and swine. A 5 s residence time is recommended for designing biofilters on swine and dairy facilities to achieve more than 80% reduction in emissions. The biofilter on the poultry facility was installed without a dust filter and dust on the fans prevented accurate airflow measurement. Reductions were less than 40% on the poultry biofilter.