Fine Dust (PmIO) Removal by Air Scrubbers Treating Animal House Exhaust Air

摘要

Air scrubbers (mainly acid scrubbers and biotrickling filter) are commonly used for removal of ammonia and odor from ventilation air of animal houses in The Netherlands in order to comply with current regulations. Besides, air scrubbers remove a largepart of the coarse dust and will to some extent also remove fine dust (PMIO). In this paper the state-of-art of scrubber application at animal houses is reviewed with regard to ammonia and odor removal. Next, the results are presented of a measurement program where PMIO removal of farm-scale air scrubbers was monitored year round. It was found that scrubbers with at high air contact time (Empty Bed Residence Time (EBRT) > 7.5 s) can achieve high PMIO removal efficiencies (on average 68%). At low air contact times (EBRT < 7.5 s), however, efficiencies were much lower (on average 44%). This might be explained by the phenomenon that the diameter of dust particles increases when passing through the scrubber, resulting in higher removal efficiency at higher contact time. However, further theoretical and experimental research is necessary to understand the wide range of PMIO removal efficiencies that was find at low contact times.