Exhaust air treatment for poultry facilities - only a partial success to date

Two different test facilities were operated over a period of eight month to clean exhaust air from two chicken stables. The exhaust air was initially cleaned by a dry working dust filter and subsequently scubbed with an acidified washing solution. Volumetric flow, carbon dioxide, hydrogen sulfide as well as ammonia were measured quasi continuously. The particulate matter reduction was detected 45 times and the odour reduction three times over the measuring period. At filter load between 2300 and 2600 m3/(m2 . h) an overall ammonia mass reduction up to 88% was achieved, if the scrubbing was operated with a pH value below 5. The particulate matter reduction was 73% (particle size range 1.3 - 1.6 um) and 99% (particle size range >5.0 um), respectivly. In spite of a good ammonia and particulate matter reduction the calculated odour reduction was insufficient with 16 - 37%. The typical odour perception from a chicken house could also not be eliminated.