Wet air scrubbers are used on ventilation air as it exits livestock housing. Some wet scrubbers use water, which is then partially recirculated, while others use an acid or base to shift the pH for absorption of specific gases in the air. The current technology behind chemical and biological wet air scrubbing at livestock facilities can be optimized by careful maintenance and recalibration. European and regional air quality policy in the last decades has increased pressure on pig and poultry farmers to limit their farms’ emissions. The emissions from animal houses consist of feather and hair fragments, skin debris, feed particles, mold spores, bacteria, fungus fragments, litter fragments, etc. The size of particulates varies between 0.005 and 100 μm in diameter. The fine particulate matter has a negative effect on the human respiratory system and cardiovascular system. Emission of airborne particles and aerosols might be a relevant means of transmission for the spread of infectious diseases among farms and toward people. Moreover, emissions from livestock facilities often contain ammonia.
Wet air scrubbers are widely used to remove ammonia and odor in order to comply with government regulations. More than 95% of the air scrubbers used in European countries at livestock facilities are applied at pig houses, and less than 5% is used in poultry houses, where the application is complicated by wet air scrubber clogging. Clogging occurs due to a relatively high total dust content of the exhaust air, which causes blockage of the packing material, which often happens in packed bed scrubbers. Clogging is a problem for most wet air scrubbers, including packed bed scrubbers, venturi wet air scrubbers, and cyclonic wet air scrubbers.
Nowadays continuous measuring systems, that records data during an entire-fattening period, are increasingly being used to determine the amount of ammonia removed. The variations in day vs. night, size of the animals, animal behavior, barn management, and other factors can be related to the air scrubbing data. To measure the ammonia reduction even more precisely, the outgoing air must, therefore, be measured in several places.
A series of recent studies show that chemical wet air scrubbers are now capable of capturing up to 95% of ammonia from the air. The biological wet air scrubbers achieve a maximum rate of 80-85%.
Being a new type of wet air scrubber, multi-vortex wet air scrubber provides improved air treatment quality and can be used for both particles matter and gas collection. The treatment quality of multi-vortex wet air scrubber is generally 99.95-99.99% for both types of pollutants. Besides high efficiency, multi-vortex wet air scrubber possesses a number of advantages over conventional wet scrubbers – multi-vortex wet air scrubber is compact, omnivorous, eco-friendly, economical, and low-maintenance.