EFFECT OF OZONATION ON ODOR AND THE CONCENTRATION OF ODOROUS ORGANIC COMPOUNDS IN AIR IN A SWINE HOUSING FACILITY

Abstract

This study reports the effect of ozone on odor thresholds and the concentration of selected odorous organic compounds in a swine housing facility. This study was conducted in four rooms that each housed 24 pigs. Ozone was injected at different rates into the each of the rooms to give a final concentration of gaseous ozone in the rooms of approximately 0 (control), 0.01, 0.05, or 0.1 ppm. The concentrations of phenolic and indolic compounds and volatile fatty acids (VFAs) were measured in the air in the rooms using solid-phase microextraction (SPME). The results showed that ozonation reduced the levels of indolic compounds in the swine building air significantly (at the 95% confidence level). However, the reduction in the levels of volatile fatty acids and phenolic compounds in the air was small and generally not statistically significant. Sensory measurements showed that there was a small increase (less than 0.5 log units) in the odor detection thresholds for air in the ozonated rooms. At the ozone levels used in this experiment, the reduction in odor levels achieved is small. It is not likely to be practicable to achieve significantly higher reductions in odor levels, as the ozone concentration needed would exceed the OSHA permissible exposure limit for ozone.