REDUCTION OF ODOR AND VOLATILE SUBSTANCES IN PIG SLURRIES BY USING PIT ADDITIVES

The effects of five commercial pit additive products on the release of odor nuisance and volatile compounds from swine manure were examined in this study. The changes of pH, volatile fatty acids, total solids, total volatile solids, total nitrogen, and total ammonia nitrogen in s wine manure were measured and the levels of aerial ammonia and hydroge n sulfide were monitored. The odor threshold was determined by a dynam ic triangle forced-choice olfactometer. The results showed that all th e five products reduced the levels of odor threshold by different degr ees ranging from 58% to 87% as compared with the control samples. Thre e of the five products showed reductions in volatile fatty acids and t otal volatile solids. Comparing the reduction in odor threshold levels with the changes in the amount of volatile fatty acids indicated that the malodor intensities are not proportionally related to the overall amount of volatile fatty acids existing in the swine manure. The malo dor could be produced by certain types of volatile fatty acids which a re not necessarily present in high concentrations. The abatement of am monia emission from swine manure were not determined in this study due to low pH values for both the treated and the control samples.