CONTROLLING ODOR AND VOLATILE SUBSTANCES IN LIQUID HOG MANURE BY AMENDMENT

Five commercial pit additive products were examined for effectiveness of controlling the release of odorous and volatile compounds from swin e manure. pH, volatile fatty acids, total solids, total volatile solid s, total N, and total ammonia N were monitored, and levels of aerial a mmonia and hydrogen sulfide were measured. Odor thresholds were determ ined by a dynamic triangle forced-choice olfactometer. The five produc ts tested reduced the odor thresholds from 58 to 87% as compared with control samples. Three of the five products showed significant reducti ons in volatile fatty acids (34-44%; P < 0.05). Correlation analysis s howed that the odor threshold is not correlated with volatile fatty ac ids concentrations existing in the swine manure (coefficient of correl ation: r = 0.16). Malodor could be produced by certain types of volati le fatty acids not necessarily present in high concentrations. The aba tement of ammonia emission from swine manure was not determined in thi s study due to low pH values for both the treated and control samples.