OLIGOLYSIS - EFFECT OF VOLTAGE ON ODOR AND SULFIDE REMOVAL IN STORED PIG MANURE

Oligolysis appears to effectively reduce odours by removing sulphur co ntaining compounds from stored liquid manure. The objective of this ex periment was to test the effect of voltage level on the effectiveness of this process in reducing these compounds. The experiment consisted of six treatments, 1.5, 2.0, 2.5, 3.0, and 3.5 volts and a control (no voltage). Liquid samples were obtained at o, 0.5, 3, 24, and 168 h fr om 0.225 m(3) bioreactors and the gas samples were obtained at 0, 24, and 168 h. The liquid samples were analyzed for free and total sulphid es while the gas samples were analyzed for hydrogen sulphide (H2S). Li quid samples taken at 168 h were tested by eight odour panelists to de termine a threshold odour number(T.O.N.). The results indicate that al l voltage treatments removed over 97% of the free sulphides in liquid pig manure. The mean concentration of H2S in the gas released from the treated bioreactors was 91% less than the control. No significant dif ferences in sulphide levels were observed at the applied voltages.