It was compared the reduction effect of contaminants and odor according to DO change and EM (effective microorganisms) addition in maturation process of piggery slurry. The maturation processes were divided into three cases as follows: R-1 was operated at 2.5 mg/ℓ of DO without the addition of EM, R-2 was operated at 7.5 mg/ℓ of DO without the addition of EM and R-3 was operated at 2.5 mg/ℓ of DO with the addition of EM. The addition of EM was more effective than the increase of DO for the reduction of CODcr, NH3-N and T-N in the maturation of piggery slurry. In addition, the reducing effect of odor intensity appeared high even in the short-term maturation period in case of adding EM and one could not even smell the stimulating odor of piggery slurry.

The changes of contaminants and odor corresponding to anaerobic maturation process of piggery slurry were investigated by applying the additives, such as different kinds of complex microorganism products and deodorants containing microorganism activating agents. The pHs during 20-day anaerobic maturation were operated stably without great change regardless of the additives, although they were rather lower in the case that the additives were contained than the case that they were not contained. The effects of removing CODcr, NH3-N, T-N, and T-S in case that the additives were not contained, were not so great during the 20-day operation and so it would be difficult to remove the organic materials and nitrogen ingredients simply with anaerobic maturation process. However, in case of anaerobic maturation process that the additives were contained, their average removal rates were improved with the values of 49%, 63.5%, 48.5%, and 30.7% for above each of items, even if the 20-day of short-term maturation period was applied. Especially, odor intensity with the additives was lowered continuously during the operation period and it had more than two times of lowering effect compared to that without those.