Abstract
In order to recover and utilize the ammonia, which is a bi-product in the process of composting, we developed a novel composting system using vacuum-type aeration. In this system, it is possible to recover ammonia via ducts arranged at the bottom of raw materials during the vacuum aeration. The ammonia recovered in this system are reacted with phosphoric or sulfuric acid in ammonia-recover equipment and can be utilized as nitrogen fertilizers. When these fertilizers were used for cultivation of melons and paddy rice, it was demonstrated that the effects of these fertilizers were equal to chemical fertilizers.
