| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for applying methane fermentation sludge through utilizing it as a liquid fertilizer for hydroponics, and to provide a substrate for cultivation. <P>SOLUTION: The method comprises the following process. Each specified amount of methane fermentation sludge produced from the methane fermentation step in a methane fermentation unit 1, a membrane separation liquid obtained by membrane separation of the methane fermentation sludge by a membrane separation unit 3, and a dehydration filtrate obtained by dehydrating the methane fermentation sludge by a dehydrating unit 4 are introduced into a component adjustment tank 2, where the mixing proportion of each of the liquid fertilizer materials is adjusted to prepare a liquid fertilizer, oxygen is taken in the liquid fertilizer by exposing it to air, the resulting liquid fertilizer fortified with oxygen is fed to the substrate 7 for cultivation as a hydroponic medium, concurrently oxygen in air is taken in the substrate 7 to convert the ammonia-nitrogen in the liquid fertilizer into nitrate-nitrogen with the help of the nitrifying action of nitrifying bacteria held in the substrate 7, and the resultant liquid fertilizer is fed to a plant for cultivation in the substrate 7. <P>COPYRIGHT: (C)2004,JPO |
