| 摘要 |
PROBLEM TO BE SOLVED: To provide a methane fermentation system and a methane fermentation method which can properly adjust the pH of organic wastewater during a period of stopping the introduction of the organic wastewater from the outside, and can suppress hydrogen sulfide inhibition.SOLUTION: A methane fermentation system 1 includes: an acid production tank 2 which treats organic wastewater introduced from the outside by acid producing bacteria to produce acid; pH adjusting means 5, 6, 7 which adjusts the pH of the organic wastewater; a methane fermentation tank 3 which performs the methane fermentation of the organic wastewater introduced from the acid production tank 2; and a return line L2 which returns a part of treated water in the methane fermentation tank 3 to the acid production tank 2, wherein the pH adjusting means 5, 6, 7 includes compound adding means 7 which adds a compound for neutralizing alkali in the acid production tank 2 and reacting with hydrogen sulfide generated in the methane fermentation tank 3 to generate sulfide precipitation during a period of stopping the introduction of the organic wastewater from the outside. |
