| 摘要 |
<p>PURPOSE:To ensure that the amount of alkali used for pH value adjustment is reduced in an acid production process by aerating a liquid in the acid production process to remove carbonate, in a method for anaerobic treatment of an organic waste water by which to return part of a treated water flowing out of a methane production process to the acid production process. CONSTITUTION:Untreated water 4 is conducted into an acid production tank 1 using a pump 5 to mix it with acid-producing bacteria in the tank. Next, the liquid 6 in the tank is stirred by circulation using a pump 7 to perform the acid production process based on an aerobic treatment. In this case, the treated water 8 is returned from a treated water tank 3 using a pump 9 and is aerated by sending air to an air injection device 11 from a blower 10. Further, alkali 13 is added to adjust the pH value so that the pH system 12 maintains a specified pH value. This alkali for pH value adjustment is consumed for the neutralization of carbonate dissolved in the liquid, in addition to the neutralization of an organic acid generated through acid production reaction. Therefore, the amount of alkali used for pH value adjustment can be reduced by removing the carbonate by aeration.</p> |
