| 摘要 |
PURPOSE:To decrease the frequency of membrane washing by providing the circulation circuit which returns the separated concentrated liq. with a ultrafilter membrane to a circulation tank, the return circuit which returns some of the concentrated liq. to a reaction tank and the culture circuit which returns some of the concentrated liq. to the reaction tank after introducing to the culture tank and reactivating the microorganisms in the concentrated liq. CONSTITUTION:This device is provided with the reaction tank 1 where the microorganismic treatment of waste water is executed, the circulation tank 2 which is formed integrally or in another body and the ultrafilter membrane 3 which separates the suspension after reaction into a membrane-permeated water and the concentrated liq. by using a pressure as a driving force. The circulation circuit 4 which returns the separated concentrated liq. with the ultrafilter membrane 3 to the circulation tank 2, the return circuit 5 which returns some of the concentrated liq. to the reaction tank 1 through or not through the circulation circuit 4 and the culture circuit 7 which returns some of the concentrated liq. separated with the ultrafilter membrane 3 to the reaction tank 1 after introducing to the culture tank 6 and reactivating the microorganisms in the concentrated liq. are also provided. In such a manner, the frequency of membrane washing is decreased and the lifetime of the membrane is prolonged. |
