DEVICE AND METHOD FOR BIOLOGICALLY TREATING ORGANIC WASTEWATER

摘要

Provided is a device for biologically treating organic wastewater wherein strainers can be easily washed. Organic wastewater is treated in a first biological treatment tank 41 to give a first biologically treated water in which dispersed bacteria are increased due to decomposition of organic matters by dispersed bacteria. In a second biological treatment tank 42, the dispersed bacteria are preyed by animalcules. The first biological treatment tank 41 and the second biological treatment tank 42 are provided with tower bodies 50 that are the same in shape and size and have a height of 6-11 m. Strainers 54 are placed in the individual biological treatment tanks 41 and 42. To the strainers 54, air for backwashing is supplied from pipes 73 and 68 respectively.