| 摘要 |
PURPOSE:To compact an equipment by treating drainage containing pollutive organic substance by a biologically treating device with a nonwoven fabric carrier used therefor and passing the treated water through a membrane separa tor with an internal pressure type hollow fiber membrane module used therefor. CONSTITUTION:Since the water treated by biologically treatments 4-1, 4-2 with a nonwoven fabric carrier used therefor is small in blocking properties of a membrane module, it is enabled that membrane separation is performed by using an internal pressure type hollow fiber membrane module 6 in a rear stage. Thereby the thickening properties of sludge are more enhanced. In other words, when the biologically treated water is passed through the internal pressure type hollow fiber membrane module 6, sludge is compacted and thickened in the inside of hollow yarn. In the case of backwashing the hollow fiber membrane, the accumulated sludge is not dispersed in backwashed drainage but is made tubificidlike and discharged. Since the tubificidlike sludge is already thickened at some degrees and excellent in settling properties, it is made compact by enlarging the upward flow velocity in a sludge thickener 7. |
