| 摘要 |
PURPOSE: To improve the membrane filtering efficiency of a separation membrane while performing membrane separation treatment without stopping the operation of a membrane separator when the biologically treated water from an aerobic biological membrane treatment apparatus is treated with the membrane separator while achieving the keeping of the high flux of the membrane separator, the reduction of chemical washing frequency, the enhancement of water treatment efficiency and the stable operation of a water treatment system. CONSTITUTION: Aq. hydrogen peroxide is added to the water biologically treated in an aerobic biological membrane treatment apparatus 20 from an aq. hydrogen peroxide injection unit 26 and the concn. of hydrogen peroxide in the biologically treated water is set to 1-100mg/l. Subsequently, the biologically treated water is introduced into a membrane separator 34. Or, at the time of the backwashing of the membrane separator 34, aq. hydrogen peroxide is added to backwashing water so that the concn. of hydrogen peroxide is set to 1-100mg/l. |
