| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of recycled water which does not require a large quantity of ozone and can stably provide recycled water from waste water while reliably preventing clogging on membrane surface inexpensively. <P>SOLUTION: The manufacturing method of recycled water is provided in which ozone is added to the waste water as raw water in an ozone contact tower 2, thereafter, a flocculant is added in a flocculation tank 4 and membrane filtration is performed by using a separation membrane 5 to obtain recycled water. Just prior to a flocculation process, a remaining ozone concentration in the raw water is measured by an ozone concentration measuring instrument 7 and ozone is added while controlling an ozone addition quantity such that the ozone concentration falls into the range of 0.2 to 2.0 mgO<SB>3</SB>/L, thereby, the surface of fine solid matter included in the raw water is reformed so as to have an easily flocculating property, further, a flocculant is added to flocculate the waste water and membrane filtration is performed by using an ozone-resistant separation membrane 5. <P>COPYRIGHT: (C)2009,JPO&INPIT |
