| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and apparatus for treating organic material-containing waste water, which, in treating high-concentration or low-concentration organic material-containing waste water discharged from electronic device manufacturing plants and other various fields in an RO membrane separating apparatus to recover water, prevents a lowering in flux and biofouling caused by deposition of organic materials onto the membrane surface within the RO membrane separating apparatus to conduct stable treatment over a long period of time and, at the same time, to efficiently lower the concentration of TOC in water for providing high-quality treated water. SOLUTION: A scale inhibitor in an amount of not less than 5 times by weight larger than the concentration of calcium ions in water is added to organic material-containing waste water. In addition, the waste water is adjusted to pH 9.5 or higher by the addition of an alkali and is then passed through an RO membrane separating apparatus 2. Bringing the pH value of RO feed water to 9.5 or higher can prevent biofouling in the RO membrane separating apparatus, can prevent the deposition of a nonionic surfactant onto the membrane surface to prevent a lowering in flux. The addition of the scale inhibitor can inhibit clogging of the membrane surface by calcium carbonate scale under high pH conditions. COPYRIGHT: (C)2005,JPO&NCIPI
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