| 摘要 |
PURPOSE:To obtain clarified water which does not contain harmful organic substance, by subjecting crude water for city water to neutralization, coagulation, prechlorination and filtration, supersonically aerating the pretreated water, and then disinfecting the aerated water. CONSTITUTION:At first, crude water for city water is subjected to ordinary neutralization, coagulation, prechlorination and filtration. The pretreated water is then subjected to ultrasonic aeration using ultrasonic waves having an osicllation frequency of 10kHz or more. Said supersonic aeration means treatment with supersonic waves generated when bubbles are broken or treatment with ultrasonic waves while generating bubbles. After the supersonic aeration, the clarified water is treated with a chlorinating agent such as sodium hypochlorite. According to this method, clarified water which does not contain harmful organic substance such as methane trihalide can be obtained under the condition that the residual chlorine content is held at 0.1ppm or more regulated under the City Water Law. |
