| 摘要 |
PURPOSE:To remove the urea in raw water at a high degree by constituting the pretreatment device of the above-mentioned apparatus having the pretreatment device for the raw water, primary pure water producing apparatus and secondary pure water producing apparatus as a device including a biological treatment means. CONSTITUTION:The pretreatment device of the ultra-pure water producing apparatus for producing the ultra-pure water from the raw water, such as city water and ground water, is constituted of an upward current type biological decomposition device 20. This biological decomposition device 20 has a biological decomposition tank 22 which executes a biological treatment by holding bacterium soma to the surfaces of active carbon 21 or carriers, such as anthracite, sand, zeolite, ion exchange regins or plastic molded goods, and fluidizing the raw water introduced from the lower part in upward current. The outflow of an aeration tank 23 is similarly fluidized as the upward current and an aerobic condition is given, by which the bacterium soma is activated and the concn. of the TOC(total org. carbon) content, such as urea, in the raw water is lowered. The raw water emitted from the biolodical decomposition tank 22 is admitted by a discharge pipe 23B into the aeration tank 23 and is sent to the ensuing stage. |
