| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a circulation type flush toilet system which can recover the activity of a microorganism by rapidly adding organic matter, even if the activity of the microorganism is decreased owing to lack of the organic matter in sludge. <P>SOLUTION: In this circulation type flush toilet system 1, the organic matter of sewage, included in sewage from a water closet 5, is decomposed in a biological treatment tank 6, and subjected to nitrification and denitrification treatment. Biologically treated water, which is biologically treated in the tank 6, is subjected to solid-liquid separation in a filtration tank 7, and filtrate water is subjected to oxidation/decoloring treatment by ozone in an ozon decoloring tank 8. Treated water subjected to the oxidation treatment is returned to the water closet 5 so as to be reused as washing water. A case 35, wherein a biodegradable plastic plate is housed, is fixed to the tank 6, so as to supply the organic matter lacked by a denitrifier. A controller 11 makes a pump 12 operate according to a measured value of a pH sensor 27 which is provided in the filtration tank 7, so that easily decomposable organic matter can be added into a denitrification tank 6a. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
