| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a waste water purifying apparatus in which waste water of high BOD (biological oxygen demand) can be treated efficiently without raising the equipment cost and running cost remarkably. <P>SOLUTION: Each of aeration tanks 11, 13 for performing aeration and precipitation tanks 12, 14 for performing precipitation is formed to have a tower-like structure consisting of a lower-side water storage part 15 and an upper-side basin part 16. These tanks are communicated with one another by a plurality of tower parts 17. A rhizome part of a hygrophyte or emergent 24 arranged in each of the basin parts 16 is grown in each of the plurality of tower parts 17. Since the rhizome part of the hygrophyte or emergent 24 functions as a carrier of a biological membrane, the organic matter in waste water is contacted with the biological membrane and decomposed oxidatively and the BOD concentration is lowered efficiently. If necessary, basins 27 in each of which another hygrophyte or emergent 26 is planted are arranged in a cascaded form on the downstream side of the precipitation tank 14 so that waste water is purified secondarily by the biological membrane-like action and filtration action of the hygrophyte or emergent 26. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
