| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain irrigation water usable as city water as well by introducing collected rain water to a refining section installed under the ground and passing the water through biological treatment filter media, thereby biochemically removing impurity org. matter. SOLUTION: The rain water collected to a trough body 4 is introduced to the upper part of an inside cylindrical body 2, on the inner side of which is freely attachably and detachably provided with plural pieces of cage bodies 6. These cage bodies may be freely taken into and out of the cylindrical body through an opening 7. The biological treatment filter media 8 are housed in the cage bodies 6 to refine the rain water flowing therein. The biological treatment filter media 8 are the filter media formed by depositing microorganisms which proliferate with the impurities included in the raw water as nutrient components on hollow or spherical plastic bodies or ceramic bodies of about 1 to 5 mm in diameter to remove the org. matter in the rain water with which these media come into contact. The rain water refined by passing the inside cylindrical body 2 enters an outer cylindrical body 3 from a drain port 9 in the lower part and is introduced to a water treating device 12 through a pipe 11 by a submersible pump 10 installed in the lower part of the outside cylindrical body.</p> |
