| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To find a method for keeping a water quality in a place easily retaining water flow at a relatively shallow part or the like such as a harbor, and a portion easily accumulating an eutrophic component having mainly ammonium such as a fish-breeding place inexpensively, over a long period and stably. <P>SOLUTION: In the method for cleaning the water quality by covering at least a part of a water bottom with sand having an average particle size of 1 to 20 mm, bulk specific gravity of 0.8 g/ml or larger, a porous surface and zeolitization, though it is sunken in the water bottom, since a marine animal can freely move between the bed part of the sea and a water part through a sand layer, the eutrophic component such as an ammonium ion or the like is adsorbed because of having a cation exchange performance, and also eutrophic component decomposing bacteria having mainly ammonium can be carried on the surface, the decomposition of such a component is successively carried out, thus environment in water is not changed and the eutrophic component can continuously be decomposed successively. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
