<；P>；PROBLEM TO BE SOLVED: To provide a water cleaning apparatus and method for cleaning water, which can attain a satisfactory effect even when water is highly eutrophic. <；P>；SOLUTION: Raw water to be cleaned is pumped out and is introduced into a micronanobubble generating tank 2 in which micronanobbuble generating units 6, 7 are installed. In the micronanobubble generating tank 2, micronanobubbles are generated. Aerobic microorganisms in the treatment water are activated by the micronanobubbles to decompose algae in the treatment water into nitrate nitrogen. The micronanobubble-containing treatment water is introduced into a plant cultivation tank 3 comprising a fixed planting bed 14, in which a water plant 13 has been fix planted, and disposed under water, whereby nitrate nitrogen is absorbed as a nutrient in the water plant 13. <；P>；COPYRIGHT: (C)2008,JPO&INPIT
