WATER PURIFYING APPARATUS

摘要

PURPOSE: To provide a water filtering system removing both of org. suspended matter and dissolved phosphorus in water of lakes and marshes or the like. CONSTITUTION: Water to be treated taken in by an intake pump 4 is introduced into the lower part of a filter tank 1 packed with a granular cristobalite/ limestone mixed filter material 2. The water intoruded into the filter tank 1 is distributed by a gravel bed 3 to upwardly flow through the granular cristobalite/limestone mixed filter material 2 above the gravel bed 3. At this time, the granular cristobalite/limestone mixed filter material 2 is brought to a fluidized state. Purified water overflows from the upper part of the filter tank 1 as filtered water to flow out to a sedimentation tank 5. The filtered water (supernatant water) of the sedimentation tank 5 is discharged by a purified water drain pump 6 while the precipitate accumulated on the bottom part of the sedimentation tank 5 is withdrawn by a sludge withdrawing pump 7. A part of water to be treated is introduced into a high pressure tank 8 while raised to about 7 atm in pressure by a high pressure water pump 9 and air raised in pressure by a compressor 10 is introduced into the high pressure water in the high pressure tank 8 to be dissolved therein. This high pressure water is discharged to the lower part of the filter tank 1.