PURPOSE: To remove microbiologic slime sticking to a filter medium and to prevent the sticking efficiently, by washing the filter of a filtering device with a fluid which contains ozone.
CONSTITUTION: In a filtering device of a water treatment plant, where the water to be treated, after being separated into solid and liquid in a sedimentation tank 1, is passed through a filter 3 of a filtering tank 3 to catch and remove the fine floc remaining in a liquid, and the purified water is introduced to a purified water tank 6; the filter 3 is required to be washed because the fine floc, together with microbiologic slime, etc., are accumulated in the layer 3. At the time of washing the tank 2, a gas which contains highly concentrated ozone is supplied from an intermittently supplying device 9 of ozone to a gas- liquid mixing device 10 through an ozonized gas feeding pipe 11 by closing valves 7a, 7b and opening a valve 7e and driving a pump 8b, and the obtained washing liquid which contains ozone is supplied to the surface of the layer 3 from a surface-washing piping 4 to perform the washing. After that, the filtering tank 2 is used again after clean water is sent by a pump 8a to backwash the filter 3.
YOTSUMOTO HATSUO
NAKAYAMA SHIGEKI
| JPS50118371A | 1975-09-17 |