PURPOSE:To increase treating capacity and to simplify back washing by packing an adequate amt. of small piece contact filter media made of a synthetic resin having the specific gravity equal to the specific gravity of water or slightly lower than the same into a treatment tank. CONSTITUTION:A cylindrical partition plate 4 having a perforated part in the upper part is provided to the center of the treatment tank 1 which has a funnel- shape sludge settling part 19 in the bottom and is provided with a perforated plate 2 in the upper part of the funnel. A discharge port 10 of a nozzle 6 for discharging air-liquid mixed water to be treated which supplies pressure-fed water 8 to be treated and air 7 from an air intake pipe 5 is provided in the partition plate 4. An adequate amt. of the small piece contact filter media 11 made of the synthetic resin having the specific gravity equal to the specific gravity of water or slightly lower than the same are packed into the tank 1 and an injection nozzle 17 for cleaning of the media 11 is provided in the tank 1. As a result, the treating capacity is increased and the back washing is simplified.
展开▼
