| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce a filter medium from clogging and to improve filtration efficiency by a method in which raw water is purified by passing horizontally in a purification tank filled with a granular functional material, and the clogged functional material is brought up by an air lift, washed, and separated from wastewater, the functional material is led to the purification tank, and the wastewater is introduced into a sludge storing tank. SOLUTION: Raw water introduced from an inflow tank flows horizontally in sequence to each purification tank, in which dirt such as solids are caught to be purified by a filter medium of a functional material 10 having different granular shapes from each other in each purification tank. Besides, the filter medium becomes clogged in sequence from the lower layer of each purification tank. By supplying compressed air to the lower end of a lift pipe 11 through a discharge pipe 25, the filter medium of the functional material 10 adherent to the solids, wastewater, and air move from the umbrella member 13 at the lower end of the lift pipe 11 into the lift pipe 11, and solid components such as sludge are separated from the filter medium and ascend at different speeds. The separated adherent solid components are introduced to a sludge storing tank through a trough 14 in a form of wastewater, and the filter medium falls into the purification tank to be reused.</p> |
