| 摘要 |
<p>PROBLEM TO BE SOLVED: To efficiently treat organic foul water by transferring the foul water filled in an anaerobic biological filter tank in the front stage to an anaerobic biological filter tank in the rear stage, and returning a part of treated water in an anarobic biological tank in the last stage into the foul water before carrying out the filtering in the anaerobic filter tank in the front stage. SOLUTION: In a purification device constituted of anaerobic biological filter tanks 2-4 in which biological filter layers 6-8 are formed, foul water flowed from an inflow inlet 1a into an anaerobic biological filter tank 2 is passed through inside the biological filter layer 6 on which the anaerobic biological filtration is carried out, and then transferred into the anaerobic biological filter tank 3 by a transfer pump 9. The foul water is flowed down in a passage 17, and passed through in a biological filter layer 7 wherein the anaerobic biological filtration is carried out, and then fed from a transfer hole 18 into the anaerobic biological filter tank 4, and flowed down in a passage 19. Then the same anaerobic biological treatment is carried out, and the treated water is passed through an outflow weir 20, flowed into a disinfection chamber 5 and discharged, while a part of the treated water is returned to the anaerobic biological filter tank 3 by a circulating pump 10.</p> |
