| 摘要 |
<p>PROBLEM TO BE SOLVED: To always maintain a microbial membrane of a suitable thickness on a surface of a filter material by a method wherein the filter material for physical removal is so arranged in a mode capable of scraping off the microbial membrane formed on the surface of the filter material for biological degradation in backwashing. SOLUTION: A vertical space is partitioned with a support 8 such as a stainless steel mesh or the like in a purification device 5, a filter material for biological degradation 10, in order to degradate a contaminated constituent dissolved in a bathtub water with a microbial membrane 11 formed on the surface is filled on the filter material 9. Then, a passage changeover valve is operated to reverse an inflow direction of the bathtub water into the purification device 5, the filter material 9 is wound up from down, and the microbial membrane 11 on the surface of the filter material 10 is thinned by scratching off by collision with the filter material and improval of fluidity of the filter material 10 itself owing to that collision. Further, a contaminant stuck to the filter material 9 is also simultaneously peeled off from the filter material 9 and exhausted outside via a drain pipe.</p> |
