| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a biofilter device which is easily handled and shows a high nitrogen removing rate for a long time without requiring continuous addition of inflammable hydrogen donors such as methanol, in a rather small-scale site and device at a relatively low cost. SOLUTION: The biofilter device is equipped with a filter tank filled with a filter material essentially comprising fatty acids having >=10 carbon atoms or alcohols having >=14 carbon atoms, an inlet to introduce raw water to the filter tank, a discharge port to discharge the treated water from the filter tank and a mesh to prevent the filter from flowing out from the filter tank. The device may be provided with rotating vanes to agitate the filter material, an aerating cylinder to introduce air, a piston to pressurize the filter material or a duct to circulate a part of the treated water to the inlet of the raw water.</p> |
