| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To obtain a method for treating water containing suspended solids, inorganic-state nitrogen and phosphorus, in which oxidized nitrogen can be removed/decreased efficiently by sulfur denitrification being a biological reaction without being affected by suspended solids hindering a solid denitrifying substrate from exhibiting its good result and phosphoric acid and ammonia nitrogen can also be decreased easily at the same time by the action of magnesium hydroxide. <P>SOLUTION: The water containing suspended solids, inorganic-state nitrogen and phosphorus is made to pass through a pretreatment tank 1 packed with a lightweight granular material 2 and successively through a multiple treatment tank 3 packed with another lightweight granular material 4 whose surface is coated with the denitrifying substrate consisting of sulfur and an alkaline substance so that the suspended solids, inorganic-state nitrogen and phosphorus contained in the water are removed/decreased. In order to induce the denitrifying substrate to surely exhibit its good result over a long period of time, the multiple treatment tank is backwashed suitably and magnesium hydroxide is added to the multiple treatment tank so that the pH of the water to be treated becomes 8-8.5. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
