| 摘要 |
PURPOSE:To strip ammonia in biologically treated water reduced in alkalinity by aerating sewage in the coexistence of acidophilic bacteria under an acidic condition wherein the decarboxylation reaction of an HCO3<-> ion is advanced to remove HCO3<->. CONSTITUTION:Org. sewage is introduced into a tank wherein acidophil bacteria are allowed to coexist under an acidic condition to be subjected to aeration or after sewage is subjected to solid-liquid separation (a known means such as a centrifugal or natural sedimentation separation means is used) under an acidic condition, the separated solution is introduced into the tank wherein acidophil bacteria are allowed to coexist while the pH thereof is kept acidic to be subjected to aeration. As the acidophil bacteria, fungi and bacteria (e.g. Candida) are pref. designated. The alkalinity contained in the separated solution is removed by CO2 diffusion and BOD contained in the solution is biologically removed. The pH of the treated solution is made alkaline to strip ammonia contained in the solution. By this method, the addition amount of an alkali agent required in the stripping of ammonia is sharply decreased. |
