The oxidation ditch makes use of the continuous loop reaction tank as biological reaction tank, where the mixed liquid will circulate continuously in a closed aeration channel. The oxidation ditch is usually used under the condition of time-lapse aeration.
      Oxidation ditch makes use of a kind of aeration and stirring device with steering control, to deliver horizontal velocity towards the substances in the reaction tank, so as to circulate the stirred liquids in the closed channel.
       Oxidation ditch has an apparent concentration gradient in dissolving oxygen,which is especially applicable to biological nitrification and denitrification process techniques.However,it has limited effect in removing nitrogen, and almost no effect in removing phosphorus, while consumpts relatively more energy, resulting in a higher operational fee.