High Rate Nitrogen Removal Process by Moving Bed Biofilm Reactor “PABIO DENI”

Abstract

The necessity for nitrogen removal is increasing from the viewpoint of eutrophication control in recent years. Although a Modified activated sludge process was prevalent in the nitrogen removal process, since there are some faults such as long Hydraulic retention time (HRT), the various efficient process of replacing with this process have come to be developed and put in practical use. We put in practical use nitrogen removal process, PABIO DENI, which is the fluidized bed using the carrier elements made from polyethylene as a moving carrier elements. This process has the characteristics that the treatment in the HRT of 1/2 to 1/3 of the modified activated sludge process is possible, the high nitrogen removal efficiency is acquired at 10°C, and it can be adapted for the various forms of existing reactors, etc.
A demonstration tests confirmed efficient and high treatment capability such as a high removal ratio as 98% or above with volumetric loading 0.9 kg-NH₄-N/m³·d for nitrification and with 3.5 kg-NO₃- N/m³·d for denitrification, the nitrogen in treated water becomes below 10 mg/L even if HRT is 5 hrs.
In this report, while an outline of the principle. the structure and the treatment method of the fluidized bed nitrogen removal process is introduced, a part of the demonstration test result is reported.