固定化硝化細菌を適用した嫌気-無酸素-好気法のシミュレーションモデル

抄録

A simulation model was developed for a combined activated sludge and biofilm process which was developed to achieve nitrogen and phosphorus removal without extending the existing treatment facilities. The process consists of an A²O (anaerobic, anoxic and oxic) process and a biofilm process in the form of fluidized bed in the aerobic zone. In this process nitrification is carried out by the nitrifiers on the fluidized media and denitrification and phosphorus removal are performed by the activated sludge.
Firstly, a biofilm model was developed by modifying the components, biological processes and detachment mechanism of an existing model, using the experimental results of the fluidized bed process. Secondly, the biofilm model was incorporated into the IAWQ Activated Sludge Model No.2 with the addition of a mechanism of transferring detached biofilm to the activated sludge. The parameter values of this model were fitted using the data of a pilot plant during a period of no rainfall. The model was then evaluated with the pilot plant data for a period of rainfall.
The model developed for the combined activated sludge and biofilm process simulated the water quality of the pilot plant well. Necessary improvements were also discussed.