津野 洋, 宗宮 功, 西村 文武, 楠田 浩雅, 渡辺 尚之
環境工学研究論文集 31(31) 189-197 1994年
Mathematical models are developed to evaluate treatment performance in a pre-precipitation and biofilm process which is operated for phosphorus removal and nitrification as well as BOD removal. The biofilm process is a fluidized medium reactor with polyurethane foam. Treatment performance is also evaluated by fractionation method, in which pollutants are separated by particle size with filters (pore size; 105, 1.0 and 0.1 micro-meter). A distribution matrix model is developed to show the change in distribution pattern and concentration of each particle size through precipitation and sedimentation. A mathematical model developed for biofilm reactor, which can simulate the competition between autotrophic and heterotrophic bacteria with respect to attached surface of the medium, is demonstrated to predict the treatment performance (BOD removal and nitrification) by comparing the simulated results with experimental results. With these models, the pre-precipitation and biofilm process is evaluated with respect to hydraulic retention time and recovery of organic sludge by comparing with primary sedimentation and biofilm process. As a result, it is shown to shorten the hydraulic retention time and increase the organic recovery effectively.