A simple biofilm model of bacterial competition for attached surface

A simple biofilm model of competition in bacterial growth for an attached surface is developed. Competition for the attached surface is expressed with the crowded and detachment effects. The developed model is verified by comparing simulated results with data obtained in the experiments of batch culture of nitrifier and continuous treatment of actual sewage with biofilm reactor. This model can favorably simulate the growth competition between autotrophic and heterotrophic bacteria for the attached surface. Then some parameters for nitrification process are discussed with this model. It is clarified that the effective removal of organic matter before nitrification tank is required for effective nitrification in the biofilm reactor.