Diffusion and Reaction in Biological Nitrification

Abstract

The effect of internal diffusional resistances on the rate of nitrification is analyzed theoretically and experimentally. A model for internal diffusion and simultaneous reaction is described, and a numerical solution is presented as an effectiveness factor chart. The intrinsic kinetics of nitrification was found to be described by the Michaelis-Menten expression. Different values of k and K_s can be observed in the same system if floc size is varied; the intrinsic values can only be observed if diffusional resistances are minimized. The effective diffusivity of nitrate through microbial floc was found to be statistically dependent on particle size.