Slime Holdup, Influent BOD, and Mass Transfer in Trickling Filters

The performance of a trickling filter is described in terms of the kinetics of microbial growth, the slime holdup, the properties of the packing material, and the mass transfer characteristics of the liquid flow. Diffusional limitations in both the slime and the liquid phases, and the nonlinear dependence of the substrate uptake rate on both substrate concentration and slime thickness, have been taken into account. The appropriate analytical asymptotic expressions have been derived and the conditions under which they can be used have been identified quantitatively. The relationship between the present analysis and a number of empirical and fundamental models of trickling filter performance is explored.