Development of a simplified biofilm model

Abstract

A simplified approach for analyzing the biofilm process in deriving an easy model has been presented. This simplified biofilm model formulated correlations between substrate concentration in the influent/effluent and at biofilm–liquid interface along with substrate flux and biofilm thickness. The model essentially considered the external mass transport according to Fick’s Law, steady state substrate as well as biomass balance for attached growth microorganisms. In substrate utilization, Monod growth kinetics has been followed incorporating relevant boundary conditions at the liquid–biofilm interface and at the attachment surface. The numerical solution of equations was accomplished using Runge–Kutta method and accordingly an integrated computer program was developed. The model has been successfully applied in a distinct set of trials with varying range of representative input variables. The model performance was compared with available existing methods and it was found an easy, accurate method that can be used for process design of biofilm reactor.