Fixed‐Film Biomethanation Modeling

Abstract

A biofilm model incorporating diffusive mass transport and Monod kinetics to represent substrate uptake by biofilm during its growth phase, is developed, calibrated, verified, and used for estimation of minimum hydraulic‐retention time (HRT) with respect to biomethanation of water hyacinth through fixed‐film‐reactor technology. The results have been compared with those obtained through Young's Model, which incorporates the concept of effective substrate concentration in the biofilm. A graphical procedure is also developed for estimation of minimum steady‐state HRT. The variations between predicted values and experimental observations have been attributed to substrate multiplicity in real‐life situations and the need for simplistic modeling approaches an aid to design. The procedures presented in this paper could be employed for design of fixed‐film‐reactor systems for biomethanation of any substrate.