FIXED-FILM BIOMETHANATION MODELING

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 fixedfilm- 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. © ASCE.