Effect of diffusion limitation and substrate inhibition on steady states of a biofilm reactor treating a single pollutant.

J Air Waste Manag Assoc. 2019 Jul 10;:

Authors: Süß M, De Visscher A

Abstract

The occurrence of multiple steady states in a toluene biodegrading, diffusion-limited biofilm under aerobic conditions was investigated by computer models: one steady-state, and one nonsteady-state. Two stable and one unstable intermediate steady-state were identified in a narrow set of combinations of parameters values. The nonsteady-state model predicts conditions that evolve to a steady state that is within 0.02-1% of the solution of the steady-state model, depending on the number of grid points used, confirming the algorithms are valid. Multiple steady states occur if, 1) a biofilm is exposed to a constant gas-phase pollution concentration, which exceeds or undershoots a certain threshold, 2) in a narrow range of parameter values and 3) provided that the pollutant degradation follows Haldane kinetics. Such a biofilm displays half-saturation (i.e., Michaelis-Menten)-like apparent ('falsified') kinetics from a concentration range starting at zero up to the occurrence of a second steady state. Multiple steady states and falsified kinetics can negatively affect a biofilter and the experimental determination of kinetic parameters, respectively.

PMID: 31290732 [PubMed - as supplied by publisher]