Results
Title

KINETICS OF PROPIONATE CONVERSION IN ANAEROBIC CONTINUOUSLY STIRRED TANK REACTORS.

Authors

NIELSEN, H. B.; MLADENOVSKA, Z.; AHRING, B. K.

Abstract

The kinetic parameters of anaerobic propionate degradation by biomass from 7 continuously stirred tank reactors differing in temperature, hydraulic retention time and substrate composition were investigated. In substrate-depletion experiments (batch) the maximum propionate degradation rate, Amax, and the half saturation constant, Km, were initially estimated by applying the integrated Michaelis-Menten equation. Amax was in the range from 22.8 to 29.1 μmol gVS-1 h-1 while Km was in the range from 0.46-0.95 mM. In general, Amax gave a good reflection of the reactor performances. Secondly, the accuracy of the applied method was evaluated by use of radiotracer methodology. Amax was found to be 14-15% lower in the substrate-depletion experiment than in the radioisotope experiment due to endogenous propionate production. By including the endogenous propionate production, a 42-49% lower Km was estimated. The results demonstrate that the rate of endogenous substrate (propionate) production should be taken into account when estimating kinetic parameters in biomass from manure-based anaerobic reactors.

Subjects

PROPIONATES; MANURES; DYNAMICS; RADIOACTIVE tracers; BIOREACTORS; BIOMASS

Publication

Environmental Technology, 2008, Vol 29, Issue 2, p151

ISSN

0959-3330

Publication type

Academic Journal

DOI

10.1080/09593330802028535