Batch experiments

Abstract

Batch experiments were performed with a dechlorinating microbial assemblage from a bioreactor used for bioaugmentation and from a monitoring well in a bioaugmented site, three years after bioaugmentation. The culture from the monitoring well dechlorinated PCE in bottles with tested initial concentrations up to 0.2 mM. The culture from the bioreactor was able to dechlorinate PCE concentrations up to 0.5 mM, which was the inhibitory PCE concentration. Estimated PCE dechlorination rate, Rmax, was 80 μmol l-1 day-1 and the half-saturation constant, Km, was 0.33 mM. Dechlorination of the bioreactor was best fit to the Michealis-Menten equation with self inhibition. As the culture had no prior acclimatization and the bacteria were not in the laboratory adapted to PCE, the observed capability to transform PCE and deduced parameter values could be valid for contaminated field sites.