CIDCA   05380
CENTRO DE INVESTIGACION Y DESARROLLO EN CRIOTECNOLOGIA DE ALIMENTOS
Unidad Ejecutora - UE
artículos
Título:
Biological Cr(VI) removal coupled with biomass growth, biomass decay, and multiple substrate limitation
Autor/es:
A. MICAELA FERRO OROZCO; CONTRERAS EDGARDO; ZARITZKY NOEMI.
Revista:
WATER RESEARCH
Editorial:
PERGAMON-ELSEVIER SCIENCE LTD
Referencias:
Lugar: Amsterdam; Año: 2011 vol. 45 p. 3034 - 3046
ISSN:
0043-1354
Resumen:
In this work, a mathematical model for the biological reduction of
Cr(VI), carbon and nitrogen sources consumption, and biomass growth under fully
aerobic conditions was developed. The model comprises three types of aerobic
heterotrophic cells (non-growing cells, growing cells with chromate reductase
activity, and growing cells that have lost the chromate reductase activity),
and five soluble compounds (organic substrate, ammonia nitrogen,
non-metabolizable soluble products, dissolved oxygen, and hexavalent chromium).
Two processes are considered responsible for the reduction of Cr(VI). The first
one is the reduction of Cr(VI) coupled with growth, the second process is
coupled with the endogenous decay of the biomass. The model was calibrated
using the results obtained in batch cultures in the absence of carbon and
nitrogen sources, using different initial Cr(VI) concentrations (0e100 mgCr L-1),
two carbon sources (cheese whey and lactose), and different initial nitrogen to
carbon ratio (0-50 mgN gCOD-1). The calibrated model was used to calculate
steady-state values of TSS, soluble COD, TAN and Cr(VI) in continuous systems,
obtaining a good agreement with the experimental data. The model also
accurately predicted the transient concentration of Cr(VI) as a function of
time in response to step changes of the inlet Cr(VI) concentration in
continuous systems