INVESTIGADORES
CONTRERAS edgardo Martin
artículos
Título:
Monitoring the biodegradability of bisphenol A and its metabolic intermediates by manometric respirometry tests
Autor/es:
FERRO OROZCO A.M.; CONTRERAS E.M.; ZARITZKY N.E.
Revista:
BIODEGRADATION
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2016
ISSN:
0923-9820
Resumen:
As a result of its wide usage in the productionof polycarbonate plastics and epoxy resins, bisphenol A (BPA) is commonlydetected in wastewaters. Recently, BPA became a major concern because itsadverse effects as an endocrine disruptor. In this work, the biodegradationkinetics of BPA and its metabolic intermediates 4-hydroxyacetophenone (4HAP), 4-hydroxybenzaldehyde (4HB) and4-hydroxybenzoic acid (4HBA) by BPA-acclimated activated sludge was studiedusing manometric respirometry (BOD) tests. For all the tested compounds, BODcurves exhibited two phases. In the first one, a fast increase of the oxygenconsumption (OC) due to the active oxidation of the substrate was obtained.Then, when the substrate was exhausted, the endogenous respiration produced aslower increase of OC. A standard Monod-model with biomass growth was used torepresent the OC profiles as a function of time. For all the tested compounds,a good agreement between the proposed model and the experimental data wasobtained. According to their biodegradation rates, the tested compoundscan be ordered as follows: BPA < 4HAP << 4HB < 4HBA. Because theoxidation rate of BPA by BPA-acclimatedactivated sludge limits the rate of the whole biodegradation pathway,the accumulation of metabolic intermediates 4HAP, 4HB, and 4HBA would benegligible. To calculate the dissolved oxygen concentration (C) during the BOD tests,the oxygen transfer coefficient (kLa) of the BOD bottles wasobtained using the sulfite method. Finally, a simple procedure to calculate theminimum dissolved oxygen concentration (Cmin) based on BOD data wasdeveloped. Calculation results demonstrated that under the tested conditions, Cvalues were high enough as not to be the limiting substrate for the microbialgrowth.