INVESTIGADORES
FERRO OROZCO Ana Micaela
artículos
Título:
Biological removal of hexavalent chromium: evaluation of the metabolic activity of native and Cr(VI)-acclimated activated sludge using a respirometric method
Autor/es:
ANA MICAELA FERRO OROZCO; EDGARDO MARTIN CONTRERAS; ZARITZKY NOEMÍ ELIZABET
Revista:
ENVIRONMENTAL TECHNOLOGY
Editorial:
TAYLOR & FRANCIS LTD
Referencias:
Lugar: Londres; Año: 2019
ISSN:
0959-3330
Resumen:
Hexavalent chromium becomes in one of the tops internationally concern environmental issues dueto its wide usage in several industrial activities. There are two stable oxidation states of chromium inthe environment which differ significantly on its toxicity; Cr(III) has lower solubility, mobility andlesser biological toxicity in comparison with Cr(VI). While Cr(VI) is a well-known carcinogen, Cr(III)is an essential dietary element. For this reason, most technologies focus attention on thereduction of Cr(VI) to Cr(III). On this context, the ability of microorganisms to reduce Cr(VI) to Cr(III) has gained attention. The objectives of the present work were to analyze the effect of Cr(VI)on the activated sludge community in a continuous reactor, and to evaluate the differences onthe metabolic activity of native (NAS) and Cr(VI)-acclimated activated sludge (CrAAS) using arespirometric method. Results showed that the activated sludge community had the capabilityto acclimate to the presence of Cr(VI). On the other hand, the increase of the initial Cr(VI)concentration from 0 to 100 mgCr/L leads to a decrease in the specific exogenous respirationrate (qEx) values, but this reduction was more noticeably in the case of NAS in comparison withCrAAS. The respirometric curves were well described by the proposed mathematical model. Itwas concluded that the CrAAS tolerated a Cr(VI) concentration about one order of magnitudehigher than NAS, which was positively reflected in the respiration rate first-order decay constant(kd), the specific maximum exogenous respiration rate (qExm), and the observed oxidationcoefficient (YO/S) values.