Revista internacional de contaminación ambiental
Print version ISSN 0188-4999
VAZQUEZ MORILLAS, Alethia et al. Reduction of perchloretylene and hexavalent chromium by means of FE (O) and bioestimulation of anaerobic microorganism. Rev. Int. Contam. Ambient [online]. 2007, vol.23, n.2, pp. 51-58. ISSN 0188-4999.
Fe-microorganisms interactions in and around permeable reactive barriers, for reduction of perchloroethylene and hexavalent chromium in polluted aquifers were examined. Biostimulation was done by the addition of a co-substrate for microbial communities already present in the soil. An hydrogen release compound (HRC), a commercial co-substrate which releases lactic acid at slow rates in presence of water was selected. Results show that HRC addition increases (>100 %) the reduction of PCE in iron-containing systems. Nevertheless, reductive dechlorination was not complete and caused accumulation of toxic metabolites such as trichloroethylene. For chromium reduction, bioestimulation enhanced reduction capability of the systems by 20 %. In this case, the effect was not stimulation of Cr-reducers, but the improvement of redox conditions.
Keywords : perchloroethylene; hexavalent chromium; hydrogen release compound; zero-valent iron; permeable reactive barriers.