| Title | COMPARATIVE STUDY OF METHANOL, BUTYRATE AND HYDROGEN AS ELECTRON DONORS FOR LONG-TERM DECHLORINATION OF PCE IN MIXED ANAEROBIC CULTURES |
| Abstract | This study examined the ability of different electron donors (i.e., hydrogen, methanol, butyrate, and yeast extract) to sustain long-term (500 days) reductive dechlorination of tetrachloroethene (PCE) in anerobic fill and-draw bioreactors operated at 3:1 donor:PCE ratio (defined on a total-oxidation basis for the donor). Initially (i.e., until approximately day 80), the H2-fed bioreactor showed the best ability to completely dechlorinate
the dosed PCE (0.5 mmol/L) to ethene whereas, in the presence of methanol, butyric acid or no electron donor added (but low-level yeast extract), dechlorination was limited by the fermentation of the organic substrates and in turn by H2 availability. As the study progressed, the
H2-fed reactor experienced a diminishing ability to dechlorinate, while more stable dechlorinating activity was maintained in the reactors that were fed organic donors. The initial diminished ability of the H2-fed reactor to dechlorinate (after about 100 days), could be partially explained in terms of increased competition for H2 between dechlorinators and methanogens, whereas other factors such as growth-factor limitation and/or
accumulation of toxic and/or inhibitory metabolites were shown to play a role for longer incubation periods (over 500 days). In spite of decreasing activity with time, the H2-fed reactor proved to be the most effective in PCE dechlorination: after about 500 days, more than 65% of the added PCE was dechlorinated to ethene in the H2-fed reactor, versus 36%, 22%, and <1% in the methanol-fed, butyrate-fed, and control reactors, respectively. |
| Source | Biotechnology and bioengineering (Print) 91 (6), pp. 743–753 |
| Keywords | Reductive dechlorinationbioremediationDehalococcoidesmicrocosm study |
| Journal | Biotechnology and bioengineering (Print) |
| Editor | Wiley [etc.], New York, Stati Uniti d'America |
| Year | 2005 |
| Type | Articolo in rivista |
| Authors | AULENTA F., GOSSETT J., PETRANGELI M., ROSSETTI S., MAJONE M. |
| Text | 42157 2005 Reductive dechlorination bioremediation Dehalococcoides microcosm study COMPARATIVE STUDY OF METHANOL, BUTYRATE AND HYDROGEN AS ELECTRON DONORS FOR LONG TERM DECHLORINATION OF PCE IN MIXED ANAEROBIC CULTURES AULENTA F., GOSSETT J., PETRANGELI M., ROSSETTI S., MAJONE M. Water Research Institute, IRSA CNR Department of Chemistry Stanislao Cannizzaro , University of Rome La Sapienza School of Civil and Environmental Engineering, Cornell University, Ithaca, New York This study examined the ability of different electron donors i.e., hydrogen, methanol, butyrate, and yeast extract to sustain long term 500 days reductive dechlorination of tetrachloroethene PCE in anerobic fill and draw bioreactors operated at 3 1 donor PCE ratio defined on a total oxidation basis for the donor . Initially i.e., until approximately day 80 , the H2 fed bioreactor showed the best ability to completely dechlorinate the dosed PCE 0.5 mmol/L to ethene whereas, in the presence of methanol, butyric acid or no electron donor added but low level yeast extract , dechlorination was limited by the fermentation of the organic substrates and in turn by H2 availability. As the study progressed, the H2 fed reactor experienced a diminishing ability to dechlorinate, while more stable dechlorinating activity was maintained in the reactors that were fed organic donors. The initial diminished ability of the H2 fed reactor to dechlorinate after about 100 days , could be partially explained in terms of increased competition for H2 between dechlorinators and methanogens, whereas other factors such as growth factor limitation and/or accumulation of toxic and/or inhibitory metabolites were shown to play a role for longer incubation periods over 500 days . In spite of decreasing activity with time, the H2 fed reactor proved to be the most effective in PCE dechlorination after about 500 days, more than 65% of the added PCE was dechlorinated to ethene in the H2 fed reactor, versus 36%, 22%, and <1% in the methanol fed, butyrate fed, and control reactors, respectively. 91 Comparative Study of Methanol, Butyrate, and Hydrogen as Electron Donors for Long Term Dechlorination of Tetrachloroethene in Mixed Anerobic Cultures BB2005.pdf Articolo in rivista Wiley etc. 0006 3592 Biotechnology and bioengineering Print Biotechnology and bioengineering Print Biotechnol. bioeng. Print Biotechnology and bioengineering. Print Biotechnology bioengineering Print Combinatorial chemistry Print simona.rossetti ROSSETTI SIMONA TA.P07.014.005 Risanamento di acque di falda |
