These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.
Pubmed for Handhelds
PUBMED FOR HANDHELDS
Search MEDLINE/PubMed
Title: Acetate versus hydrogen as direct electron donors to stimulate the microbial reductive dechlorination process at chloroethene-contaminated sites. Author: He J, Sung Y, Dollhopf ME, Fathepure BZ, Tiedje JM, Löffler FE. Journal: Environ Sci Technol; 2002 Sep 15; 36(18):3945-52. PubMed ID: 12269747. Abstract: A study to evaluate the dechlorination end points and the most promising electron donors to stimulate the reductive dechlorination process at the chloroethene-contaminated Bachman Road site in Oscoda, MI, was conducted. Aquifer materials were collected from inside the plume and used to establish microcosms under a variety of electron donor conditions using chlorinated ethenes as electron acceptors. All microcosms that received an electron donor showed dechlorination activity, but the end points depended on the sampling location, indicating a heterogeneous distribution of the dechlorinating populations in the aquifer. Interestingly, several microcosms that received acetate as the only electron donor completely dechlorinated PCE to ethene. All acetate-amended microcosms rapidly converted PCE to cis-DCE, whereas PCE dechlorination in H2-fed microcosms only occurred after a pronounced lag time and after acetate had accumulated by H2/CO2 acetogenic activity. The microcosm experiments were corroborated by defined co-culture experiments, which demonstrated that H2 sustained PCE to cis-DCE dechlorination by acetotrophic populations in the presence of H2/CO2 acetogens. In sediment-free nonmethanogenic enrichment cultures derived from ethene-producing microcosms, acetate alone supported complete reductive dechlorination of chloroethenes to ethene, although the addition of H2 resulted in higher cis-DCE and VC dechlorination rates. Measurements of H2 production and consumption suggested that syntrophic acetate-oxidizing population(s) were active in the enrichment cultures. These findings demonstrated that either acetate or H2 alone can be sufficient to promote complete[Abstract] [Full Text] [Related] [New Search]