Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

    We have a manual that explains all the features 

Record number 316225
Title The influence of redox potential on the degradation of halogenated methanes
Author(s) Olivas, Y.; Dolfing, J.; Smith, G.B.
Source Environmental Toxicology and Chemistry 21 (2002)3. - ISSN 0730-7268 - p. 493 - 499.
DOI https://doi.org/10.1002/etc.5620210304
Department(s) ALTERRA Wageningen UR
Publication type Refereed Article in a scientific journal
Publication year 2002
Keyword(s) milieuchemie
Abstract To determine the influence of redox potential on the reaction mechanism and to quantify kinetics of the dechlorination by digester sludge, the test compounds trichlorofluoromethane (CFCl3), carbon tetrachloride (CCl4), and chloroform (CHCl3) were incubated in the presence of sludge and variable concentrations of reducing agent. Different sources of dehalogenation were examined, including live sludge and heat-killed sludge, and abiotic mechanisms were quantified in the absence of sludge. Batch incubations were done under redox conditions ranging from +534 to -348 mV. The highest rates for the dehalogenation of the three compounds were observed at -348 mV. The dechlorination rate of all the compounds by the heat-resistant catalysts was approximately twofold higher than the live treatments. It was proposed that the higher degradation rates by heat-killed sludge were due to the absence of physical barriers such as cell wall and cell membranes. There was no abiotic dechlorination of CFCl3, whereas CCl4 and CHCl3 were both reduced in the absence of sludge catalyst by Ti (III) citrate at ≥2.5 mM. The degradation pathways of CFCl3 and CHCl3 appeared to be only partially reductive since the production of reduced metabolites was low in comparison with the total amount of original halogenated compounds degraded. For CFCl3, the partial reductive degradation implied that different intra- and extra-cellular pathways were concurrent. The Gibbs free energy and the redox potential for the dehalogenation reactions utilizing Ti (III) citrate and acetate as electron donors are reported here for the first time.
Comments
There are no comments yet. You can post the first one!
Post a comment
 
Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.