Microbial reductive dechlorination of trichloroethene to ethene with electrodes serving as electron donors without the external addition of redox mediators

In situ anaerobic reductive dechlorination, using slow-release electron donors, is emerging as an effective and sustainable (low-cost and low-maintenance) technology to remediate aquifers contaminated by chloroethenes. In the present study, we investigated the use of poly-β-hydroxy-butyrate (PHB), a fully biodegradable polymer, as a slow-release source of hydrogen and acetate for the reductive dechlorination of trichloroethene (TCE). Results of this study indicated that TCE dechlorination in PHB-amended microcosms was 2.3-times higher than in non-amended controls. This higher activity was explained by a higher H2 level in PHB-amended microcosms. As usual, acetate was the major sink (∼90%) of reducing equivalents available from PHB degradation, whereas no acetotrophic dechlorination was observed.

Download Full-text

A Microcosm Treatability Study for Evaluating Wood Mulch-Based Amendments as Electron Donors for Trichloroethene (TCE) Reductive Dechlorination

Water ◽

10.3390/w13141949 ◽

2021 ◽

Vol 13 (14) ◽

pp. 1949

Author(s):

Edoardo Masut ◽

Alessandro Battaglia ◽

Luca Ferioli ◽

Anna Legnani ◽

Carolina Cruz Viggi ◽

...

Keyword(s):

Electron Donor ◽

Environmental Sustainability ◽

Reductive Dechlorination ◽

Environmental Remediation ◽

Low Cost ◽

Chlorinated Solvents ◽

Electron Donors ◽

Chlorinated Ethenes ◽

Dehalococcoides Mccartyi ◽

Wood Mulch

In this study, wood mulch-based amendments were tested in a bench-scale microcosm experiment in order to assess the treatability of saturated soils and groundwater from an industrial site contaminated by chlorinated ethenes. Wood mulch was tested alone as the only electron donor in order to assess its potential for stimulating the biological reductive dechlorination. It was also tested in combination with millimetric iron filings in order to assess the ability of the additive to accelerate/improve the bioremediation process. The efficacy of the selected amendments was compared with that of unamended control microcosms. The results demonstrated that wood mulch is an effective natural and low-cost electron donor to stimulate the complete reductive dechlorination of chlorinated solvents to ethene. Being a side-product of the wood industry, mulch can be used in environmental remediation, an approach which perfectly fits the principles of circular economy and addresses the compelling needs of a sustainable and low environmental impact remediation. The efficacy of mulch was further improved by the co-presence of iron filings, which accelerated the conversion of vinyl chloride into the ethene by increasing the H2 availability rather than by catalyzing the direct abiotic dechlorination of contaminants. Chemical analyses were corroborated by biomolecular assays, which confirmed the stimulatory effect of the selected amendments on the abundance of Dehalococcoides mccartyi and related reductive dehalogenase genes. Overall, this paper further highlights the application potential and environmental sustainability of wood mulch-based amendments as low-cost electron donors for the biological treatment of chlorinated ethenes.

Download Full-text

Characterization of humins from different natural sources and the effect on microbial reductive dechlorination of pentachlorophenol

Chemosphere ◽

10.1016/j.chemosphere.2015.02.043 ◽

2015 ◽

Vol 131 ◽

pp. 110-116 ◽

Cited By ~ 30

Author(s):

Chunfang Zhang ◽

Dongdong Zhang ◽

Zhixing Xiao ◽

Zhiling Li ◽

Daisuke Suzuki ◽

...

Keyword(s):

Reductive Dechlorination ◽

Natural Sources ◽

Microbial Reductive Dechlorination

Download Full-text

Changes in Enantiomeric Fractions during Microbial Reductive Dechlorination of PCB132, PCB149, and Aroclor 1254 in Lake Hartwell Sediment Microcosms

Environmental Science & Technology ◽

10.1021/es026039g ◽

2003 ◽

Vol 37 (6) ◽

pp. 1100-1107 ◽

Cited By ~ 24

Author(s):

Usarat Pakdeesusuk ◽

W. Jack Jones ◽

Cindy M. Lee ◽

Arthur W. Garrison ◽

Walter L. O'Niell ◽

...

Keyword(s):

Reductive Dechlorination ◽

Aroclor 1254 ◽

Microbial Reductive Dechlorination ◽

Lake Hartwell

Download Full-text

Microbial reductive dechlorination of polychlorinated biphenyls in heat treated and bromoethanesulfonate treated anaerobic sediment slurries

Chemosphere ◽

10.1016/0045-6535(94)90191-0 ◽

1994 ◽

Vol 28 (12) ◽

pp. 2269-2284 ◽

Cited By ~ 7

Author(s):

William A. Williams

Keyword(s):

Polychlorinated Biphenyls ◽

Reductive Dechlorination ◽

Microbial Reductive Dechlorination ◽

Heat Treated

Download Full-text

Evaluation of the Bioelectrochemical Approach and Different Electron Donors for Biological Trichloroethylene Reductive Dichlorination

Toxics ◽

10.3390/toxics10010037 ◽

2022 ◽

Vol 10 (1) ◽

pp. 37

Author(s):

Edoardo Dell’Armi ◽

Marta Maria Rossi ◽

Lucia Taverna ◽

Marco Petrangeli Papini ◽

Marco Zeppilli

Keyword(s):

Reductive Dechlorination ◽

Molecular Hydrogen ◽

Batch Reactor ◽

Electron Donors ◽

Utilization Efficiency ◽

Batch Reactors ◽

Organic Substrates ◽

Chlorinated Aliphatic Hydrocarbons ◽

Low Solubility ◽

Dechlorination Reaction

Trichloroethylene (TCE) and more in general chlorinated aliphatic hydrocarbons (CAHs) can be removed from a contaminated matrix thanks to microorganisms able to perform the reductive dechlorination reaction (RD). Due to the lack of electron donors in the contaminated matrix, CAHs’ reductive dechlorination can be stimulated by fermentable organic substrates, which slowly release molecular hydrogen through their fermentation. In this paper, three different electron donors constituted by lactate, hydrogen, and a biocathode of a bioelectrochemical cell have been studied in TCE dechlorination batch experiments. The batch reactors evaluated in terms of reductive dechlorination rate and utilization efficiency of the electron donor reported that the bio-electrochemical system (BES) showed a lower RD rate with respect of lactate reactor (51 ± 9 µeq/d compared to 98 ± 4 µeq/d), while the direct utilization of molecular hydrogen gave a significantly lower RD rate (19 ± 8 µeq/d), due to hydrogen low solubility in liquid media. The study also gives a comparative evaluation of the different electron donors showing the capability of the bioelectrochemical system to reach comparable efficiencies with a fermentable substrate without the use of other chemicals, 10.7 ± 3.3% for BES with respect of 3.5 ± 0.2% for the lactate-fed batch reactor. This study shows the BES capability of being an alternative at classic remediation approaches.

Download Full-text