Our next webinar is scheduled for Thursday June 8th, 2017 featuring Dr. Tim Mattes.

SiREM’s webinar series features guest speakers who are subject matter experts to provide the latest information on technology advances in environmental remediation and site characterization. The webinars will combine recent research and development activities for new and emerging contaminants and technologies with real word applications to characterize and remediate contaminated sites.

We hope you will join us for our next webinar:

VC Oxidizing Bacteria in Groundwater: Relationships with Geochemical Parameters and Contribution to in situ Vinyl Chloride Attenuation Rates

Dr. Tim Mattes (Associate Professor, University of Iowa) will discuss how vinyl chloride (VC) oxidizing bacteria could support an overall reductive dechlorination scheme. VC-oxidizing microbes are likely to be the methanotrophs and the etheneotrophs known to operate at low oxygen concentrations with VC oxidation processes likely significant at many VC sites that are considered anoxic or anaerobic. The presentation will discuss how VC remediation strategies should incorporate methods that track the abundance and activity of etheneotrophs as an integral feature of their remediation strategy performance assessment. Phil Dennis (Senior Manager, SiREM) will present a case study in which 13C stable isotopes and molecular genetic tools were used to better understand the possible aerobic degradation pathways of cis-1,2-dichloroethene (cDCE) and VC at a California coastal site.

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Abstract:

Generation of vinyl chloride (VC) plumes during in situ bioremediation of chloroethene contaminated groundwater is a common phenomenon. Although VC can often be further reduced to ethene, there is a potential benefit to recognizing how VC-oxidizing bacteria could support an overall reductive dechlorination scheme, particularly as sites enter the monitored natural attenuation phase. Because methane and ethene typically co-occur in a VC plume originating from anaerobic reductive dechlorination of higher chloroethenes, the two most important VC-oxidizing groups are likely to be the methanotrophs and the etheneotrophs (i.e. ethene-oxidizing bacteria). Because etheneotrophs are known to operate at oxygen concentrations well below the detection limit of most field dissolved oxygen (DO) probes we hypothesize that aerobic VC oxidation processes are significant at many sites with VC plumes that are considered anoxic or anaerobic. Chemical and molecular biology analysis of 95 groundwater samples collected from VC plumes at six contaminated sites supports the notion that simultaneous aerobic and anaerobic VC biodegradation is widespread in groundwater systems. We have also noted important correlations between the chemical and biological data that suggest etheneotrophs contribute significantly to VC biodegradation in anoxic/anaerobic groundwater. Initial analyses of cryo-core sediment samples confirm that etheneotrophs and anaerobic VC dechlorinating bacteria spatially co-exist in the subsurface. Overall, our data indicate that strategies for mitigating groundwater VC contamination should incorporate methods that track the abundance and activity of etheneotrophs as an integral feature of their remediation strategy performance assessment.

The Presenters:

Professor Tim Mattes, Ph.D., Department of Civil and Environmental Engineering, University of Iowa

Prof. Mattes received his Bachelor’s degree in Civil Engineering from The Johns Hopkins University in 1994, and his Master’s in Geography and Environmental Engineering from The Johns Hopkins University in 1995. After working for 3 years as a practicing engineer designing water and wastewater facilities, he returned to graduate school in 1998. In 2004, he received a PhD in Civil and Environmental Engineering from Cornell University working with Prof. James Gossett. Since 2004, Tim has been a faculty member in the department of Civil and Environmental Engineering at The University of Iowa, and is currently an Associate Professor. He will be promoted to the rank of Professor effective July 2017. His research focuses on bioremediation of toxic compounds such as vinyl chloride, PCBs, and explosives. He specializes in applying molecular biology tools and techniques to track the presence and activity of microorganisms mediating biodegradation of toxic compounds in the environment.

Phil Dennis, M.A.Sc., Senior Manager, SiREM.

Phil Dennis has over 25 years of work and research experience in the fields of molecular biology, microbiology and their applications to environmental remediation. Phil holds a Masters of Applied Science in Civil Engineering from the University of Toronto (2000) and an Honours Bachelor of Science in Molecular Biology and Genetics from the University of Guelph (1992). As a Senior Manager at SiREM, Phil focuses on research and development, technical marketing and, and management of molecular genetic testing services.

To view previously recorded webinars click here.