[ensu] Fwd: Wed Jan 22 IES Environmental Studies seminar
- From: ENSU <utorensu@xxxxxxxx>
- To: ensu@xxxxxxxxxxxxx
- Date: Mon, 20 Jan 2003 12:48:45 -0500 (EST)
--- Mona El-Haddad <m.elhaddad@xxxxxxxxxxx> wrote: >
From: "Mona El-Haddad" <m.elhaddad@xxxxxxxxxxx>
> To: <m.elhaddad@xxxxxxxxxxx>
> Subject: Wed Jan 22 IES Environmental Studies
> seminar
> Date: Mon, 20 Jan 2003 09:47:10 -0500
>
>
> Institute for Environmental Studies
> ENVIRONMENTAL STUDIES SEMINAR SERIES
> *************************************
>
> WED JANUARY 22, 4:00 p.m.
> Room 2093 Earth Sciences Centre (Huron & Bancroft)
>
> BARBARA SHERWOOD LOLLAR, Professor, Department of
> Geology
> "NEW TOOLS FOR TRACKING GROUNDWATER CONTAMINATION"
>
> (abstract and full series below)
>
> For a map, updates, and abstracts, please see
> http://www.utoronto.ca/env/seminars/env-spring.html
>
> No registration required; all are welcome.
> **************************************
>
> ABSTRACT:
> This seminar will highlight a new field of
> environmental research: the
> application of compound specific isotope analysis
> (CSIA) to monitor and
> improve the clean-up process for groundwater
> pollution. Contaminant
> hydrogeology, or the study of pollution of
> groundwater resources, is
> widespread in both rural and urban settings and
> represents one of the
> most urgent challenges facing environmental science.
> Key organic
> (carbon-based) groundwater pollutants include
> petroleum hydrocarbons
> (from leaking underground storage tanks, leaking
> pipelines and
> installations) and chlorinated solvents (commonly
> used as manufacturing
> solvents, degreasing agents, and dry cleaning
> solutions). Organic
> contaminants such as those described above consist
> primarily of the
> elements carbon and hydrogen. Our approach uses mass
> spectrometer
> technology to measure the two different kinds of
> carbon (carbon-12 and
> carbon-13) naturally present in these compounds. It
> has been determined
> that for contaminants such as benzene (an important
> component of
> gasoline) or tetrachloroethylene (a dry cleaning
> solvent) for instance,
> contaminants from different spills may have
> different amounts of 12C
> versus 13C. An important part of our research
> involves measuring these
> differences (referred to as isotopic signatures) and
> using these
> differences to fingerprint the different sources of
> contamination. By
> this means we hope to facilitate tracking
> contamination at sites where
> more than one potential spill or source contributed
> to the
> contamination.
> Another important aspect of current research is
> based on the changes
> that take place in the ratio of light to heavy
> isotopes in compounds
> during processes such as biodegradation. For both
> petroleum hydrocarbons
> such as benzene and toluene, and for chlorinated
> solvents such as
> tetrachloroethylene and trichloroethylene,
> biodegradation plays a key
> role in remediation and clean-up at many polluted
> sites. For organic
> contaminants such as these, degradation can involve
> large and
> reproducible kinetic isotope effects, producing
> systematic changes in
> the delta 13C and 2H values of the residual
> contaminant. Examples from
> recent field applications will demonstrate that
> during both biological
> and chemical degradation, the light (12C, 1H) versus
> heavy isotope (13C,
> 2H) containing bonds are preferentially degraded,
> resulting in isotopic
> enrichment (fractionation) of the residual
> contaminant. In essence,
> bacteria breakdown or ?consume? the 12C at a faster
> rate, leaving a
> dramatic signal of their biodegradation efforts that
> we can measure to
> determine how much contaminant has been consumed and
> how much is
> remaining. In many cases, stable isotope
> fractionation during
> degradation can be modelled by a simple Rayleigh
> distillation model that
> relates the change in observed stable isotope
> compositions to the extent
> of degradation. Stable isotope analysis can
> therefore provide a direct
> indication of the effects of degradation on specific
> contaminants, as
> well as a novel independent means to quantify the
> extent of degradation
> and estimate degradation rates.
>
>
> UPCOMING SEMINARS:
>
> WED FEBRUARY 5 2003, 4;00 p.m.
> JONATHAN ABBATT, Professor, Department of Chemistry
> "The chemistry of atmospheric aerosols: impact on
> climate and air
> quality"
>
> WED FEBRUARY 12 2003, 4:00 p.m. Joint with The
> Sustainable Toronto
> project
> MARY MCGRATH, Director, Citizens Environment Watch
> and
> JOHN SORRELL, Project Manager, Technical
> Development, Centre for Applied
> Sustainability, York University
> "Monitoring for sustainability: engaging citizens in
> collecting, mapping
> and taking action on ecological data"
>
> MON MARCH 17 2003, 12:00 noon
> ** Room 432, Ramsay Wright Building, 25 Harbord St.
> **
> Joint with ECOLUNCH Seminar Series (with Botany and
> Zoology)
> (http://www.zoo.utoronto.ca)
> CHARLES HALL, Professor, Faculty of Environmental
> and Forest Biology,
> SUNY ESF, Syracuse
> "The myth of sustainable development"
> Sponsored by the Great Lakes Research Consortium
>
> WED MARCH 19 2003, 4:00 p.m. Joint with The
> Sustainable Toronto project
>
> DAVID BELL, Director of York Centre for Applied
> Sustainability, York
> University
> "Governance for sustainability"
>
> WED MARCH 26 2003, 4:00 p.m.
> ANDY KENNEY, Assistant Professor, Faculty of
> Forestry
> "The role of Toronto's urban forest in carbon
> sequestration and air
> pollution mitigation"
>
> WED APRIL 2 2003, 4:00 p.m.
> CORINNE BOONE, Managing Director, CO2e.com, Canada
> "The carbon market: what is it and how does it
> work?"
>
>
> For more information, please contact:
> Mona El-Haddad, 416-978-6526, m.elhaddad@xxxxxxxxxxx
>
______________________________________________________________________
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