<p> The sulfur cycle is perhaps one of earth's most important
cycles. Biologically sulfur is the main constituent needed to
form building blocks such as amino acids. Ecologically, it
can devastate forests, lakes and ecosystems in one of it's
many forms. Industrially (and perhaps naturally) it is the
source of our acid rain problem. </p> <p> An estimation of sulfide fluxes emitted into the atmosphere
is extremely variant due to the lack of efficient means
of measuring these fluxes. Several simplistic measuring
devices have been employed to estimate the oceanic, continental
and atmospheric fluxes. Problems have arisen due to the
non-uniform distribution of sulfur sources such as industries,
volcanoes and marshlands. </p> <p> In the specific case
estimates of fluxes have
of organic volatile
been deduced and not
sulfides,
actually
measured to any great extent. The fundamental reason for this
being the lack of an efficient means of recording data in the
field to support the flux estimates. </p> <p> This study has attempted to secure the efficiency of
adsorption tubes used to sample in situ freshwater sulfide
fluxes. Optimal preparation involved using Molecular Sieve SA
(60/80 mesh) contained and activated in pyrex glass tubing
(6mm. o.d.). Proper activation occurred at 300C for 8 hours
under a constant helium flow. </p> <p> Adsorption of sulfides was by helium induced release of
gases at room/atmospheric temperatures. After 15 minutes,
the adsorption tube was recapped and stored at (-8C) for no
more than 7 days. At this time, the tubes were analyzed. </p> <p> Analysis was by GC/HECD in the laboratory. A custom made
heat desorber (at 270C), in conjunction with liquid nitrogen
and hot water sufficiently trapped the released sulfides from
the adsorption tube. Calibrated data obtained in the laboratory
provided for proper analytical interpretations of the
flux of sulfides emitted from the sample. </p> / Thesis / Bachelor of Science (BSc)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/19254 |
| Date | 04 1900 |
| Creators | Hendriks, Michelle |
| Contributors | Kramer, James, Geology |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
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