Concentrations of atmospheric reactive mercury in Australia and emissions of reactive mercury from contaminated mine materials using cation exchange membranes
Mercury (Hg) is a pervasive and persistent environmental contaminant with a significant atmospheric cycle that results in distribution to all spheres of the environment. In the atmosphere Hg is found primarily as gaseous elemental Hg0 (GEM) but under certain scenarios reactive Hg2+(RM) compounds may...
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| Format: | Thesis |
| Language: | unknown |
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2019
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| Online Access: | https://doi.org/10.25949/19435613.v1 https://figshare.com/articles/thesis/Concentrations_of_atmospheric_reactive_mercury_in_Australia_and_emissions_of_reactive_mercury_from_contaminated_mine_materials_using_cation_exchange_membranes/19435613 |
| Summary: | Mercury (Hg) is a pervasive and persistent environmental contaminant with a significant atmospheric cycle that results in distribution to all spheres of the environment. In the atmosphere Hg is found primarily as gaseous elemental Hg0 (GEM) but under certain scenarios reactive Hg2+(RM) compounds may form a significant proportion of total atmospheric Hg. Physiochemical transformation processes play a leading role in the air-surface exchange of Hg and are a major determinant of Hg mobility and longevity within the environment, including bioavailability and biological uptake into ecosystem food webs, which constitutes the primary exposure pathway to the human population. Practical differentiation of gas and particle phase RM has proven to be a profound and lasting measurement challenge, and even the broadest distinction between GEM and RM is easily confounded. In addition to the intrinsic difficulties of measurement, data on atmospheric Hg in the Southern Hemisphere (SH) suffers the further limitation of being comparatively rare, and almost non-existent for RM. Lack of data inhibits international scientific and regulatory efforts to monitor, model, and mitigate the effects of Hg exposure to human populations. In an effort to help close some of the information gap, this study deployed a recently developed filter-based RM sampling system at two locations in Australia with existing GEM monitoring capabilities, and on board the Australian Research Vessel Investigator (RVI) during a research voyage to the East Antarctic coast. The ground-based field sites included a remote, temperate coastal site at the Cape Grim Baseline Air Pollution Station (CGBAPS) on the northwestern point of Tasmania, and a temperate urban site at Macquarie University Automatic Weather Station (MQAWS) in Sydney, New South Wales. Measurements were undertaken between November 2015 and May 2017, constituting the most extensive dataset on RM concentrations in Australia to date. As has been shown for GEM in the SH, concentrations of RM were relatively ... |
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