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A Passive Air Sampler for Precise, S...

McLagan, David Scott.

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A Passive Air Sampler for Precise, Spatially Distributed Atmospheric Gaseous Mercury Monitoring and Source Characterization.

Record Type:	Electronic resources : Monograph/item
Title/Author:	A Passive Air Sampler for Precise, Spatially Distributed Atmospheric Gaseous Mercury Monitoring and Source Characterization./
Author:	McLagan, David Scott.
Published:	Ann Arbor : ProQuest Dissertations & Theses, : 2018,
Description:	313 p.
Notes:	Source: Dissertation Abstracts International, Volume: 79-12(E), Section: B.
Contained By:	Dissertation Abstracts International79-12B(E).
Subject:	Environmental science. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10747484
ISBN:	9780438187399

A Passive Air Sampler for Precise, Spatially Distributed Atmospheric Gaseous Mercury Monitoring and Source Characterization.
McLagan, David Scott.

A Passive Air Sampler for Precise, Spatially Distributed Atmospheric Gaseous Mercury Monitoring and Source Characterization. - Ann Arbor : ProQuest Dissertations & Theses, 2018 - 313 p.

Source: Dissertation Abstracts International, Volume: 79-12(E), Section: B.

Thesis (Ph.D.)--University of Toronto (Canada), 2018.

This thesis describes the design, testing and implementation of a novel, inexpensive, high precision passive air sampler (PAS) for gaseous mercury (Hg) monitoring. The PAS uses a sulfur-impregnated activated carbon as a sorbent, a commercially available, radial diffusive barrier (RadielloRTM), and a protective shield that doubles as a storage and transport container. The diffusive barrier and protective shield also help reduce variability in uptake kinetics that can be caused by wind and precipitation. An initial outdoor calibration in Toronto revealed highly linear uptake over a one-year period and unprecedented precision. Small, but predictable effects on uptake kinetics caused by temperature and wind speed were determined in laboratory experiments. The diffusive barrier was also deemed reusable after cleaning. A study evaluating the accuracy of the PAS against industry standard active instrument at 20 global sites determined (i) the recommended sampling rate (volume of air stripped of gaseous Hg per unit time; 0.135 +/- 0.013 m3 day -1) that can be adjusted for the measured temperature and wind speed during each deployment, (ii) the excellent precision based uncertainty (4 +/- 3 %), and (iii) the average overall uncertainty is at most (9 +/- 6 %); a conservative measure due to inherent active instrument uncertainties. The analytical method (thermal decomposition, amalgamation, and atomic absorption spectrometry) was improved by the addition of sodium-carbonate to samples, which prolongs the life of the analytical instrument's catalyst. Two source characterization studies (at a former Hg mine and across the Greater Toronto Area) demonstrate the PAS's ability to successfully monitor concentration gradients and to estimate emissions. The results produced in this thesis are indicative of the PAS's ability to measure at both background and high concentration sites with exceptional accuracy and precision, and its potential to improve atmospheric Hg science globally.

ISBN: 9780438187399Subjects--Topical Terms:

677245
Environmental science.

A Passive Air Sampler for Precise, Spatially Distributed Atmospheric Gaseous Mercury Monitoring and Source Characterization.
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