Method for the in Situ Calibration of a Passive Phosphate Sampler in Estuarine and Marine Waters
Author(s)
S. O'Brien, Dominique
Booij, Kess
Hawker, Darryl
Mueller, Jochen F.
Griffith University Author(s)
Year published
2011
Metadata
Show full item recordAbstract
Passive samplers for phosphate were calibrated in the laboratory over a range of flow velocities (0-27 cm s-1) and ionic strengths (0-0.62 mol kg-1). The observed sampling rates were between 0.006 and 0.20 L d-1. An empirical model allowed the estimation of these sampling rates with a precision of 8.5%. Passive flow monitors (PFMs), based on gypsum dissolution rates, were calibrated for the same range of flow velocities and ionic strength. Mass loss rates of the PFMs increased with increasing ionic strength. We demonstrate that this increase is quantitatively accounted for by the increased gypsum solubility at higher ionic ...
View more >Passive samplers for phosphate were calibrated in the laboratory over a range of flow velocities (0-27 cm s-1) and ionic strengths (0-0.62 mol kg-1). The observed sampling rates were between 0.006 and 0.20 L d-1. An empirical model allowed the estimation of these sampling rates with a precision of 8.5%. Passive flow monitors (PFMs), based on gypsum dissolution rates, were calibrated for the same range of flow velocities and ionic strength. Mass loss rates of the PFMs increased with increasing ionic strength. We demonstrate that this increase is quantitatively accounted for by the increased gypsum solubility at higher ionic strengths. We provide a calculation scheme for these solubilities for an environmentally relevant range of temperatures and salinities. The results imply that co-deployed PFMs can be used for estimating the flow effect on the in situ sampling rates of the phosphate samplers, and we expect that the same may hold for other passive samplers.
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View more >Passive samplers for phosphate were calibrated in the laboratory over a range of flow velocities (0-27 cm s-1) and ionic strengths (0-0.62 mol kg-1). The observed sampling rates were between 0.006 and 0.20 L d-1. An empirical model allowed the estimation of these sampling rates with a precision of 8.5%. Passive flow monitors (PFMs), based on gypsum dissolution rates, were calibrated for the same range of flow velocities and ionic strength. Mass loss rates of the PFMs increased with increasing ionic strength. We demonstrate that this increase is quantitatively accounted for by the increased gypsum solubility at higher ionic strengths. We provide a calculation scheme for these solubilities for an environmentally relevant range of temperatures and salinities. The results imply that co-deployed PFMs can be used for estimating the flow effect on the in situ sampling rates of the phosphate samplers, and we expect that the same may hold for other passive samplers.
View less >
Journal Title
Environmental Science & Technology
Volume
45
Issue
7
Copyright Statement
Self-archiving of the author-manuscript version is not yet supported by this journal. Please refer to the journal link for access to the definitive, published version or contact the author[s] for more information.
Subject
Environmental Chemistry (incl. Atmospheric Chemistry)