2018
DOI: 10.1016/j.gca.2017.10.033
|View full text |Cite
|
Sign up to set email alerts
|

Mercury flux from salt marsh sediments: Insights from a comparison between 224Ra/228Th disequilibrium and core incubation methods

Abstract: In aquatic environments, sediments are the main location of mercury methylation. Thus, accurate quantification of methylmercury (MeHg) fluxes at the sediment-water interface is vital to understanding the biogeochemical cycling of mercury, especially the toxic MeHg species, and their bioaccumulation. Traditional approaches, such as core incubations, are difficult to maintain at in-situ conditions during assays, leading to over/underestimation of benthic fluxes. Alternatively, the 224Ra/228Th disequilibrium meth… Show more

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...
3
1
1

Citation Types

0
11
0

Year Published

2018
2018
2024
2024

Publication Types

Select...
8
1

Relationship

2
7

Authors

Journals

citations
Cited by 23 publications
(11 citation statements)
references
References 53 publications
0
11
0
Order By: Relevance
“…Different from previous studies, Cai et al () proposed a new method to investigate the mass exchange across the sediment‐water interface by evaluating the disequilibrium between 224 Ra and 228 Th on bulk sediments. This method was successfully applied to studies investigating solute transfer across the sediment‐water interface and benthic chemical flux (dissolved inorganic carbon, nutrients, and mercury) in salt marshes (Shi et al, ) or at the bottom of estuaries such as Yangtze River Estuary (Cai et al, ), Pearl River Estuary (Cai et al, ), and Jiulong River Estuary (Hong et al, ).…”
Section: Introductionmentioning
confidence: 99%
“…Different from previous studies, Cai et al () proposed a new method to investigate the mass exchange across the sediment‐water interface by evaluating the disequilibrium between 224 Ra and 228 Th on bulk sediments. This method was successfully applied to studies investigating solute transfer across the sediment‐water interface and benthic chemical flux (dissolved inorganic carbon, nutrients, and mercury) in salt marshes (Shi et al, ) or at the bottom of estuaries such as Yangtze River Estuary (Cai et al, ), Pearl River Estuary (Cai et al, ), and Jiulong River Estuary (Hong et al, ).…”
Section: Introductionmentioning
confidence: 99%
“…For Fe, this assumption is unlikely to be valid because under the typical seawater condition, Fe(II) can be rapidly oxidized into Fe(III) and subsequently be precipitated on the chamber walls, the suspended particles, the sediment surface, or within the sample vials prior to filtration (Severmann et al, 2010). Similar problems have been identified in a core incubation experiment for Hg, a redox sensitive metal like Fe (Shi et al, 2018). Moreover, the half-life of dissolved Fe (II), which describes the rate of Fe(II) loss through oxidation, is on the order of a few hours under the typical upper ocean condition (Lohan and Bruland, 2008).…”
Section: Comparison With Benthic Fe Fluxes Derived From Other Methodsmentioning
confidence: 96%
“…The solid-phase 228 Ra: 232 Th approach integrates over the half-life of 228 Ra, therein representing a mean-annual 228 Ra flux; therefore, these estimates seem reasonable at the seasonal time-scale considered here. A recent study found the traditional sediment incubation approach for 224 Ra flux determination to be similar to 224 Ra fluxes determined from 224 Ra: 228 Th disequilibrium (Shi et al, 2018). Thus, it seems that the incubations used to quantify the Ra flux from diffusion and bioirrigation are accurate, although it remains to be seen how representative these several cores are for the entirety of LIS.…”
Section: Mass Balance Sensitivitymentioning
confidence: 92%