Ion activity products of iron sulfides in groundwaters: Implications from the Choshui fan-delta, Western Taiwan

Chen, Wenfu; Liu, Tsung-Kwei

doi:10.1016/j.gca.2005.03.007

Cited by 14 publications

(8 citation statements)

References 31 publications

(51 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous work by Myrbo [2013] found low aqueous concentrations of metals other than Fe in the region, indicating that AVS measurements can be used to represent FeS (s) . Also supporting this assumption, observed pore water chemistries represent (over)saturated FeS (s) conditions based on typical solubilities of fresh FeS (s) precipitates [Berner, 1967;Helgeson, 1978;Morse et al, 1987;Davison, 1991;Chen and Liu, 2005]. Main channel and wetland samples cover a significant spread in AVS results, with no notable trends with depth or month.…”

Section: 1002/2017jg003822mentioning

confidence: 57%

Modeling hydrologic controls on sulfur processes in sulfate‐impacted wetland and stream sediments

Yourd

Johnson

et al. 2017

JGR Biogeosciences

View full text Add to dashboard Cite

Recent studies show sulfur redox processes in terrestrial settings are more important than previously considered, but much remains uncertain about how these processes respond to dynamic hydrologic conditions in natural field settings. We used field observations from a sulfate-impacted wetland and stream in the mining region of Minnesota (USA) to calibrate a reactive transport model and evaluate sulfur and coupled geochemical processes under contrasting hydrogeochemical scenarios. Simulations of different hydrological conditions showed that flux and chemistry differences between surface water and deeper groundwater strongly control hyporheic zone geochemical profiles. However, model results for the stream channel versus wetlands indicate sediment organic carbon content to be the more important driver of sulfate reduction rates. A complex nonlinear relationship between sulfate reduction rates and geochemical conditions is apparent from the model's higher sensitivity to sulfate concentrations in settings with higher organic content. Across all scenarios, simulated e − balance results unexpectedly showed that sulfate reduction dominates iron reduction, which is contrary to the traditional thermodynamic ladder but corroborates recent experimental findings by Hansel et al. (2015) that "cryptic" sulfur cycling could drive sulfate reduction in preference over iron reduction. Following the thermodynamic ladder, our models shows that high surface water sulfate slows methanogenesis in shallow sediments, but field observations suggest that sulfate reduction may not entirely suppress methane. Overall, our results show that sulfate reduction may serve as a major component making up and influencing terrestrial redox processes, with dynamic hyporheic fluxes controlling sulfate concentrations and reaction rates, especially in high organic content settings.Plain Language Summary Unlike in oceans, sulfur reactions have not been considered to play a prominent role in the biogeochemistry of terrestrial environments because of much lower concentrations, but recent studies have been showing terrestrial sulfur reactions to be more important than previously thought. These reactions often take place in wetland, stream, and lake sediments, which can contain a mix of both surface water and underlying groundwater. Our study investigated how water fluxes through these sediments can affect sulfur reactions when the surface water and groundwater chemistry differ significantly, such as through influxes of surface water sulfur from mining activities. Using field measurements and a computer model that simulates chemical reactions and water flow, we found that water flux drives water chemistry in wetland and stream sediments. This affects how rapidly sulfur reactions occur, especially in organic-rich wetland sediments. The model showed sulfur reactions to dominate over iron reactions, which contradicts classic chemical thermodynamics. Also, when water fluxes carry high sulfur concentrations into wetland sediments, sulfur reactions out compete produ...

show abstract

Section: 1002/2017jg003822mentioning

confidence: 57%

Modeling hydrologic controls on sulfur processes in sulfate‐impacted wetland and stream sediments

Yourd

Johnson

et al. 2017

JGR Biogeosciences

View full text Add to dashboard Cite

show abstract

“…However, the equilibrium constants for FeS (am) and mackinawite were obtained from Davison et al (1999) because the PHREEQC database included an error attributable to the mistake that occurred while borrowing Berner's data (Chen and Liu 2005) The equilibrium constants (log K) for the calculation of Eh were determined at the in situ temperature (11 • C) using the program Rxn from Geochemist's Workbench 8.0 (Bethke 2008) with the phreeqc.dat thermodynamic database. The equilibrium constants for FeS (am) and mackinawite were obtained from Davison et al (1999).…”

Section: Methodsmentioning

confidence: 99%

Determination of redox potential of sulfidic groundwater in unconsolidated sediments by long-term continuous in situ potentiometric measurements

Ioka

Sakai

Igarashi

et al. 2010

Environ Monit Assess

View full text Add to dashboard Cite

This study was undertaken to investigate the redox potential (Eh) of sulfidic groundwater in unconsolidated sediments. The Eh was determined by long-term (several days to several weeks) continuous in situ potentiometric measurements using a platinum (Pt) electrode. The Eh values measured in two monitoring campaigns were -259 and -202 mV, respectively. Chemical analysis of groundwater showed that the redox species in the groundwater were sulfide (S²⁻) and iron, respectively. The saturation indices calculated from the chemical analysis results indicated that FeS(am) and mainly mackinawite were close to equilibrium in the analyzed waters. Comparison of the measured Eh values with those calculated using different redox couples revealed that the Eh values measured in the first monitoring campaign were nearly equal to those calculated using HS⁻/SO₄²⁻, S²⁻/SO₄²⁻, FeS(am)/SO₄²⁻, and mackinawite/SO₄²⁻ redox couples; on the other hand, the Eh values measured in the second monitoring campaign were almost consistent with those measured using the FeS₂/SO₄²⁻ redox couple. The good fit between the measured Eh values and the theoretical calculated Eh values suggests that the sulfur system is related to the Eh value of sulfidic groundwater in unconsolidated sediments.

show abstract

“…Until more work is completed to further investigate these relationships, it may be wise to refer to dissolved sulfide measurements obtained colorimetrically as ''methylene blue sulfide.'' The existence of FeS (aq) species also complicates the determination of metal sulfide solubility products and may account for at least part of the significant spread observed in field-based calculations of ion activity products for FeS (s) recently reported by Chen and Liu (2005).…”

Section: Importance Of Metal Sulfide Clustersmentioning

confidence: 99%

Geochemistry of Flooded Underground Mine Workings Influenced by Bacterial Sulfate Reduction

Roesler¹,

Gammons

Druschel

et al. 2007

Aquat Geochem

View full text Add to dashboard Cite

Unlike the majority of the water in the flooded mine complex of Butte Montana, which includes the highly acidic Berkeley pit lake, groundwater in the flooded West Camp underground mine workings has a circum-neutral pH and contains at least 8 mM aqueous sulfide. This article examines the geochemistry and stable isotope composition of this unusual H 2 S-rich mine water, and also discusses problems related to the colorimetric analysis of sulfide in waters that contain FeS (aq) cluster compounds. The West Camp mine pool is maintained at a constant elevation by continuous pumping, with discharge water that contains elevated Mn (90 mM), Fe (16 mM), and As (1.3 mM) but otherwise low metal concentrations. Dissolved inorganic carbon in the mine water is in chemical and isotopic equilibrium with rhodochrosite in the mineralized veins. The mine water is under-saturated with mackinawite and amorphous FeS, but is supersaturated with Cu-and Zn-sulfides. However, voltammetry studies show that much of the dissolved sulfide and ferrous iron are present as FeS (aq) cluster molecules: as a result, the free H 2 S + HS À concentration of the West Camp water is poorly constrained. Concentrations of dissolved sulfide determined by colorimetry were lower than gravimetric assays obtained by AgNO 3 addition, implying that the FeS (aq) clusters are not completely extracted by the Methylene Blue reagent. In contrast, the clusters are quantitatively extracted as Ag 2 S after addition of AgNO 3 . Isotopic analysis of co-existing aqueous sulfide and sulfate confirms that the sulfide was produced by sulfate-reducing bacteria (SRB). The H 2 S-rich mine water is not confined to the immediate vicinity of the extraction well, but is also present in flooded mine shafts up to 3 km away, and in samples bailed from mine shafts at depths up to 300 m below static water level. This illustrates that SRB are well established throughout the southwestern portion of the extensive (>15 km 3 ) Butte flooded mine complex.

show abstract

Ion activity products of iron sulfides in groundwaters: Implications from the Choshui fan-delta, Western Taiwan

Cited by 14 publications

References 31 publications

Modeling hydrologic controls on sulfur processes in sulfate‐impacted wetland and stream sediments

Modeling hydrologic controls on sulfur processes in sulfate‐impacted wetland and stream sediments

Determination of redox potential of sulfidic groundwater in unconsolidated sediments by long-term continuous in situ potentiometric measurements

Geochemistry of Flooded Underground Mine Workings Influenced by Bacterial Sulfate Reduction

Contact Info

Product

Resources

About