Arsenic thermodynamic data and environmental geochemistry

Nordstrom, D. Kirk; Archer, Donald G.

doi:10.1007/0-306-47956-7_1

Cited by 127 publications

(152 citation statements)

References 0 publications

Supporting

Mentioning

144

Contrasting

Unclassified

Order By: Relevance

“…The version 3 files have been updated to provide consistency with more recent information. The resultant database files are generally consistent with the databases of WATEQ (Ball and Nordstrom, 1991) and PHREEQC (Parkhurst and Appelo, 1999), and the published data of Nordstrom and others (1990), Nordstrom and May (1996), and Nordstrom and Archer (2002). Details specific to each of the updated database files are discussed in this appendix.…”

Section: Appendix 1 Modifications To the Minteq Databasesupporting

confidence: 69%

One-Dimensional Transport with Equilibrium Chemistry (OTEQ) - A reactive transport model for streams and rivers

Runkel¹

2010

Techniques and Methods

View full text Add to dashboard Cite

Section: Appendix 1 Modifications To the Minteq Databasesupporting

confidence: 69%

One-Dimensional Transport with Equilibrium Chemistry (OTEQ) - A reactive transport model for streams and rivers

Runkel¹

2010

Techniques and Methods

View full text Add to dashboard Cite

“…At pH values above 8.0, As(III) is gradually negatively charged, changing from H 2 AsO 3 − to HAsO 3 2− and finally to AsO 3 3− . 64 Because As(III) is gradually negatively charged when the pH is above 8.0, it is reasonable that the adsorption capacity decreases considerably for pH values above 11.0. Similarly, As(V) exists as H 3 AsO 4 when the pH is below 4.0.…”

Section: Acs Applied Materials and Interfacesmentioning

confidence: 99%

Zirconia (ZrO₂) Embedded in Carbon Nanowires via Electrospinning for Efficient Arsenic Removal from Water Combined with DFT Studies

Luo

et al. 2016

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

To use zirconia (ZrO 2 ) as an efficient environmental adsorbent, it can be impregnated on a support to improve its physical properties and lower the overall cost. In this study, ZrO 2 embedded in carbon nanowires (ZCNs) is fabricated via an electrospinning method to remove arsenic (As) from water. The maximum adsorption capacity values of As(III) and As(V) on the ZCNs are 28.61 and 106.57 mg/g, respectively, at 40°C. These capacities are considerably higher than those of pure ZrO 2 (2.56 and 3.65 mg/g for As(III) and As(V), respectively) created using the same procedure as for the ZCNs. Meanwhile, the adsorption behaviors of As(III) and As(V) on the ZCNs are endothermic and pH dependent and follow the Freundlich isotherm model and pseudo-first-order kinetic model. Both As(III) and As(V) are chemisorbed onto the ZCNs, which is confirmed by a partial density of state (PDOS) analysis and Dubinin−Radushkevich (D-R) model calculations. Furthermore, the ZCNs also possess the capability to enhance or catalyze the oxidation process of As(III) to As(V) using dissolved oxygen. This result is confirmed by a batch experiment, XPS analysis and Mulliken net charge analysis. Density functional theory (DFT) calculations indicate the different configurations of As(III) and As(V) complexes on the tetragonal ZrO 2 (t-ZrO 2 )(111) and monoclinic ZrO 2 (m-ZrO 2 )(111) planes, respectively. The adsorption energy (E ad ) of As(V) is higher than that of As(III) on both the tZrO 2 (111) and m-ZrO 2 (111) planes (3.38 and 1.90 eV, respectively, for As(V) and 0.37 and 0.12 eV, respectively, for As(III)).

show abstract

“…To simplify calculations, aqueous iron-amino acid and iron-volatile organic acid complexes were suppressed; some formation of these complexes may be expected. Thioarsenites, specifically AsS(OH)(SH) − and As 3 S 4 (SH) 2− , from Nordstrom and Archer (24) were also suppressed; these data were assumed to have been superseded by thioarsenite data from Wilkin et al (26). When the Nordstrom and Archer thioarsenites were not suppressed, they appeared in much the same E h -pH region as the Wilkin thioarsenites; however, consistency between these two data sets is beyond the scope of this research.…”

Section: Geochemical Modelingmentioning

confidence: 99%

“…Arsenic-sulfide interactions are strongly pH-dependent and relatively complex (24)(25)(26). Arsenic immobilization by sulfate reduction may occur via different pathways under circumneutral pH conditions than under acidic conditions (27), as the reactions that control As solubility in the presence of sulfide are pH-dependent (26).…”

Section: Introductionmentioning

confidence: 99%

Laboratory Investigations of Enhanced Sulfate Reduction as a Groundwater Arsenic Remediation Strategy

Keimowitz

Mailloux

Cole

et al. 2007

Environ. Sci. Technol.

View full text Add to dashboard Cite

Landfills have the potential to mobilize arsenic via induction of reducing conditions in groundwater and subsequent desorption from or dissolution of arsenic-bearing iron phases. Laboratory incubation experiments were conducted with materials from a landfill where such processes are occurring. These experiments explored the potential for induced sulfate reduction to immobilize dissolved arsenic in situ. The native microbial community at this site reduced sulfate in the presence of added acetate. Acetate respiration and sulfate reduction were observed concurrent with dissolved iron concentrations initially increasing from 0.6 μM (0.03 mg L −1 ) to a maximum of 111 μM (6.1 mg L −1 ) and subsequently decreasing to 0.74 μM (0.04 mg L −1 ). Dissolved arsenic concentrations initially covaried with iron but subsequently increased again as sulfide accumulated, consistent with the formation of soluble thioarsenite complexes. Dissolved arsenic concentrations subsequently decreased again from a maximum of 2 μM (148 μg L −1 ) to 0.3 μM (22 μg L −1 ), consistent with formation of sulfide mineral phases or increased arsenic sorption at higher pH values. Disequilibrium processes may also explain this second arsenic peak. The maximum iron and arsenic concentrations observed in the lab represent conditions most equivalent to the in situ conditions. These findings indicate that enhanced sulfate reduction merits further study as a potential in situ groundwater arsenic remediation strategy at landfills and other sites with elevated arsenic in reducing groundwater.

show abstract

Arsenic thermodynamic data and environmental geochemistry

Cited by 127 publications

References 0 publications

One-Dimensional Transport with Equilibrium Chemistry (OTEQ) - A reactive transport model for streams and rivers

One-Dimensional Transport with Equilibrium Chemistry (OTEQ) - A reactive transport model for streams and rivers

Zirconia (ZrO₂) Embedded in Carbon Nanowires via Electrospinning for Efficient Arsenic Removal from Water Combined with DFT Studies

Laboratory Investigations of Enhanced Sulfate Reduction as a Groundwater Arsenic Remediation Strategy

Contact Info

Product

Resources

About

Arsenic thermodynamic data and environmental geochemistry

Cited by 127 publications

References 0 publications

One-Dimensional Transport with Equilibrium Chemistry (OTEQ) - A reactive transport model for streams and rivers

One-Dimensional Transport with Equilibrium Chemistry (OTEQ) - A reactive transport model for streams and rivers

Zirconia (ZrO2) Embedded in Carbon Nanowires via Electrospinning for Efficient Arsenic Removal from Water Combined with DFT Studies

Laboratory Investigations of Enhanced Sulfate Reduction as a Groundwater Arsenic Remediation Strategy

Contact Info

Product

Resources

About

Zirconia (ZrO₂) Embedded in Carbon Nanowires via Electrospinning for Efficient Arsenic Removal from Water Combined with DFT Studies