Adsorption of EDTA and Metal–EDTA Complexes onto Goethite

Nowack, Bernd; Sigg, Laura

doi:10.1006/jcis.1996.0011

Cited by 272 publications

(188 citation statements)

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“…This may be due to the partial residues of EDTA. EDTA and metal complexes can be adsorbed onto solid soil phases, especially crystalline iron oxides (Nowack and Sigg, 1996;Voglar and Lestan, 2012b). It is known that the EDTA molecule contains multiple C and N atoms which could contribute to the results when soil organic matter and N concentration are measured.…”

Section: Metal Removal and Soil Properties Changes After Field Leachingmentioning

confidence: 99%

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Assessment of EDTA heap leaching of an agricultural soil highly contaminated with heavy metals

Hu¹,

Bingfan²,

Dong³

et al. 2014

Chemosphere

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Section: Metal Removal and Soil Properties Changes After Field Leachingmentioning

confidence: 99%

“…After EDTA leaching some metal-EDTA complexes are retained in the soil by the formation of bonds with soil iron oxides and especially goethite (Nowack and Sigg, 1996). Some of these bound complexes may be released and washed from the soil with irrigation water (Jelusic et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Assessment of EDTA heap leaching of an agricultural soil highly contaminated with heavy metals

Hu¹,

Bingfan²,

Dong³

et al. 2014

Chemosphere

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“…The interaction of metal contaminants with organic complexants may significantly influence their transport behavior i n the environment. [30][31][32] EDTA was used in this study as reactant (complexing agent) to induce and characterise iron dissolution from several materials.…”

Section: Iron Dissolution Experimentsmentioning

confidence: 99%

Testing the Suitability of Zerovalent Iron Materials for Reactive Walls

et al. 2005

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Environmental ContextGroundwater remediation is mostly a costly long-term process. In-situ remediation by permeable reactive barriers is a potential solution. For pollution by various redox sensitive contaminants, zerovalent iron (ZVI) has been proposed to immobilise or degrade dissolved pollutants in groundwater. Scrap iron materials are considered as an effective low-cost ZVI material. Due to the wide variation of scrap metal compositions, testing methods for characterising the corrosion behaviour need to be developed. AbstractZerovalent iron (ZVI) has been proposed as reactive material in permeable in-situ walls for contaminated groundwater. An economically feasible ZVI reactive wall requires cheap but efficient iron materials. From an uranium treatability study and results of iron dissolution in 0.002 M EDTA by five selected ZVI materials, it is shown that current research and field implementation is not based on a rational selection of application-specific iron metal sources.An experimental procedure is proposed which could enable a better material characterization.This procedure consists in mixing ZVI materials and reactive additives including contaminant 2 releasing materials (CRM) in long term batch experiments and characterise the contaminant concentration over the time.

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“…Subsequently, the aqueous Fe(II)-EDTA complex is rapidly transformed to the Fe(III)-EDTA complex (Santana-Casiano et al 2000), which exhibits a limited absorptivity allowing the Fe-EDTA complex to be transported away from the surface (Nowack and Sigg 1996;Wehrli et al 1989). As such, the dissolution of Amasteel is surface-controlled (not transport-controlled) and is proportional to the surface concentration of the complex that enhances dissolution (Bondietti et al 1993).…”

Section: Dependence Of Dissolution Rate On Edta Concentrationmentioning

confidence: 99%

“…Instead, the speciation of Fe(II) is controlled by the concentration of EDTA (Santana-Casiano et al 2000). Adsorption of EDTA onto goethite (Stumm 1997;Rubio and Matijevic 1979;Nowack and Sigg 1996;Nowack and Sigg 1997;Rueda et al 1985), lepidocrocite (Bondietti et al 1993;Rubio and Matijevic 1979), magnetite (Blesa et al 1984), hematite (Chang and Matijevic 1983) and hydrous ferric oxide (Nowack and Sigg 1997) Figure 5-3 illustrates the calculated dissolution rate of Amasteel in solutions with pH(23°C) = 9.0, 11.0, and 12.0 (Table 3- (Table 5-1). This suggests that complexation of aqueous iron by EDTA and hydroxyl ions at pH(23°C) = 10.0 results in further release of iron from the solid increasing the apparent dissolution rate (Chang and Matijevic 1983).…”

Section: Dependence Of Dissolution Rate On Edta Concentrationmentioning

confidence: 99%

Corrosion of Metal Inclusions In Bulk Vitrification Waste Packages

Bacon¹,

Pierce²,

Wellman³

et al. 2006

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SummaryThe primary purpose of the work reported here is to analyze the potential effect of the release of technetium (Tc) from metal inclusions in bulk vitrification (BV) waste packages once they are placed in the Integrated Disposal Facility (IDF). As part of the strategy for immobilizing waste from the underground tanks at Hanford, selected wastes will be immobilized using BV. During analyses of the glass produced in engineering-scale tests, metal inclusions were found in the glass product. This report contains the results from experiments designed to quantify the corrosion rates of metal inclusions found in the glass product from Test ES-32B (AMEC 2005) and simulations designed to compare the rate of Tc release from the metal inclusions to the release of Tc from glass produced with the BV process. Due to the probability of oxidizing conditions surrounding the waste packages in the IDF, in the simulations the Tc in the metal inclusions and the glass is conservatively assumed to be released congruently as soluble TcO 4 -. The experimental results and modeling calculations (Bacon and McGrail 2005) show that the metal corrosion rate will, under all conceivable conditions at the IDF, be dominated by the presence of the passivating layer and corrosion products on the metal particles. As a result, the release of Tc from the metal particles at the surfaces of fractures in the glass releases at a rate similar to the Tc present as a soluble salt (McGrail et al. 2003;Pierce et al. 2005). The release of the remaining Tc in the metal is controlled by the dissolution of the glass matrix.The dissolution kinetics of iron [Fe(0)] was quantified under conditions of constant dissolved O 2 [O 2 (aq)] and in solutions that minimized the formation of a passive film on the metal surface. These tests were performed to determine the forward reaction rate for the metal inclusions in the BV glass. Single-pass flow through (SPFT) tests were conducted over the pH(23°C) range from 7.0 to 12.0 and temperature range from 23°C to 90°C. The presence of EDTA minimized the formation of a passive film and Fe-bearing secondary phase(s) during testing allowing us to determine the forward dissolution rate. These results indicate that the corrosion of Fe(0) is relatively insensitive to pH and temperature and the forward rate is 3 to 4 orders of magnitude higher than when a passive film and corrosion products are present. Tests conducted with Amasteel (a low carbon steel non-radioactive surrogate) and ES-32B metal indicated that the forward dissolution rates for both metals were similar, if not identical. In other words, the presence of P and 99 Tc in the ES-32B metal appeared to have little effect on the forward dissolution rate. These results indicate that the corrosion rate of the ES-32B metal at repository relevant conditions was not significantly less than the surrogate metal. Because the effects of temperature (E a = 15 ±5 kJ/mol at pH(23°C) = 9.0 based on Fe release from ES-32B metal) and solution pH (η = -0.13 ±0.02 at 70°C based on Fe releas...

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Adsorption of EDTA and Metal–EDTA Complexes onto Goethite

Cited by 272 publications

References 18 publications

Assessment of EDTA heap leaching of an agricultural soil highly contaminated with heavy metals

Assessment of EDTA heap leaching of an agricultural soil highly contaminated with heavy metals

Testing the Suitability of Zerovalent Iron Materials for Reactive Walls

Corrosion of Metal Inclusions In Bulk Vitrification Waste Packages

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