Cobalt Reactions with Montmorillonite

Hodgson, J. F.

doi:10.2136/sssaj1960.03615995002400030013x

Cited by 62 publications

(26 citation statements)

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“…The NaOAc extraction displaces exchangeable metals on clays and weak to moderately adsorbed metals on oxides (Tessier et al, 1979). It will also dissolve carbonates although siderite is not particularly vulnerable (Hodgson, 1960;Heron et al, 1994). However, because the amount of NaOAc extractable Al was approximately 65% of that extractable by 0.5 N HCl (Fig.…”

Section: The Role and Fate Of Almentioning

confidence: 99%

Dissimilatory bacterial reduction of Al-substituted goethite in subsurface sediments

Kukkadapu

Zachara

Smith

et al. 2001

Geochimica et Cosmochimica Acta

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Abstract-The microbiologic reduction of a 0.2 to 2.0 m size fraction of an Atlantic coastal plain sediment (Eatontown) was investigated using a dissimilatory Fe(III)-reducing bacterium (Shewanella putrefaciens, strain CN32) to evaluate mineralogic controls on the rate and extent of Fe(III) reduction and the resulting distribution of biogenic Fe(II). Mössbauer spectroscopy and X-ray diffraction (XRD) were used to show that the sedimentary Fe(III) oxide was Al-substituted goethite (13-17% Al) that existed as 1-to 5-m aggregates of indistinct morphology. Bioreduction experiments were performed in two buffers [HCO 3 Ϫ ; 1,4-piperazinediethansulfonic acid (PIPES)] both without and with 2,6-anthraquinone disulfonate (AQDS) as an electron shuttle. The production of biogenic Fe(II) and the distribution of Al (aqueous and sorbed) were followed over time, as was the formation of Fe(II) biominerals and physical/chemical changes to the goethite.The extent of reduction was comparable in both buffers. The reducibility (rate and extent) was enhanced by AQDS; 9% of dithionite-citrate-bicarbonate (DCB) extractable Fe(III) was reduced without AQDS whereas 15% was reduced in the presence of AQDS. XRD and Mössbauer spectroscopy were used to monitor the disposition of biogenic Fe(II) and changes to the Al-goethite. Fe(II) biomineralization was not evident by XRD. Biomineralization was observed by Mössbauer when sorbed Fe(II) concentrations exceeded a threshold value. The biomineralization products displayed Mössbauer spectra consistent with siderite FeCO 3 (HCO 3 Ϫ buffer only) and green rust . Adsorption of biogenic Fe(II) to accessory mineral phases (e.g., kaolinite) and bacterial surfaces appeared to limit biomineralization. Al evolved during reduction was sorbed, and extractable Al increased with reduction. XRD analysis indicated that neither crystallite size or the Al content of the goethite was affected by bacterial reduction, i.e., Al release was congruent with Fe(II).

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Section: The Role and Fate Of Almentioning

confidence: 99%

Dissimilatory bacterial reduction of Al-substituted goethite in subsurface sediments

Kukkadapu

Zachara

Smith

et al. 2001

Geochimica et Cosmochimica Acta

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“…Estos autores diferenciaron métodos que empleaban EDTA (Hodgson, 1960), métodos que utilizaban ácidos inorgánicos (Ray el al., 1957;Hirst y Nicholls, 1958;Arrhenius y Korkish, 1959;Hodgson, 1960), métodos que empleaban agentes reductores (Arrhenius y Korkish, 1959;Chester y Hughes, 1967) y, finalmente, métodos que aplicaban conjuntamente ácidos inorgánicos y agentes reductores (Chester y Hughes, 1967).…”

Section: Evolución Históricaunclassified

Untitled

Julián

Collado

2002

Estud. geol.

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Las metodologías de extracción química secuencial se aplican en Geología con el objetivo de determinar la especiación de los metales traza en suelos, sedimentos o rocas, información que no se puede conseguir a partir únicamente de un análisis químico convencional sobre muestra total. En la actualidad existe una amplia variedad de protocolos de extracción secuencial diferentes, sin haberse impuesto todavía uno de ellos como un método estándar plenamente aceptado.Las fracciones de metales pesados que comúnmente se suelen diferenciar en los sóli-dos mediante este tipo de metodologías son: intercambiable, asociada a carbonatos, asociada a óxidos Fe y Mn, asociada a materia orgánica y fracción residual. Los distintos protocolos existentes difieren en los reactivos empleados y también en las condiciones experimentales, todo ello dependiendo de los objetivos concretos del estudio a realizar.Las extracciones secuenciales han encontrado unos campos de aplicación muy amplios en las ciencias geológicas, sobre todo en los estudios de geoquímica ambiental en medios acuáticos (ríos, lagos, estuarios), en edafología y también en hidrología subterránea.Los protocolos de extracción secuencial adolecen, en conjunto, de una serie de problemas metodológicos de cierta envergadura y que han sido abordados por distintos autores, pudiendo destacar entre ellos la selectividad de los reactivos empleados, la propia definición operativa de estos métodos, la redistribución (o readsorción) elemental, las condiciones experimentales bajo las que se pueden ejecutar los protocolos, la escasez de materiales sólidos de referencia y, derivados de este último problema, la dificultad de validación de los distintos métodos y la evaluación de su precisión. A pesar de todos estos inconvenientes metodológicos, los procedimientos de extracción secuencial constituyen en la actualidad la mejor aproximación para describir la asociación geoquímica de los elementos traza con las diferentes fracciones de los sólidos. Palabras clave: Especiación, metales traza, redistribución, disponibilidad, geoquímica ambiental. ABSTRACTSequential chemical extraction methodologies are applied in Geological Sciences with the objective of determining the solid speciation for trace metals present in soil, sediment and rock samples. Such information is not available from a conventional chemical analysis. At the present time a wide variety of sequential protocols exists, but none of them has been imposed as an intemational standard method as yet.The fractions of solid material that these protocols usually allow to distinguish are the following: Exchangeable, carbonate, Fe-Mn oxide-hydroxide, organic, and residual. Different methods differ in the used reagents as well as in the experimental conditions, depending on the particular objectives.Sequential extraction methods are used in different fields of geological sciences, mainly in environmental geochemistry of aquatic systems (rivers, lakes, estuaries), edaphology and also in groundwater hydrology.In general, sequential extraction ...

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“…This result confirms the chemical elements in the sediments and the finding of Arrhenius and Korkish (1959). nodules (Ray et al, 1957;Hirst and Nicholls, The combined solution of 1 M NH2OH-HCl 1958; Goldberg and Arrhenius, 1958;Arrhenius in 25 % acetic acid, however, leaches about 90% and Korkish, 1959;Hodgson, 1960; Chester and of iron oxide minerals and also nearly 100% of Hughes, 1966Hughes, , 1967Takematsu, 1972; Kitano both carbonate and manganese oxides in ferro et al., 1980;Kitano and Fujiyoshi, 1980a, manganese nodules. If only 25% CH3COOH is 1980b; Kitano et al, 1981;Tomiyama and used, the entire fraction of carbonate, excluding Kitano, 1982 (Taira et al, 1981).…”

Section: Introductionmentioning

confidence: 99%

Terrestrial ferro-manganese nodules formed in limestone areas of the Ryukyu islands II. Partitioning of major and minor chemical constituents determined by selective chemical leaching technique.

1985

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Selective chemical leaching technique has been applied to the study on the partitioning of major and minor constituents into individual mineral species in ferro-manganese nodules formed in limestone areas of the Ryukyu Islands.The technique includes the use of 25% CH3COOH, 1 M NH2OH-HCl-25 % CH3COOH and 30% H202 solutions.Treatment with 25% CH3COOH solution led to the leaching of 51% of Ca, 0.6% of Fe and 1.5% of Mn. Successive leaching with 1 M NH2OH-HCl-25% CH3000H solu tion led to the leaching of 32% of Fe and almost 100% of Mn. The rate of leaching is largely dependent on the mineral components in the nodules.Minor elements are concentrated in the ferro-manganese fraction which is leached with 1 M NH2OH•HCl-25% CH3COOH solution. The rate of leaching is 100% for Co, 93% for Cu, 87% for Pb, 82% for Cd, 76% for Ni and 45% for Zn. Some parts of the elements remained insoluble in the above solutions.The remained fraction may have been associated with either stable clay lattice structure or stable oxide forms of lithogenous origins.

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Cobalt Reactions with Montmorillonite

Cited by 62 publications

References 0 publications

Dissimilatory bacterial reduction of Al-substituted goethite in subsurface sediments

Dissimilatory bacterial reduction of Al-substituted goethite in subsurface sediments

Untitled

Terrestrial ferro-manganese nodules formed in limestone areas of the Ryukyu islands II. Partitioning of major and minor chemical constituents determined by selective chemical leaching technique.

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