Mobilization of Arsenite by Dissimilatory Reduction of Adsorbed Arsenate

Zobrist, Jürg; Dowdle, Philip R.; Davis, James A.; Oremland, Ronald S.

doi:10.1021/es001068h

Cited by 373 publications

(249 citation statements)

References 36 publications

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“…7 and 8). Masscheleyn et al (1991) and Zobrist et al (2000) reported from laboratory experiments that under reducing conditions part of As bound to Fe-oxyhydroxides was released before Fe implying reductive desorption from Fe-oxyhydroxides rather than reductive dissolution. Therefore, the shallow release of As in the sediments of Lake Shirokoe and Lake Yamsovey is attributed to both reductive desorption from Fe-oxyhydroxides and mobilization from OM upon oxidation.…”

Section: Arsenic and Antimonymentioning

confidence: 99%

Organic matter mineralization and trace element post-depositional redistribution in Western Siberia thermokarst lake sediments

et al. 2011

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Abstract. This study reports the very first results on highresolution sampling of sediments and their porewaters from three thermokarst (thaw) lakes representing different stages of ecosystem development located within the Nadym-Pur interfluve of the Western Siberia plain. Up to present time, the lake sediments of this and other permafrost-affected regions remain unexplored regarding their biogeochemical behavior. The aim of this study was to (i) document the early diagenesic processes in order to assess their impact on the organic carbon stored in the underlying permafrost, and (ii) characterize the post-depositional redistribution of trace elements and their impact on the water column. The estimated organic carbon (OC) stock in thermokarst lake sediments of 14 ± 2 kg m −2 is low compared to that reported for peat soils from the same region and denotes intense organic matter (OM) mineralization. Mineralization of OM in the thermokarst lake sediments proceeds under anoxic conditions in all the three lakes. In the course of the lake development, a shift in mineralization pathways from nitrate and sulfate to Fe-and Mn-oxyhydroxides as the main terminal electron acceptors in the early diagenetic reactions was suggested. This shift was likely promoted by the diagenetic consumption of nitrate and sulfate and their gradual depletion in the water column due to progressively decreasing frozen peat lixiviation occurring at the lake's borders. Trace elements were mobilized from host phases (OM and Fe-and Mn-oxyhydroxides) and partly sequestered in the sediment in the form of authigenic Fe-sulfides. Arsenic and Sb cycling was also closely linked to that of OM and Fe-and Mnoxyhydroxides. Shallow diagenetic enrichment of particulate Sb was observed in the less mature stages. As a result of auCorrespondence to: S. Audry (stephane.audry@get.obs-mip.fr) thigenic sulfide precipitation, the sediments of the early stage of ecosystem development were a sink for water column Cu, Zn, Cd, Pb and Sb. In contrast, at all stages of ecosystem development, the sediments were a source of dissolved Co, Ni and As to the water column. However, the concentrations of these trace elements remained low in the bottom waters, indicating that sorption processes on Fe-bounding particles and/or large-size organo-mineral colloids could mitigate the impact of post-depositional redistribution of toxic elements on the water column.

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Section: Arsenic and Antimonymentioning

confidence: 99%

Organic matter mineralization and trace element post-depositional redistribution in Western Siberia thermokarst lake sediments

et al. 2011

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“…Dissimilatory arsenate reduction has been reported in lab cultures using granular anaerobic digester sludge and an alumina based ABSR (16). The dissimilatory reduction and mobilization of arsenic specifically adsorbed onto the surface of ferrihydrite has also been studied (17)(18).…”

Section: Introductionmentioning

confidence: 99%

Leaching of Arsenic from Granular Ferric Hydroxide Residuals under Mature Landfill Conditions

Ghosh

Mukiibi

Sáez

et al. 2006

Environ. Sci. Technol.

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Most arsenic bearing solid residuals (ABSR) from water treatment will be disposed in non-hazardous landfills. The lack of an appropriate leaching test to predict arsenic mobilization from ABSR creates a need to evaluate the magnitude and mechanisms of arsenic release under landfill conditions. This work studies the leaching of arsenic and iron from a common ABSR, granular ferric hydroxide, in a laboratory-scale column that simulates the biological and physicochemical conditions of a mature, mixed solid waste landfill. The column operated for approximately 900 days and the mode of transport as well as chemical speciation of iron and arsenic changed with column age. Both iron and arsenic were readily mobilized under the anaerobic, reducing conditions. During the early stages of operation, most arsenic and iron leaching (80% and 65%, respectively) was associated with suspended particulate matter and iron was lost proportionately faster than arsenic. In later stages, while the rate of iron leaching declined, the arsenic leaching rate increased greater than 7-fold. The final phase was characterized by dissolved species leaching. Future work on the development of standard batch leaching tests should take into account the dominant mobilization mechanisms identified in this work: solid associated transport, reductive sorbent dissolution, and microbially mediated arsenic reduction.

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“…4), As is probably not only released due to the reduction of Fe and Mn oxides and subsequent release of associated As. The reduction of As(V) to As(III), as suggested by Zobrist et al, 21 probably also plays a significant role when sufficiently low redox potentials are being reached on day 90. This should, however, still be confirmed in future experiments.…”

Section: Relation Betweenmentioning

confidence: 87%

“…The accumulation of IC also indicates the establishment of reducing conditions regardless the presence of Fe or Mn oxide reduction. These reducing conditions might involve the reduction of As(V) to As(III) and subsequent As release which was not a result of Fe or Mn oxide reduction, as suggested by Zobrist et al 21 The fact that the correlation between As and IC is closer compared to the correlation between As and TOC moreover illustrates that the establishment of these reducing conditions is more important for As mobilisation compared to the association of As with soluble organic material. Sisr et al 44 indeed also previously observed that the addition of organic manure does not affect the leaching of As from soil in a column experiment.…”

Section: Relation Betweenmentioning

confidence: 88%

Presence and mobility of arsenic in estuarine wetland soils of the Scheldt estuary (Belgium)

et al. 2009

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We aimed to assess the presence and availability of arsenic (As) in intertidal marshes of the Scheldt estuary. Arsenic content was determined in soils sampled at 4 sampling depths in 11 marshes, together with other physicochemical characteristics. Subsequently, a greenhouse experiment was set up in which pore water arsenic (As) concentrations were measured 4 times in a 298-day period in 4 marsh soils at different sampling depths (10, 30, 60 and 90 cm) upon adjusting the water table level to 0, 40 and 80 cm below the surface of these soils. The As content in the soil varied significantly with sampling depth and location. Clay and organic matter seem to promote As accumulation in the upper soil layer (0-20 cm below the surface), whereas sulfide precipitation plays a significant role at higher sampling depths (20-100 cm below the surface). The As concentrations in the pore water of the greenhouse experiment often significantly exceeded the Flemish soil sanitation thresholds for groundwater. There were indications that As release is not only affected by the reductive dissolution of Fe/Mn oxides, but also by e.g. a direct reduction of As(V) to As(III). Below the water table, sulfide precipitation seems to lower As mobility when reducing conditions have been sufficiently established. Above the water table, sulfates and bicarbonates induce As release from the solid soil phase to the pore water.

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Mobilization of Arsenite by Dissimilatory Reduction of Adsorbed Arsenate

Cited by 373 publications

References 36 publications

Organic matter mineralization and trace element post-depositional redistribution in Western Siberia thermokarst lake sediments

Organic matter mineralization and trace element post-depositional redistribution in Western Siberia thermokarst lake sediments

Leaching of Arsenic from Granular Ferric Hydroxide Residuals under Mature Landfill Conditions

Presence and mobility of arsenic in estuarine wetland soils of the Scheldt estuary (Belgium)

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