Processes affecting the distribution of selenium in shallow groundwater of agricultural areas, western San Joaquin Valley, California

Deverel, Steven J.; Fujii, Roger

doi:10.1029/wr024i004p00516

Cited by 57 publications

(11 citation statements)

References 18 publications

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“…As a consequence, Se(VI) shows high bioavailability to crops and fish and high mobility in soils and groundwater. For instance, irrigation of Se-rich soils led to high levels of Se in drainage waters (up to 3700 µg/L), which caused a large-scale intoxication of the wildlife in the Kesterson National Wildlife refuge in California (USA) in the 1980s (Deverel and Fujii, 1988). Earlier work suggested that Se(VI) behaves like sulfate, with low sorption and high mobility (BALISTRIERI and CHAO, 1990;GOLDBERG and TRAINA, 1987;HAYES et al, 1987;NEAL and SPOSITO, 1989).…”

Section: The Environmental Problemmentioning

confidence: 99%

Electron transfer at the mineral/water interface: Selenium reduction by ferrous iron sorbed on clay

Charlet

Scheinost²,

Tournassat

et al. 2007

Geochimica et Cosmochimica Acta

183

129

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Electron transfer at the mineral/water interface: Selenium reduction by ferrous iron sorbed on clay. Geochimica et Cosmochimica Acta, Elsevier, 2007, 71 (23) , selenite was sorbed as outer-sphere sorption complex, covering only part of the positive edge sites, as verified by a structure-based MUSIC model and Se K-edge XAS (X-ray absorption spectroscopy). When selenite was added to montmorillonite previously equilibrated with Fe 2+ solution however, slow reduction of Se and formation of a solid phase was observed with Se K-edge XANES (x-ray absorption near-edge spectroscopy) and EXAFS (extended x-ray absorption finestructure) spectroscopy. Iterative transformation factor analysis of XANES and EXAFS spectra suggested that only one Se reaction product formed, which was identified as nano-particulate Se(0). Even after one month, only 75% of the initially sorbed Se(IV) was reduced to this solid species. Mössbauer spectrometry revealed that before and after addition and reduction of Se, 5% of total sorbed Fe occurred as

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Section: The Environmental Problemmentioning

confidence: 99%

Electron transfer at the mineral/water interface: Selenium reduction by ferrous iron sorbed on clay

Charlet

Scheinost²,

Tournassat

et al. 2007

Geochimica et Cosmochimica Acta

183

129

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“…The downgradient ponds at Kesterson received only periodic drainage water discharge and seasonally evaporated to dryness. Se concentrations in samples collected from these ponds did not correlate positively with evaporative concentration of major chemical species such as SO4 (Figure 3b), as has been observed elsewhere in the agricultural source area in the western San Joaquin Valley [Deverel and Fujii, 1988]. With increasing residence time in the ponds, the rate of Se loss by biological cycling [Presser and Barnes, 1984] and dimethylselenide volatilization [Cook and Bruland, 1987] outweighed any potential Se concentration due to evaporation.…”

Section: Bureau Of Reclamation and Lawrence Berkeley Laboratorymentioning

confidence: 71%

Groundwater contamination at the Kesterson Reservoir, California: 2. Geochemical parameters influencing selenium mobility

White¹,

Benson²,

Yee³

et al. 1991

Water Resources Research

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Transport of selenium in groundwater at the Kesterson Reservoir in the Central Valley of California was strongly retarded because of chemical reduction and precipitation mediated by microbial activity. Under such conditions, negative correlations were documented between aqueous Se and Fe 2+ , Mn, and HzS. Locally, the presence of oxidizing species, notably O2 and NO3, suppressed this reduction, permitting Se mobilization in the shallow aquifer. Selenate, the dominant and most oxidized form of Se, was in electrochemical disequilibrium with subordinate concentrations of selenite. Normally slow inorganic reduction rates were accelerated by microbial activity which utilizes oxidized chemical species including selenate as electron donors during the oxidation of organic matter. Two stratified redox barriers to selenium migration were documented beneath Kesterson: an underlying shallow anoxic zone underlying most of the pond bottom, characterized by high organic content and sulfate reduction, and a deeper dynamic front established by localized Oz infiltration from the overlying ponds and Fe 2+ release from aquifer materials. The reducing nature of this deeper aquifer ultimately precludes Se transport to regional groundwater. [Long et al., 1990]. The U.S. Bureau of Reclamation and the Lawrence Berkeley Laboratory, University of California, have conducted an extensive groundwater chemical monitoring program over the last 6 years at the Kesterson Reservoir. Detailed data tabulations and programmatic reports have been issued on an ongoing basis [Lawrence Berkeley Laboratory, 1987, 1988]. The present paper only attempts to summarize the chemical data in these studies and focuses primarily on determining significant geochemical processes controlling Se mobility. The paper is presented in the context of a preceding paper in this series which discusses the hydrologic and geologic framework at Kesterson and conservative solute transport [Benson et al., this issue]. The conclusions reached in this study are important for designing remedial A total of over 150 monitoring wells were chemically sampled either on a one-time or periodic basis at Kesterson. The wells, situated principally along berms within the reservoir area and also at adjacent offsite locations (Figure 1), varied in total depth between 3 and 65 m. The monitoring well completion methods have been previously described [Benson et al., this issue]. Interstitial water in the anoxic bottom sediments of the ponds were also sampled in pits dug adjacent to the pond margins. Prior to sampling, approximately three well bore volumes of water were removed from a well using high-capacity vacuum and centrifugal pumps. Final sample collection was made using a peristaltic pump connected to a 0.22-/am acetate filter. Chemical parameters including p H, Eh, alkalinity, dissolved oxygen (DO), sulfide, Fe z+, and total Fe were determined in the field. Eh measurements were made in a flow-through cell using a platinum electrode which was checked against a Zobell solution and polished immed...

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“…The tritium data serves as an indicator of residence time for ground water in the system. These studies are schematically represented in figure 3 (Deveral, and Fujii, 1988) It is apparent that irrigation waters added close to a drain have a residence time in the soil of approximately 8 years. Water added away from the drain, or to soils that are less porous will have longer residence time in the soils.…”

Section: Previous Soil Selenium Studiesmentioning

confidence: 99%

Total and extractable selenium in soils from the Lake Andes-Wagner irrigation area, South Dakota

Wilson¹,

Severson²,

Kennedy³

et al. 1990

Open-File Report

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Processes affecting the distribution of selenium in shallow groundwater of agricultural areas, western San Joaquin Valley, California

Cited by 57 publications

References 18 publications

Electron transfer at the mineral/water interface: Selenium reduction by ferrous iron sorbed on clay

Electron transfer at the mineral/water interface: Selenium reduction by ferrous iron sorbed on clay

Groundwater contamination at the Kesterson Reservoir, California: 2. Geochemical parameters influencing selenium mobility

Total and extractable selenium in soils from the Lake Andes-Wagner irrigation area, South Dakota

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