Migration of acidic groundwater seepage from uranium-tailings impoundments, 3. Simulation of the conceptual model with application to seepage area A

Morin, Kevin A.; Cherry, John A.

doi:10.1016/0169-7722(88)90010-1

Cited by 15 publications

(7 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A contaminant migration "flow-cell7' model was used in a study by Morin and Cherry (1988) to simulate the neutralization of a groundwater contaminant plume created by drainage from an uranium tailings impoundment. The study indicated that major ions in the plume were controlled predominantly by precipitationdissolution of the calcite-siderite solid solution, gypsum, and Al and Fe hydroxides, where acid neutralization was the result of the dissolution of one of these minerals.…”

Section: Related Investigationsmentioning

confidence: 99%

“…The development of such zonations is common in acid mine drainage-contaminated groundwater (e.g. White et al 1984, Morin and Cherry 1988, Walter and Norris 1991. The calcite content of the till aquifer is fairly low, as indicated by the low alkalinity in reference well R1 , and would be insufficient to buffer the groundwater against the flux of sulfuric acid produced by sulfide oxidation.…”

Section: Acid Neutralization By Mineral Weatheringmentioning

confidence: 99%

See 1 more Smart Citation

Metal Transport in Groundwater Contaminated by Acid Mine Drainage

Herbert¹

1994

Hydrology Research

View full text Add to dashboard Cite

Acid mine drainage from a rock dump at an abandoned mine in Dalarna, Sweden, has contaminated the groundwater and created a leachate plume characterized by low pH and high concentrations of Fe, SO4, and heavy metals. Groundwater samples have been collected in order to explain the observed spatial variations in groundwater chemistry. The mineralogy of soil samples collected at the water table has been identified by X-ray diffraction analysis In order to determine which processes may be controlling the evolution of the leachate plume, the geochemical mass-transfer model PHREEQE is used to evaluate a possible reaction pathway controlling the reaction of the leachate plume with uncontaminated groundwater and the till aquifer. The results suggest that silicate weathering and goethite precipitation are the processes primarily controlling observed pH, pe, and Fe concentrations in groundwater direct down-gradient of the rock dump. Increases in K, Na, and Al concentrations along the flow path can be attributed to the feldspar weathering while Al and SO4 concentrations further down-gradient can be controlled by the precipitation of AlOHSO4. The attenuation of heavy metal concentrations may be the result of adsorption and coprecipitation with goethite and other Fe xides.

show abstract

Section: Related Investigationsmentioning

confidence: 99%

Section: Acid Neutralization By Mineral Weatheringmentioning

confidence: 99%

Metal Transport in Groundwater Contaminated by Acid Mine Drainage

Herbert¹

1994

Hydrology Research

View full text Add to dashboard Cite

show abstract

“…The adsorption ofuranyl ion to solid substances has been studied as a mobility-limiting process, particularly with respect to sorption by Fe oxides (Payne and Waite 1991, Hsi and Langmuir 1985, Ho and Miller 1985, Tripathi 1984, Maya 1982 and phyllosilicate minerals (Borovec 1981, Tsunashirna et al 1981, Lieser et al 1992. In addition to constraining the mobility of contaminant uranium associated with mine tailings sites Copyright 9 1995, The Clay Minerals Society (Bonotto 1989, Thomson et a11986, Morin et a11982, Morin andCherry 1988), sorption reactions are thought to be an important component of the formation of economic uranium deposits (Fiala 1988, Giblin 1980. Quantitative modeling of uranyl adsorption to natural substrates has been limited to oxides and oxyhydroxides (e.g., Hsi andLangmuir 1985, Payne andWaite 1991); iron oxyhydroxides in particular have been studied because they have high adsorption capacity and are common accessory minerals or coatings in sediments and soils where uranyl adsorption reactions are significant.…”

Section: Introductionmentioning

confidence: 99%

The Influence of Uranyl Hydrolysis and Multiple Site-Binding Reactions on Adsorption of U(VI) to Montmorillonite

McKinley

1995

Clays and clay miner.

249

218

View full text Add to dashboard Cite

Abstract--Adsorption of uranyl to SWy-1 montmorillonite was evaluated experimentally and results were modeled to identify likely surface complexation reactions responsible for removal ofuranyl from solution. Uranyl was contacted with SWy-1 montmorillonite in a NaC104 electrolyte solution at three ionic strengths (I = 0.001, 0.01, 0.1), at pH 4 to 8.5, in a N2~) atmosphere. At low ionic strength, adsorption decreased from 95% at pH 4 to 75% at pH 6.8. At higher ionic strength, adsorption increased with pH from initial values less than 75%; adsorption edges for all ionic strengths coalesced above a pH of 7. A site-binding model was applied that treated SWy-1 as an aggregate of fixed-charge sites and edge sites analogous to gibbsite and silica. The concentration of fixed-charge sites was estimated as the cation exchange capacity, and non-preference exchange was assumed in calculating the contribution of fixed-charge sites to total uranyl adsorption. The concentration of edge sites was estimated by image analysis of transmission electron photomicrographs. Adsorption constants for uranyl binding to gibbsite and silica were determined by fitting to experimental data, and these adsorption constants were then used to simulate SWy-1 adsorption results. The best simulations were obtained with an ionization model in which A1OH2 + was the dominant aluminol surface species throughout the experimental range in pH. The pH-dependent aqueous speciation of uranyl was an important factor determining the magnitude of uranyl adsorption. At low ionic strength and low pH, adsorption by fixed-charge sites was predominant. The decrease in adsorption with increasing pH was caused by the formation of monovalent aqueous uranyl species, which were weakly bound to fixed-charge sites. At higher ionic strengths, competition with Na + decreased the adsorption of UOz 2+ to fixed-charge sites. At higher pH, the most significant adsorption reactions were the binding of UP22+ to A1OH and of(UO2)3(OH)5 + tO SiOH edge sites. Near-saturation of A1OH sites by UOz 1+ allowed significant contributions of SiOH sites to uranyl adsorption.

show abstract

“…The literature review shows that previous studies conducted at well characterized mine sites obtained significant discrepancy between simulated and observed values [44][45][46]. These studies reported that the lack of mineralogical characterization hinders their ability to predict fate and transport of toxic metals.…”

Section: Resultsmentioning

confidence: 99%