Effects of the presence of pyrite and carbonate minerals on the kinetics of the uranium release from a natural rock

Noubactep, Chicgoua; Sonnefeld, J.; Merten, D.; Heinrichs, Till; Sauter, Martin

doi:10.1007/s10967-006-0352-x

Cited by 8 publications

(4 citation statements)

References 24 publications

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“…In the PdFe system, 80% DF removal is achieved within 10 min and complete removal after 2 h. A significant fluctuation in the representative time course in the range of 20-100 min can be noticed. The large variation of the standard deviations for data corresponding to the experimental phase between 20 and 100 min can be attributed to the complexity of the removal process in the system [31,32,61]. Accordingly, the system is far from any steady state which is characterized by a better reproducibility of results.…”

Section: Resultsmentioning

confidence: 99%

“…Four main mechanisms are reported for the removal process are: (1) contaminant adsorption on Fe 0 surface or at the surface of their corrosion products [24][25][26][27][28][29]; (2) contaminant co-precipitation with metal corrosion products (MCPs) [20,30,31,32], (3) contaminant oxidation within the oxide layer [33,34], and (4) contaminant reduction including catalytic hydrodehalogenation [35][36][37]. The hart fact that oxidation of some contaminants and reduction others were reported challenges the prevailing view considering Fe 0 as a reducing agent as discussed below.…”

Section: Introductionmentioning

confidence: 99%

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Aqueous removal of diclofenac by plated elemental iron: Bimetallic systems

Ghauch

Assi

Bdeir

2010

Journal of Hazardous Materials

109

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Aqueous removal of diclofenac by plated elemental iron: Bimetallic systems

Ghauch

Assi

Bdeir

2010

Journal of Hazardous Materials

109

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“…The presence of dissolved organic matter decreases the fraction of U(IV) in the solid phase. Noubactep et al [15] discussed the effects of the presence of pyrite on the kinetics of the uranium release from a natural rock.…”

Section: Introductionmentioning

confidence: 99%

Uranium sorption characteristics onto synthesized pyrite

Luo

Liu

et al. 2015

J Radioanal Nucl Chem

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Adsorption is one of important factors associated with ore-forming process of uranium. In present paper, pyrite crystals were prepared with a hydrothermal method. Uranium adsorption was investigated with a batch method. At pH 6, the maximum sorption capacity is found to be 42.57 mg g -1 . The sorption kinetics has been successfully modeled by pseudo-second-order kinetic model. Langmuir adsorption fits well with the experimental data. Results show that U(VI) is chemically concentrated onto pyrite to form uranium mineral, and sorbed U(VI) can be partially reduced to U(V). The study provides basic data for revealing the ore-forming mechanism of uranium in the presence pyrite.

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“…Numerous 4.11 experimental investigations have been conducted to discern the mechanism of uranium uptake by calcite (Carroll et al 1992;Meece and Benninger 1993;Geipel et al 1997;Reeder et al 2000;Reeder et al 2001;Kelly et al 2003b;Savenko 2001;Elzinga et al 2004;Noubactep et al 2006;Dong et al 2005). A key result of these works has been the understanding that co-precipitation and formation of that solid solution are the likely dominant mechanisms of uranium sequestration by calcite.…”

Section: Dissolution Kinetics Of Uranium-rich Calcitementioning

confidence: 99%

300 Area Treatability Test: Laboratory Development of Polyphosphate Remediation Technology for In Situ Treatment of Uranium Contamination in the Vadose Zone and Capillary Fringe

Wellman¹,

Pierce²,

Bacon³

et al. 2008

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SummaryThe Hanford Site is a former nuclear defense production facility. A groundwater plume containing uranium, originating from a combination of purposeful discharges of wastewater to cribs, trenches, and ponds, along with some accidental leaks and spills related to nuclear fuel fabrication activities, has persisted beneath the Hanford Site 300 Area for many years. Despite the cessation of uranium releases and the removal of shallow vadose zone source materials, the remedial action objective to lower the concentration of groundwater uranium to the U. S. Environmental Protection Agency maximum contaminant level concentration of 30 µg/L has not been achieved within the anticipated 10-year time period. Some unknown amount of contamination remains in the vadose zone beneath the lower extent of the excavation activities. Additional contamination also may remain beneath buildings and facilities in the southern portion of the 300 Area, which has not been decontaminated and decommissioned. The use of polyphosphate technology for source treatment in the vadose zone and capillary fringe is expected to accelerate the natural attenuation of uranium to thermodynamically stable uranium-phosphate minerals. This effort will complement the current 300 Area treatability test being conducted within the saturated zone (e.g., 300 Area aquifer) for in situ treatment of uranium-contaminated groundwater.Polyphosphate technology has been demonstrated for in situ precipitation of phosphate phases to control the long-term fate of uranium. A critical component of the development and testing is detailed evaluation to determine if polyphosphate technology could be modified for infiltration from ground surface or some depth of excavation to stabilize source uranium phases. This report presents results from bench-scale treatability studies conducted under site-specific conditions to optimize the polyphosphate amendment for implementation of a field-scale technology demonstration to stabilize uranium within the 300 Area vadose zone and capillary fringe of the Hanford Site. Documented in this report are data related to 1) the retardation of polyphosphate as a function of water content and pore water velocity, 2) the reaction between uranium-bearing solid phases and aqueous polyphosphate remediation technology as a function of polyphosphate composition and concentration, 3) the mechanism of autunite formation via the reaction of solid-phase calcite-bound uranium and aqueous polyphosphate remediation technology, 4) the transformation mechanism and reaction kinetics between uranyl-carbonate and -silicate minerals with the polyphosphate remedy under advective conditions, and 5) the extent and rate of uranium released and immobilized as a function of polyphosphate composition and the infiltration rate of the polyphosphate remedy. Kinetic rate law parameters were determined from single-pass flow-through experiments. Pressurized unsaturated flow tests were used to determine the effect of polyphosphate composition, concentration, and infiltration rate...

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Effects of the presence of pyrite and carbonate minerals on the kinetics of the uranium release from a natural rock

Abstract: The influence of calcite, dolomite, pyrite and vaterite on the kinetics of uranium (U) release from a natural rock under relevant i.e. field conditions has been investigated.

Cited by 8 publications

References 24 publications

Aqueous removal of diclofenac by plated elemental iron: Bimetallic systems

Aqueous removal of diclofenac by plated elemental iron: Bimetallic systems

Uranium sorption characteristics onto synthesized pyrite

300 Area Treatability Test: Laboratory Development of Polyphosphate Remediation Technology for In Situ Treatment of Uranium Contamination in the Vadose Zone and Capillary Fringe

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