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Papers by Catherine Landesman

Research paper thumbnail of Tritiated Water Diffusion in Fresh and Carbonated Cement Pastes: Effect of a drying/resaturation cycle

International audienceIn the French radioactive waste management context, cementitious materials ... more International audienceIn the French radioactive waste management context, cementitious materials will be widely used as engineered barriers, backfill materials or confinement matrices for some Intermediate-Level Long-Lives waste. In a waste disposal facility, during the construction and the operation phases, the ventilation of underground galleries/shafts will impose specific conditions (relative humidity, presence of CO2) that will modify the degree of water saturation (Sw) of cement materials (surfacial drying) and induce a potential carbonation. The aim of this study is to investigate the effect of a drying/resaturation cycle on the effective diffusion coefficient of tritiated water (HTO) in fresh and carbonated cement pastes.Samples used are disks (2 mm thick) of a CEM V/A hardened cement paste (HCP) prepared with a water to cement ratio of 0.43 and cured at least 27 months in an artificial cement pore water (ACW ; pH~13.5) [1]. The drying stage consisted of storing HCP samples ...

Research paper thumbnail of Coupled transport and chemistry in clay stone studied by advective displacement. Experiments and model

Research paper thumbnail of Redox State Determination in Hyperalkaline Solutions by Speciation of Selenium

In order to account for potential redox state desequilibrium in hyperalkaline solutions, it is ne... more In order to account for potential redox state desequilibrium in hyperalkaline solutions, it is necessary to supplement EH measurements by Pt electrodes with measurement of solution speciation of redox sensitive elements. In the present communication preparatory work for using Selenium speciation as indicator for redox states is described.

Research paper thumbnail of Influence of clay content on HTO and 36Cl transport properties in Callovo-Oxfordian clayrock : percolation experiments and modelling

Research paper thumbnail of Probing the surface reactivity of mineral phases constituting the Callovo-Oxfordian argilite by isotope exchange method

Research paper thumbnail of Study of the surface reactivity of clay mineral phases by isotope exchange

Research paper thumbnail of Evaluation of the anthropogenic influx of metal and metalloid contaminants into the Moulay Bousselham lagoon, Morocco, using chemometric methods coupled to geographical information systems

Environmental Science and Pollution Research, 2013

Superficial and cored sediment samples from the Moulay Bousselham lagoon and sub-watershed were a... more Superficial and cored sediment samples from the Moulay Bousselham lagoon and sub-watershed were analyzed for Al, Fe, Cu, Zn, Pb, Mn, Ni, Cr, As, Hg, and Cd. The temporal and spatial distributions of the main contamination sources of heavy metals were identified and described using chemometric and geographic information system (GIS) methods. Sediments from coastal lagoons near urban and agricultural areas are commonly contaminated with heavy metals, and the concentrations found in surface sediments are significantly higher than those from 50-100 years ago. The concentrations of these elements decrease sharply with depth in the sediment column, and the elements are preferentially enriched in the <2-μm-sized fraction of the sediment. The zones of enhanced risk of heavy metals were detected by means of GISbased geostatistical modeling. According to sediment pollution indices and statistical analysis, heavy metals (Pb, Cu, Ni, Zn, Cr, and Hg) that pose a risk have become largely enriched in the lagoon sediments during the recent period of agricultural intensification.

Research paper thumbnail of Alteration of vitrified intermediate level nuclear waste in alkaline media: effects of cementitious materials, pH and temperature

RSC Advances, 2018

Alteration experiments involving intermediate level nuclear waste (ILW) glass in contact with har... more Alteration experiments involving intermediate level nuclear waste (ILW) glass in contact with hardened cement paste (HCP) were performed to assess its behavior under simulated repository conditions.

Research paper thumbnail of Retention and diffusion of radioactive and toxic species on cementitious systems: Main outcome of the CEBAMA project

Applied Geochemistry, 2020

Cement-based materials are key components in radioactive waste repository barrier systems. To imp... more Cement-based materials are key components in radioactive waste repository barrier systems. To improve the available knowledge base, the European CEBAMA (Cement-based materials) project aimed to provide insight on general processes and phenomena that can be easily transferred to different applications. A bottom up approach was used to study radionuclide retention by cementitious materials, encompassing both individual cement mineral phases and hardened cement pastes. Solubility experiments were conducted with Be, Mo and Se under high pH conditions to provide realistic solubility limits and radionuclide speciation schemes as a prerequisite for meaningful adsorption studies. A number of retention mechanisms were addressed including adsorption, solid solution formation and precipitation of radionuclides within new solid phases formed during cement hydration and evolution. Sorption/desorption experiments were carried out on several anionic radionuclides and/or toxic elements which have received less attention to date, namely: Be, Mo, Tc, I, Se, Cl, Ra and 14 C. Solid solution formation between radionuclides in a range of oxidation states (Se, I and Mo) with the main aqueous components (OH À , SO 4 À 2 , Cl À) of cementitious systems on AFm phases were also investigated.

Research paper thumbnail of The Cold Region Critical Zone in Transition: Responses to Climate Warming and Land Use Change

Annual Review of Environment and Resources, 2021

Global climate warming disproportionately affects high-latitude and mountainous terrestrial ecosy... more Global climate warming disproportionately affects high-latitude and mountainous terrestrial ecosystems. Warming is accompanied by permafrost thaw, shorter winters, earlier snowmelt, more intense soil freeze-thaw cycles, drier summers, and longer fire seasons. These environmental changes in turn impact surface water and groundwater flow regimes, water quality, greenhouse gas emissions, soil stability, vegetation cover, and soil (micro)biological communities. Warming also facilitates agricultural expansion, urban growth, and natural resource development, adding growing anthropogenic pressures to cold regions’ landscapes, soil health, and biodiversity. Further advances in the predictive understanding of how cold regions’ critical zone processes, functions, and ecosystem services will continue to respond to climate warming and land use changes require multiscale monitoring technologies coupled with integrated observational and modeling tools. We highlight some of the major challenges, k...

Research paper thumbnail of Sorption of Model Radionuclides on Callovian-Oxfordian Clayey Formation

Research paper thumbnail of Adsorption and transport of polymaleic acid on Callovo-Oxfordian clay stone: batch and transport experiments

Journal of contaminant hydrology, 2014

Dissolved Organic Matter (DOM) can affect the mobility of radionuclides in pore water of clay-ric... more Dissolved Organic Matter (DOM) can affect the mobility of radionuclides in pore water of clay-rich geological formations, such as those intended to be used for nuclear waste disposal. The present work studies the adsorption and transport properties of a polycarboxylic acid, polymaleic acid (PMA, Mw=1.9kDa), on Callovo-Oxfordian argillite samples (COx). Even though this molecule is rather different from the natural organic matter found in clay rock, the study of its retention properties on both dispersed and intact samples allows assessing to which extent organic acids may undergo sorption under natural conditions (pH7) and what could be the impact on their mobility. PMA sorption and desorption were investigated in dispersed systems. The degree of sorption was measured after 1, 8 and 21days and for a range of PMA initial concentrations from 4.5×10(-7) to 1.4×10(-3)mol.L(-1). The reversibility of the sorption process was estimated by desorption experiments performed after the sorption...

Research paper thumbnail of Tritiated Water Diffusion in Fresh and Carbonated Cement Pastes: Effect of a drying/resaturation cycle

International audienceIn the French radioactive waste management context, cementitious materials ... more International audienceIn the French radioactive waste management context, cementitious materials will be widely used as engineered barriers, backfill materials or confinement matrices for some Intermediate-Level Long-Lives waste. In a waste disposal facility, during the construction and the operation phases, the ventilation of underground galleries/shafts will impose specific conditions (relative humidity, presence of CO2) that will modify the degree of water saturation (Sw) of cement materials (surfacial drying) and induce a potential carbonation. The aim of this study is to investigate the effect of a drying/resaturation cycle on the effective diffusion coefficient of tritiated water (HTO) in fresh and carbonated cement pastes.Samples used are disks (2 mm thick) of a CEM V/A hardened cement paste (HCP) prepared with a water to cement ratio of 0.43 and cured at least 27 months in an artificial cement pore water (ACW ; pH~13.5) [1]. The drying stage consisted of storing HCP samples ...

Research paper thumbnail of Coupled transport and chemistry in clay stone studied by advective displacement. Experiments and model

Research paper thumbnail of Redox State Determination in Hyperalkaline Solutions by Speciation of Selenium

In order to account for potential redox state desequilibrium in hyperalkaline solutions, it is ne... more In order to account for potential redox state desequilibrium in hyperalkaline solutions, it is necessary to supplement EH measurements by Pt electrodes with measurement of solution speciation of redox sensitive elements. In the present communication preparatory work for using Selenium speciation as indicator for redox states is described.

Research paper thumbnail of Influence of clay content on HTO and 36Cl transport properties in Callovo-Oxfordian clayrock : percolation experiments and modelling

Research paper thumbnail of Probing the surface reactivity of mineral phases constituting the Callovo-Oxfordian argilite by isotope exchange method

Research paper thumbnail of Study of the surface reactivity of clay mineral phases by isotope exchange

Research paper thumbnail of Evaluation of the anthropogenic influx of metal and metalloid contaminants into the Moulay Bousselham lagoon, Morocco, using chemometric methods coupled to geographical information systems

Environmental Science and Pollution Research, 2013

Superficial and cored sediment samples from the Moulay Bousselham lagoon and sub-watershed were a... more Superficial and cored sediment samples from the Moulay Bousselham lagoon and sub-watershed were analyzed for Al, Fe, Cu, Zn, Pb, Mn, Ni, Cr, As, Hg, and Cd. The temporal and spatial distributions of the main contamination sources of heavy metals were identified and described using chemometric and geographic information system (GIS) methods. Sediments from coastal lagoons near urban and agricultural areas are commonly contaminated with heavy metals, and the concentrations found in surface sediments are significantly higher than those from 50-100 years ago. The concentrations of these elements decrease sharply with depth in the sediment column, and the elements are preferentially enriched in the <2-μm-sized fraction of the sediment. The zones of enhanced risk of heavy metals were detected by means of GISbased geostatistical modeling. According to sediment pollution indices and statistical analysis, heavy metals (Pb, Cu, Ni, Zn, Cr, and Hg) that pose a risk have become largely enriched in the lagoon sediments during the recent period of agricultural intensification.

Research paper thumbnail of Alteration of vitrified intermediate level nuclear waste in alkaline media: effects of cementitious materials, pH and temperature

RSC Advances, 2018

Alteration experiments involving intermediate level nuclear waste (ILW) glass in contact with har... more Alteration experiments involving intermediate level nuclear waste (ILW) glass in contact with hardened cement paste (HCP) were performed to assess its behavior under simulated repository conditions.

Research paper thumbnail of Retention and diffusion of radioactive and toxic species on cementitious systems: Main outcome of the CEBAMA project

Applied Geochemistry, 2020

Cement-based materials are key components in radioactive waste repository barrier systems. To imp... more Cement-based materials are key components in radioactive waste repository barrier systems. To improve the available knowledge base, the European CEBAMA (Cement-based materials) project aimed to provide insight on general processes and phenomena that can be easily transferred to different applications. A bottom up approach was used to study radionuclide retention by cementitious materials, encompassing both individual cement mineral phases and hardened cement pastes. Solubility experiments were conducted with Be, Mo and Se under high pH conditions to provide realistic solubility limits and radionuclide speciation schemes as a prerequisite for meaningful adsorption studies. A number of retention mechanisms were addressed including adsorption, solid solution formation and precipitation of radionuclides within new solid phases formed during cement hydration and evolution. Sorption/desorption experiments were carried out on several anionic radionuclides and/or toxic elements which have received less attention to date, namely: Be, Mo, Tc, I, Se, Cl, Ra and 14 C. Solid solution formation between radionuclides in a range of oxidation states (Se, I and Mo) with the main aqueous components (OH À , SO 4 À 2 , Cl À) of cementitious systems on AFm phases were also investigated.

Research paper thumbnail of The Cold Region Critical Zone in Transition: Responses to Climate Warming and Land Use Change

Annual Review of Environment and Resources, 2021

Global climate warming disproportionately affects high-latitude and mountainous terrestrial ecosy... more Global climate warming disproportionately affects high-latitude and mountainous terrestrial ecosystems. Warming is accompanied by permafrost thaw, shorter winters, earlier snowmelt, more intense soil freeze-thaw cycles, drier summers, and longer fire seasons. These environmental changes in turn impact surface water and groundwater flow regimes, water quality, greenhouse gas emissions, soil stability, vegetation cover, and soil (micro)biological communities. Warming also facilitates agricultural expansion, urban growth, and natural resource development, adding growing anthropogenic pressures to cold regions’ landscapes, soil health, and biodiversity. Further advances in the predictive understanding of how cold regions’ critical zone processes, functions, and ecosystem services will continue to respond to climate warming and land use changes require multiscale monitoring technologies coupled with integrated observational and modeling tools. We highlight some of the major challenges, k...

Research paper thumbnail of Sorption of Model Radionuclides on Callovian-Oxfordian Clayey Formation

Research paper thumbnail of Adsorption and transport of polymaleic acid on Callovo-Oxfordian clay stone: batch and transport experiments

Journal of contaminant hydrology, 2014

Dissolved Organic Matter (DOM) can affect the mobility of radionuclides in pore water of clay-ric... more Dissolved Organic Matter (DOM) can affect the mobility of radionuclides in pore water of clay-rich geological formations, such as those intended to be used for nuclear waste disposal. The present work studies the adsorption and transport properties of a polycarboxylic acid, polymaleic acid (PMA, Mw=1.9kDa), on Callovo-Oxfordian argillite samples (COx). Even though this molecule is rather different from the natural organic matter found in clay rock, the study of its retention properties on both dispersed and intact samples allows assessing to which extent organic acids may undergo sorption under natural conditions (pH7) and what could be the impact on their mobility. PMA sorption and desorption were investigated in dispersed systems. The degree of sorption was measured after 1, 8 and 21days and for a range of PMA initial concentrations from 4.5×10(-7) to 1.4×10(-3)mol.L(-1). The reversibility of the sorption process was estimated by desorption experiments performed after the sorption...