Groundwater Vulnerability and Potentially Toxic Elements Associated with the Iron Mining District of Ouixane (Northeast of Morocco)

International audienceThis study aims to investigate the groundwater vulnerability concerning potentially toxic elements in the vicinity of the abandoned iron mine of Ouixane (Morocco). A modified DRASTIC method (DRSTI) is proposed with satisfactory results. High vulnerability zones represent 40% of the study area, while medium and low vulnerability represent, respectively, 42% and 18% of the study area. These results have been validated by groundwater geochemical analyses of potentially toxic elements carried out in the framework of previous studies in the same area. Thus, the superposition of the waste rock and tailings map with the vulnerability map showed that the latter is located in areas of high to medium vulnerability and therefore constitutes the main cause of the deterioration of the geochemical quality of groundwater. Otherwise, the vulnerability method showed that the main parameters that significantly affect the vulnerability are: the depth of water (D), net recharge (R), and the unsaturated zone (I), while the other parameters do not significantly affect the model used and do not have much influence on the results of the vulnerability assessment. The method used allowed us to locate the most vulnerable areas to potentially metallic toxic elements pollution resulting from the abandoned iron mine of Ouixane, and it constitutes a tool for decision support and for developing effective action plans to mitigate and monitor the effects of the transfer of potentially toxic elements pollution to groundwater.</jats:p

Groundwater Vulnerability and Potentially Toxic Elements Associated with the Iron Mining District of Ouixane (Northeast of Morocco)

International audienceThis study aims to investigate the groundwater vulnerability concerning potentially toxic elements in the vicinity of the abandoned iron mine of Ouixane (Morocco). A modified DRASTIC method (DRSTI) is proposed with satisfactory results. High vulnerability zones represent 40% of the study area, while medium and low vulnerability represent, respectively, 42% and 18% of the study area. These results have been validated by groundwater geochemical analyses of potentially toxic elements carried out in the framework of previous studies in the same area. Thus, the superposition of the waste rock and tailings map with the vulnerability map showed that the latter is located in areas of high to medium vulnerability and therefore constitutes the main cause of the deterioration of the geochemical quality of groundwater. Otherwise, the vulnerability method showed that the main parameters that significantly affect the vulnerability are: the depth of water (D), net recharge (R), and the unsaturated zone (I), while the other parameters do not significantly affect the model used and do not have much influence on the results of the vulnerability assessment. The method used allowed us to locate the most vulnerable areas to potentially metallic toxic elements pollution resulting from the abandoned iron mine of Ouixane, and it constitutes a tool for decision support and for developing effective action plans to mitigate and monitor the effects of the transfer of potentially toxic elements pollution to groundwater.</jats:p

Groundwater Vulnerability and Potentially Toxic Elements Associated with the Iron Mining District of Ouixane (Northeast of Morocco)

This study aims to investigate the groundwater vulnerability concerning potentially toxic elements in the vicinity of the abandoned iron mine of Ouixane (Morocco). A modified DRASTIC method (DRSTI) is proposed with satisfactory results. High vulnerability zones represent 40% of the study area, while medium and low vulnerability represent, respectively, 42% and 18% of the study area. These results have been validated by groundwater geochemical analyses of potentially toxic elements carried out in the framework of previous studies in the same area. Thus, the superposition of the waste rock and tailings map with the vulnerability map showed that the latter is located in areas of high to medium vulnerability and therefore constitutes the main cause of the deterioration of the geochemical quality of groundwater. Otherwise, the vulnerability method showed that the main parameters that significantly affect the vulnerability are: the depth of water (D), net recharge (R), and the unsaturated zone (I), while the other parameters do not significantly affect the model used and do not have much influence on the results of the vulnerability assessment. The method used allowed us to locate the most vulnerable areas to potentially metallic toxic elements pollution resulting from the abandoned iron mine of Ouixane, and it constitutes a tool for decision support and for developing effective action plans to mitigate and monitor the effects of the transfer of potentially toxic elements pollution to groundwater

Optimisation of the chemical oxidation reduction process (CORD) on surrogate stainless steel in regards to its efficiency and secondary wastes

International audienceNuclear Power is a decarbonated technology of electrical energy generation. Using nuclear energy as a power source is currently considered as the best option in the fight against climate change. But the radioactive waste generated from nuclear power plants and their related facilities are matter of concern. Though the high level and intermediate level activity wastes are contained in small volumes (≤10%), significant volumes of lower activity wastes are generated. Metallic wastes are a major component of these radioactive wastes with about 500,000 tons expected in France alone, including 130,000 tons from steam generators. Majority of these metals are made of Stainless steel 316 alloy or Inconel 600. Under the effect of the primary circuit thermal-hydraulic constraints and irradiation, these the resulting corrosion products may be activated when close to the fuel, and be transported throughout the circuit. These products can be deposited on the surface of other metal components, causing contamination of the latter. The contamination can be adsorbed on the surface but can also diffuse in the oxide layers and sub-surface. The oxide layer is composed of an inner layer of Cr oxide under a layer of Ni and Fe oxide. Chemical decontamination is preferred due to the possibility of decontamination of difficult geometries and tube bends. In order to decontaminate these materials, it is important to dissolve the oxide layers chemically and a few micrometers of base metal where it could have diffused. An existing chemical method used to treat these materials is studied in this article, Chemical Oxidation Reduction Decontamination (CORD). Surrogate steel samples were prepared using high temperature induction heating and water vapour after sample preparation and cleaning. The oxide layer was characterised before treatment of the samples in the batch method at different concentrations and its effects are observed on the dissolution of the oxide layers. A protocol is being developed for the treatment of secondary waste effluents by multi-stage precipitation with a goal to reduce the total waste volumes and thus the volumes of ion exchange resins that would otherwise be needed

DataSheet1_Optimisation of the chemical oxidation reduction process (CORD) on surrogate stainless steel in regards to its efficiency and secondary wastes.ZIP

Nuclear Power is a decarbonated technology of electrical energy generation. Using nuclear energy as a power source is currently considered as the best option in the fight against climate change. But the radioactive waste generated from nuclear power plants and their related facilities are matter of concern. Though the high level and intermediate level activity wastes are contained in small volumes (≤10%), significant volumes of lower activity wastes are generated. Metallic wastes are a major component of these radioactive wastes with about 500,000 tons expected in France alone, including 130,000 tons from steam generators. Majority of these metals are made of Stainless steel 316 alloy or Inconel 600. Under the effect of the primary circuit thermal-hydraulic constraints and irradiation, these the resulting corrosion products may be activated when close to the fuel, and be transported throughout the circuit. These products can be deposited on the surface of other metal components, causing contamination of the latter. The contamination can be adsorbed on the surface but can also diffuse in the oxide layers and sub-surface. The oxide layer is composed of an inner layer of Cr oxide under a layer of Ni and Fe oxide. Chemical decontamination is preferred due to the possibility of decontamination of difficult geometries and tube bends. In order to decontaminate these materials, it is important to dissolve the oxide layers chemically and a few micrometers of base metal where it could have diffused. An existing chemical method used to treat these materials is studied in this article, Chemical Oxidation Reduction Decontamination (CORD). Surrogate steel samples were prepared using high temperature induction heating and water vapour after sample preparation and cleaning. The oxide layer was characterised before treatment of the samples in the batch method at different concentrations and its effects are observed on the dissolution of the oxide layers. A protocol is being developed for the treatment of secondary waste effluents by multi-stage precipitation with a goal to reduce the total waste volumes and thus the volumes of ion exchange resins that would otherwise be needed.</p

DataSheet1_Optimisation of the chemical oxidation reduction process (CORD) on surrogate stainless steel in regards to its efficiency and secondary wastes.pdf

Nuclear Power is a decarbonated technology of electrical energy generation. Using nuclear energy as a power source is currently considered as the best option in the fight against climate change. But the radioactive waste generated from nuclear power plants and their related facilities are matter of concern. Though the high level and intermediate level activity wastes are contained in small volumes (≤10%), significant volumes of lower activity wastes are generated. Metallic wastes are a major component of these radioactive wastes with about 500,000 tons expected in France alone, including 130,000 tons from steam generators. Majority of these metals are made of Stainless steel 316 alloy or Inconel 600. Under the effect of the primary circuit thermal-hydraulic constraints and irradiation, these the resulting corrosion products may be activated when close to the fuel, and be transported throughout the circuit. These products can be deposited on the surface of other metal components, causing contamination of the latter. The contamination can be adsorbed on the surface but can also diffuse in the oxide layers and sub-surface. The oxide layer is composed of an inner layer of Cr oxide under a layer of Ni and Fe oxide. Chemical decontamination is preferred due to the possibility of decontamination of difficult geometries and tube bends. In order to decontaminate these materials, it is important to dissolve the oxide layers chemically and a few micrometers of base metal where it could have diffused. An existing chemical method used to treat these materials is studied in this article, Chemical Oxidation Reduction Decontamination (CORD). Surrogate steel samples were prepared using high temperature induction heating and water vapour after sample preparation and cleaning. The oxide layer was characterised before treatment of the samples in the batch method at different concentrations and its effects are observed on the dissolution of the oxide layers. A protocol is being developed for the treatment of secondary waste effluents by multi-stage precipitation with a goal to reduce the total waste volumes and thus the volumes of ion exchange resins that would otherwise be needed.</p