Matches in SemOpenAlex for { <https://semopenalex.org/work/W4386481289> ?p ?o ?g. }
Showing items 1 to 80 of
80
with 100 items per page.
- W4386481289 endingPage "146" @default.
- W4386481289 startingPage "145" @default.
- W4386481289 abstract "Abstract. In various countries such as Belgium and Germany, deep clay formations are investigated as potential host rock to dispose of radioactive waste. Intermediate-level long-lived bituminised waste, produced from spent fuel reprocessing, is currently foreseen to be disposed of in such a deep repository. This type of waste typically contains large amounts of salts embedded in an organic matrix, of which NaNO3 is the most prevalent. NaNO3, along with radionuclides immobilised in the bitumen matrix, will slowly dissolve and leach out into the surrounding host rock. The transport and reactivity of nitrate in a deep clay formation, in the presence and absence of electron donors coming from bituminised waste (i.e. acetate, H2), has been studied extensively inside anoxic and water-saturated chambers in the clay in the Bitumen–Nitrate–Clay interaction (BN) experiment. This in situ experiment in Opalinus clay is located in the Mont Terri rock laboratory (Switzerland). The effect of a nitrate plume on redox-sensitive radionuclides is also studied with stable selenium in selenate form as a proxy for 79Se, an important fission product for the long-term dose to humans. The BN experiment consists of a vertical borehole containing three packed-off intervals, in contact with the surrounding clay through cylindrical sintered stainless steel filter screens. The intervals are saturated with artificial Opalinus clay pore water at a pH between 7.5 and 8, containing all major ions at concentrations specific to the location of the BN experiment but without natural organic matter. Each interval is connected to a water circulation system with a gear pump, a flow meter and water sampling containers. This ensures a chemically well-mixed solution, constant water flow and easy sampling of the interval solutions under anoxic conditions. Water samples are regularly taken to assess the chemical composition and the microbial population in the intervals. An online UV spectrophotometer and pH and redox electrodes are installed in the water circuit of the intervals, to continuously monitor the nitrate and nitrite concentrations, pH and Eh. A given solution can be injected into the intervals to follow up redox reactions affecting nitrate and selenate in situ, in the presence or absence of additional electron donors. From 2011 to 2019, several injections with nitrate were performed in the intervals to investigate the biogeochemical reactivity of nitrate in the borehole and clay. These tests showed microbial reduction of nitrate, using electron donors from Opalinus clay (e.g. dissolved organic matter or pyrite). Nitrite and nitrogenous gases were formed. Pulses of electron donors (acetate or H2) boosted the microbial activity and nitrate reduction rate. From 2019 until now, injection tests with selenate, with and without nitrate, have been performed. These tests showed clearly that the presence of nitrate, a stronger oxidiser, inhibited the microbial reduction of selenate. In the absence of nitrate, the microbial population was able to reduce selenate to selenite and more reduced Se species. The results obtained in this in situ experiment will be summarised in this work, addressing questions concerning the effect of biogeochemical perturbations of the clay on the migration of redox-sensitive radionuclides." @default.
- W4386481289 created "2023-09-07" @default.
- W4386481289 creator A5029593858 @default.
- W4386481289 creator A5033162573 @default.
- W4386481289 creator A5040699732 @default.
- W4386481289 creator A5049154360 @default.
- W4386481289 creator A5049798853 @default.
- W4386481289 creator A5054716392 @default.
- W4386481289 creator A5073264358 @default.
- W4386481289 creator A5073823170 @default.
- W4386481289 creator A5079906025 @default.
- W4386481289 creator A5081223888 @default.
- W4386481289 creator A5083150917 @default.
- W4386481289 creator A5086413449 @default.
- W4386481289 creator A5090666664 @default.
- W4386481289 date "2023-09-06" @default.
- W4386481289 modified "2023-10-14" @default.
- W4386481289 title "A long-running in situ experiment in clay: 12 years of the Bitumen–Nitrate–Clay interaction experiment at Mont Terri rock laboratory" @default.
- W4386481289 doi "https://doi.org/10.5194/sand-2-145-2023" @default.
- W4386481289 hasPublicationYear "2023" @default.
- W4386481289 type Work @default.
- W4386481289 citedByCount "0" @default.
- W4386481289 crossrefType "journal-article" @default.
- W4386481289 hasAuthorship W4386481289A5029593858 @default.
- W4386481289 hasAuthorship W4386481289A5033162573 @default.
- W4386481289 hasAuthorship W4386481289A5040699732 @default.
- W4386481289 hasAuthorship W4386481289A5049154360 @default.
- W4386481289 hasAuthorship W4386481289A5049798853 @default.
- W4386481289 hasAuthorship W4386481289A5054716392 @default.
- W4386481289 hasAuthorship W4386481289A5073264358 @default.
- W4386481289 hasAuthorship W4386481289A5073823170 @default.
- W4386481289 hasAuthorship W4386481289A5079906025 @default.
- W4386481289 hasAuthorship W4386481289A5081223888 @default.
- W4386481289 hasAuthorship W4386481289A5083150917 @default.
- W4386481289 hasAuthorship W4386481289A5086413449 @default.
- W4386481289 hasAuthorship W4386481289A5090666664 @default.
- W4386481289 hasBestOaLocation W43864812891 @default.
- W4386481289 hasConcept C107872376 @default.
- W4386481289 hasConcept C108970007 @default.
- W4386481289 hasConcept C127313418 @default.
- W4386481289 hasConcept C13965031 @default.
- W4386481289 hasConcept C178790620 @default.
- W4386481289 hasConcept C185592680 @default.
- W4386481289 hasConcept C199289684 @default.
- W4386481289 hasConcept C2776384668 @default.
- W4386481289 hasConcept C39432304 @default.
- W4386481289 hasConcept C40212044 @default.
- W4386481289 hasConcept C48743137 @default.
- W4386481289 hasConcept C89690796 @default.
- W4386481289 hasConceptScore W4386481289C107872376 @default.
- W4386481289 hasConceptScore W4386481289C108970007 @default.
- W4386481289 hasConceptScore W4386481289C127313418 @default.
- W4386481289 hasConceptScore W4386481289C13965031 @default.
- W4386481289 hasConceptScore W4386481289C178790620 @default.
- W4386481289 hasConceptScore W4386481289C185592680 @default.
- W4386481289 hasConceptScore W4386481289C199289684 @default.
- W4386481289 hasConceptScore W4386481289C2776384668 @default.
- W4386481289 hasConceptScore W4386481289C39432304 @default.
- W4386481289 hasConceptScore W4386481289C40212044 @default.
- W4386481289 hasConceptScore W4386481289C48743137 @default.
- W4386481289 hasConceptScore W4386481289C89690796 @default.
- W4386481289 hasLocation W43864812891 @default.
- W4386481289 hasOpenAccess W4386481289 @default.
- W4386481289 hasPrimaryLocation W43864812891 @default.
- W4386481289 hasRelatedWork W1514345120 @default.
- W4386481289 hasRelatedWork W1974913431 @default.
- W4386481289 hasRelatedWork W2038778299 @default.
- W4386481289 hasRelatedWork W2141892377 @default.
- W4386481289 hasRelatedWork W2152693475 @default.
- W4386481289 hasRelatedWork W2562699033 @default.
- W4386481289 hasRelatedWork W2921658239 @default.
- W4386481289 hasRelatedWork W3216196901 @default.
- W4386481289 hasRelatedWork W4313367526 @default.
- W4386481289 hasRelatedWork W758328641 @default.
- W4386481289 hasVolume "2" @default.
- W4386481289 isParatext "false" @default.
- W4386481289 isRetracted "false" @default.
- W4386481289 workType "article" @default.