Monitoring water-chemistry evolution in the bentonite buffer using magnets: Effects of corrosion on buffer stability

Bentonite has been chosen as a buffer material by several national nuclear-waste management companies because of its swelling capacity and low water permeability, and because it retards the transport of radionuclides and corrosion products toward the geosphere. The aim of the present study was to develop a magnetic material that has the ability to detect changes in groundwater compositions in an underground nucleardeposit facility through variation in its magnetic properties with time. The present study has investigated the effect of the corrosion of NdFeB magnets on the Na-bentonite buffer under different environmental conditions. Seven different aqueous solutions were used for long-time exposure tests (708C, 5 months) with fragments of NdFeB magnets and powdered Na-bentonite. The corrosion of NdFeB alloy had no detectable effect on the mineralogy of the clay minerals, and any change on the bentonite matrix, measured through X-ray diffraction analysis, was related to the different initial chemistry of the solutions.© 2016 by the authors. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC-BY) license (http://creativecommons.org/licenses/by/4.0/)

Monitoring long-term evolution of engineered barrier systems using magnets:Magnetic response

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SATURN D1.1 - Data Management (main report)

SATURN is motivated by frequent demand and capacity imbalances in the European airspace network. Its traffic redistribution mechanisms will be tested on European-wide scale instances to compare different models and analyse modelling results versus current practice. As there are multiple challenges in collecting and processing the data SATURN’s mechanisms and models require, we herein identify the main sources of such data that will be used by the models and provide numerous detailed examples to explain key concepts and project-developed bespoke capabilities

SATURN D1.2 - Data Management (update report)

Motivated by frequent demand and capacity imbalances in the European airspace network, the SATURN project (‘Strategic Allocation of Traffic Using Redistribution in the Network’) is examining realistic ways to use market-based demand-management mechanisms to redistribute air traffic. Building upon the earlier data management report, this document provides an update of data management activities that run throughout the project

Historical mine pollution and environmental resilience: Biomineralization processes and biogeochemical barriers

Three streams in SW Sardinia were studied to evaluate the transport of metals in the environment, and to characterize the natural processes that lead to decreased metal loads. Here we focus on Zn. Although the metal load varies by 2-3 orders of magnitude, we have observed natural biologically mediated attenuation processes, including uptake by vegetation and biomineralization. In this paper, we review the chemical and physical processes that lead to natural Zn attenuation, and discuss the merits of mimicking those processes when designing remediation schemes

SATURN D3.1 - Pricing mechanisms

Motivated by frequent demand and capacity imbalances in the European airspace network, the SATURN project (‘Strategic Allocation of Traffic Using Redistribution in the Network’) is examining realistic ways to use market-based demand-management mechanisms to redistribute air traffic. Building upon previous deliverables this document presents the set of strategic pricing mechanisms for demand-capacity balancing. Four research avenues were pursued, branching into five centralised and two decentralised pricing mechanisms presented. A comprehensive assessment framework is introduced which will facilitate the demonstration of the validity of designed mechanisms

Natural attenuation can lead to environmental resilience in mine environment

Four streams flowing in the Iglesiente and Arburese mine districts (SW Sardinia, Italy), exploited for zinc (Zn) and lead (Pb) extraction from sulphides and secondary non-sulphide mineralization (calamine ores), have been studied combining investigations from the macroscale (hydrologic tracer techniques) to the microscale (X-ray powder diffraction, scanning electron microscopy, X-ray absorption spectroscopy). In the investigated area, concerns arise from release of metals to water during weathering of ore minerals and mine-waste. Specifically, Zn is observed at extremely high concentrations (10s of mg/L or more) in waters in some of the investigated catchments. The results from synoptic sampling campaigns showed marked differences of Zn loads, from 6.3 kg/day (Rio San Giorgio) to 2000 kg/day (Rio Irvi). Moreover, natural attenuation of metals was found to occur i) through precipitation of Fe compounds (Fe oxy/hydroxides and “green rust”), ii) by means of the authigenic formation of metal sulphides promoted by microbial sulphate reduction, iii) by metal intake in roots and stems of plants (Phragmites australis and Juncus acutus) and by immobilization in the rhizosphere, and iv) by cyanobacterial biomineralization processes that lead to formation of Zn-rich phases (hydrozincite and amorphous Zn-silicate). The biologically mediated natural processes that lead to significant abatement and/or reduction of metal loads, are the response of environmental systems to perturbations caused from mine activities, and can be considered part of the resilience of the system itself. The aim of this study is to understand the effect of these processes on the evolution of the studied systems towards more stable and, likely, resilient conditions, e.g. by limiting metal mobility and favouring the improvement of the overall quality of water. The understanding of how ecosystems adapt and respond to contamination, and which chemical and physical factors control these natural biogeochemical barriers, can help to plan effective remediation actions