Thermal treatment of plutonium contaminated material (PCM) waste

MRS Advances ◽  
2017 ◽  
Vol 2 (13) ◽  
pp. 735-740
Author(s):  
Luke Boast ◽  
M.C. Stennett ◽  
Neil C. Hyatt
Keyword(s):  
Thermal Treatment ◽  
Long Term Stability ◽  
Treatment Processes ◽  
Matrix Interactions ◽  
Fundamental Understanding ◽  
Treatment Technologies ◽  
Key Drivers ◽  
The Impact

ABSTRACTKey drivers for the application of thermal treatment processes include the reduced volume, improved passive safety, and superior long term stability of the vitrified wasteform products. These advantages have led to a renewed interest in thermally treating various UK ILW streams. To support the increased investment in thermal treatment technologies a fundamental understanding of the processes and the impact of waste inventory needs to be established. The research described in this report aims to provide the evidence necessary to support a major investment in thermal treatment of Plutonium Contaminated Materials (PCM). The report describes the use of laboratory scale waste simulants to develop an understanding of the waste and matrix interactions during thermal treatment of PCM waste. The report includes the thermal treatment process and characterization of the vitrified product.

Enhanced stability of conductive polyacetylene in ladder-like surface-grafted brushes

2016 ◽  
Vol 7 (36) ◽  
pp. 5664-5670 ◽  
Author(s):  
Michał Szuwarzyński ◽  
Karol Wolski ◽  
Szczepan Zapotoczny
Keyword(s):  
Term Stability ◽  
Long Term Stability ◽  
Enhanced Stability

Formation and characterization of polyacetylene-based brushes that exhibit exceptional long term stability in air is presented here.

Separating the impact of oxygen and water on the long-term stability of n-channel perylene diimide thin-film transistors

2015 ◽  
Vol 26 ◽  
pp. 340-344 ◽  
Author(s):  
Ute Zschieschang ◽  
Konstantin Amsharov ◽  
Martin Jansen ◽  
Klaus Kern ◽  
Hagen Klauk ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Film Transistors ◽  
Perylene Diimide ◽  
Term Stability ◽  
Long Term Stability ◽  
The Impact

Geochemical Behaviour of Uranium in Sedimentary Formations: Insights From a Natural Analogue Study

2009 ◽  
Author(s):  
Ulrich Noseck ◽  
Vaclava Havlova ◽  
Juhani Suksi ◽  
Thomas Brasser ◽  
Radek Cervinka
Keyword(s):  
Current Knowledge ◽  
Natural Analogue ◽  
Near Surface ◽  
Co2 Partial Pressure ◽  
Long Term Stability ◽  
Reducing Conditions ◽  
Phosphate Mineral ◽  
Sedimentary System ◽  
The Impact

Groundwater data from the natural analogue site Ruprechtov have been evaluated with special emphasis on the uranium behaviour in the so-called uranium-rich clay/lignite horizon. In this horizon in-situ Eh-values in the range of −160 to −280 mV seem to be determined by the SO42−/HS− couple. Under these conditions U(IV) is expected to be the preferential redox state in solution. However, on-site measurements in groundwater from the clay/lignite horizon show only a fraction of about 20% occurring in the reduced state U(IV). Thermodynamic calculations reveal that the high CO2 partial pressure in the clay/lignite horizon can stabilise hexavalent uranium, which explains the occurrence of U(VI). The calculations also indicate that the low uranium concentrations in the range between 0.2 and 2.1μg/l are controlled by amorphous UO2 and/or the U(IV) phosphate mineral ningyoite. This confirms the findings from previous work that the uranium (IV) mineral phases are long-term stable under the reducing conditions in the clay/lignite horizon without any signatures for uranium mobilisation. It supports the current knowledge of the geological development of the site and is also another important indication for the long-term stability of the sedimentary system itself, namely of the reducing geochemical conditions in the near-surface (30m to 60 m deep) clay/lignite horizon. Further work with respect to the impact of changes in redox conditions on the uranium speciation is on the way.

scholarly journals The Impact of Advanced Treatment Technologies on the Energy Use in Satellite Water Reuse Plants

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 366 ◽  
Author(s):  
Jonathan R. Bailey ◽  
Sajjad Ahmad ◽  
Jacimaria R. Batista
Keyword(s):  
Energy Consumption ◽  
Water Reuse ◽  
Energy Use ◽  
Additional Treatment ◽  
Advanced Treatment ◽  
World Population ◽  
Water Reclamation ◽  
Treatment Processes ◽  
Treatment Technologies ◽  
The Impact

With an ever-increasing world population and the resulting increase in industrialization and agricultural practices, depletion of one of the world’s most important natural resources, water, is inevitable. Water reclamation and reuse is the key to protecting this natural resource. Water reclamation using smaller decentralized wastewater treatment plants, known as satellite water reuse plants (WRP), has become popular in the last decade. Reuse plants have stricter standards for effluent quality and require a smaller land footprint (i.e., real estate area). They also require additional treatment processes and advanced treatment technologies. This greatly increases the energy consumption of an already energy intensive process, accentuating even more the nexus between energy use and wastewater processing. With growing concerns over the use of nonrenewable energy sources and resulting greenhouse gas (GHG) emissions, WRPs are in need of energy evaluations. This paper contrasts the energy consumption of both conventional and advanced treatment processes in satellite WRPs. Results of this research provide a means for engineers and wastewater utilities to evaluate unit processes based on energy consumption as well as a foundation for making decisions regarding the sustainability of using advanced treatment technologies at reuse facilities.

scholarly journals Biochemical Characterization of Phenylacetaldehyde Dehydrogenases from Styrene-degrading Soil Bacteria

2020 ◽  
Author(s):  
Juliane Zimmerling ◽  
Michel Oelschlägel ◽  
Carolin Großmann ◽  
Matthias Voitel ◽  
Michael Schlömann ◽  
...  
Keyword(s):  
Esterase Activity ◽  
Soil Bacteria ◽  
Biochemical Characterization ◽  
Specific Activity ◽  
Aldehyde Dehydrogenases ◽  
Long Term Stability ◽  
Almost All ◽  
Different Characteristics

Abstract Four phenylacetaldehyde dehydrogenases (designated as FeaB or StyD) originating from styrene-degrading soil bacteria were biochemically investigated. In this study, we focused on the Michaelis-Menten kinetics towards the presumed native substrate phenylacetaldehyde and the obviously preferred co-substrate NAD+. Furthermore, the substrate specificity on four substituted phenylacetaldehydes and the co-substrate preference were studied. Moreover, these enzymes were characterized with respect to their temperature as well as long-term stability. Since aldehyde dehydrogenases are known to show often dehydrogenase as well as esterase activity, we tested this capacity, too. Almost all results showed clearly different characteristics between the FeaB and StyD enzymes. Furthermore, FeaB from Sphingopyxis fribergensis Kp5.2 turned out to be the most active enzyme with an apparent specific activity of 17.8 ± 2.1 U mg-1. Compared with that, both StyDs showed only activities less than 0.2 U mg-1 except the overwhelming esterase activity of StyD-CWB2 (1.4 ± 0.1 U mg-1). The clustering of both FeaB and StyD enzymes with respect to their characteristics could also be mirrored in the phylogenetic analysis of twelve dehydrogenases originating from different soil bacteria.

Comparative and integrative environmental assessment of advanced wastewater treatment processes based on an average removal of pharmaceuticals

2013 ◽  
Vol 67 (2) ◽  
pp. 387-394 ◽  
Author(s):  
Elorri Igos ◽  
Enrico Benetto ◽  
Silvia Venditti ◽  
Christian Köhler ◽  
Alex Cornelissen
Keyword(s):  
Removal Rate ◽  
Treatment Plant ◽  
Post Treatment ◽  
Activated Carbon Adsorption ◽  
Treatment Processes ◽  
Carbon Adsorption ◽  
Decentralized Treatment ◽  
Advanced Technologies ◽  
Treatment Technologies

Pharmaceuticals are normally barely removed by conventional wastewater treatments. Advanced technologies as a post-treatment, could prevent these pollutants reaching the environment and could be included in a centralized treatment plant or, alternatively, at the primary point source, e.g. hospitals. In this study, the environmental impacts of different options, as a function of several advanced treatments as well as the centralized/decentralized implementation options, have been evaluated using Life Cycle Assessment (LCA) methodology. In previous publications, the characterization of the toxicity of pharmaceuticals within LCA suffers from high uncertainties. In our study, LCA was therefore only used to quantify the generated impacts (electricity, chemicals, etc.) of different treatment scenarios. These impacts are then weighted by the average removal rate of pharmaceuticals using a new Eco-efficiency Indicator EFI. This new way of comparing the scenarios shows significant advantages of upgrading a centralized plant with ozonation as the post-treatment. The decentralized treatment option reveals no significant improvement on the avoided environmental impact, due to the comparatively small pollutant load coming from the hospital and the uncertainties in the average removal of the decentralized scenarios. When comparing the post-treatment technologies, UV radiation has a lower performance than both ozonation and activated carbon adsorption.

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