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The continued electrification of society and the related growing demand for rechargeable batteries require in turn the elaboration of efficient and sustainable recycling strategies for their recovery and valorization. An important separation relevant to nickel metal hydride (NiMH) and lithium-ion battery recycling is the intertransition element separation between Ni(II), Co(II), and Mn(II). In this work, a fully aqueous process for the recovery of Mn(II) and Co(II) from concentrated Ni(II) effluents typical of NiMH battery leachate is disclosed consuming only Na2CO3. In the first instance, Mn is selectively precipitated as Mn(IV) by oxidation using ozone as an oxidant, resulting in a significant enrichment of Mn in the precipitate relative to its original solution concentration. Second, a thermo- and acid-responsive aqueous biphasic system (ABS) based on the ionic liquid (IL) tributyltetradecylphosphonium chloride ([P44414]Cl) and NiCl2 was used to recover Co(II). By using the high NiCl2 content found in NiMH leachates both as the ABS phase former and salting-out agent, no additional salt is required. Through careful manipulation of the Co(II) to Ni(II) and the IL to Co(II) molar ratios, an effective and selective separation of Co(II) from Ni(II) was achieved. Finally, Co(II) is precipitated from the IL-rich phase and the IL is regenerated in one step by the addition of Na2CO3 to induce a new phase separation. published

The factors influencing metal partition in acidic aqueous biphasic systems (AcABS) containing phosphonium-based ILs are still poorly explored. To assess their influence the effect of the IL counter anion, acid and its concentration, and temperature, were systematically evaluated on the extraction of four transition metals (Cu(II), Co(II), Ni(II), and Mn(II)) and the lanthanide Ce(IV). The AcABS based on HCl showed good ability to extract Co(II) and Cu(II) to the IL-rich phase. In contrast, AcABS based on H2SO4 showed overall poor metal extraction, except for the [P44414]Cl + H2SO4 + H2O system. The latter showed good Cu(II) affinity at higher H2SO4 concentrations. The biphasic systems based on HNO3 were unable to extract transition metals to the IL-rich phase, with chloride from [P444414]Cl hampering Ce(IV) extraction. The [P44414]Cl + H2SO4 + H2O system was further optimized by adding small amounts of HCl to the system. The extraction efficiency of the metals is linked to the charge density of the metal-complex and its inherent free energy of hydration, the anion/water molar ratio changes induced by temperature and ionic strength, and the dissociation degree of the acid. By using these parameters it was possible to tune the selectivity and efficiency of the AcABS. Moreover, metal extraction was found to preferentially occur via an ion-pair mechanism, with split anion extraction taking place in AcABS containing different anions. published

Hydrogen is one of the most promising energy carriers. Currently, the most used technology to produce electricity from hydrogen, particularly for green mobility, is the technology based on the use of Proton Exchange Membrane Fuel Cells (PEMFC). Platinum, pure or alloyed with another element, remains essential in the design of efficient catalysts either for anode or cathode catalytic layer in PEMFC. This metal is rare and expensive hence recycling it becomes an important issue for the hydrogen sector development. Chemical ways to recover platinum from PEMFC have been already studied 1-2 based on Pt leaching using either a mix of HCl/HNO3 or HCl/H2O2. In our project, we investigate an electrochemical process to leach platinum contained in aged Pt based catalysts to further resynthesize catalysts from the recovered Pt salts. The electrodissolution of platinum becomes significant with the oxidation of the metal (around 1.1 V vs RHE) but particularly when the oxidized platinum is reduced (around 0.7 V vs RHE) 3. Moreover, the dissolution is enhanced when a complexing agent as chloride anion is introduced 4. The idea of our process is to study the impact of different protocol of steps between high potential (to oxidize platinum) and low potential (to reduce platinum oxide). The improvement of the process is linked to the upper and lower potential values, the number of steps and the nature of the electrolyte and the complexing agent. Our main parameter to monitor the dissolution is the changes in electrochemical real surface area (ECSA) associated to transmission electron microscopy (TEM) images of the catalyst at different stages of the protocol as illustrated in Figure 1. In terms of methodology a model study on fresh commercial Pt/C catalyst has been first performed to determinate the optimal conditions of Pt dissolution followed by the application of the protocol on membrane electrode assemblies (MEA) aged in real conditions. 1 L. Duclos, L. Svecova, V. Laforest, G. Mandil, et P.-X. Thivel, « Process development and optimization for platinum recovery from PEM fuel cell catalyst », Hydrometallurgy, vol. 160, p. 79-89, mars 2016, doi: 10.1016/j.hydromet.2015.12.013. 2 L. Duclos, M. Lupsea, G. Mandil, L. Svecova, P.-X. Thivel, et V. Laforest, « Environmental assessment of proton exchange membrane fuel cell platinum catalyst recycling », J. Clean. Prod., vol. 142, p. 2618-2628, janv. 2017, doi: 10.1016/j.jclepro.2016.10.197. 3 S. Cherevko, A. R. Zeradjanin, G. P. Keeley, et K. J. J. Mayrhofer, « A Comparative Study on Gold and Platinum Dissolution in Acidic and Alkaline Media », J. Electrochem. Soc., vol. 161, n° 12, p. H822-H830, 2014, doi: 10.1149/2.0881412jes. 4 S. Geiger, S. Cherevko, et K. J. J. Mayrhofer, « Dissolution of Platinum in Presence of Chloride Traces », Electrochimica Acta, vol. 179, p. 24-31, oct. 2015, doi: 10.1016/j.electacta.2015.03.059. Figure 1

International audience; This paper discusses the feasibility of tantalum electrodeposition carried out under potential control from 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide [BMPyr][TFSI] room temperature ionic liquid electrolyte containing tantalum pentafluoride (TaF5). The influence of electrode nature, electrolyte temperature and electrolysis duration on the morphology, the adherence, the thickness and the crystalline properties of tantalum deposits is reported. The obtained tantalum deposits are analyzed by SEM, XRD, Raman spectroscopy and XPS surface analytical techniques. Pulsed potential electrodeposition is investigated in order to enhance deposit properties. Post electrodeposition thermal treatments are also reported.

An acidic aqueous biphasic system (AcABS) presenting a desired and reversible phase transition with HNO3 concentration and temperature was developed herein as an integrated platform for metal separation. The simple, economical, and fully incinerable (C,H,O,N) AcABS composed of tetrabutylammonium nitrate ([N4444][NO3])+HNO3 +H2O was characterized and presented an excellent selectivity towards CeIV against other rare earth elements and transition metals from both synthetic solutions and nickel metal hydride (NiMH) battery leachates. The acid-driven self-assembly of AcABS bridges the gap between traditional ABS and liquid-liquid extraction whilst retaining their advantageous qualities, including compatibility with highly acidic solutions, water as the primary system component, the avoidance of organic diluents, rapid mass transfer, and the potential integration of the leaching and separation steps. published

An acidic aqueous biphasic system (AcABS) presenting a desired and reversible phase transition with HNO

Rechargeable Li-ion batteries have been developed and marketed over the past 30 years and are used today in different fields like electric vehicles, portable electronics, etc. In a few years, the development of this technology has been exponential, and it has quickly imposed on the energy storage market. However, it is important to note that this technology is very dependent on metals (Co, Ni, Cu, Al, Li ...). These metals are rare, expensive and non-renewable. In addition, they are unevenly distributed in the earth's crust and their production is often very polluting. Thus, the massive use of this technology is creating an imbalance between the needs for metals and the existing primary resources, leading irrevocably to environmental and economic problems.Recycling this waste is therefore essential to both limit the overexploitation of primary metal resources and reduce their ecological impact. In terms of batteries recycling, two main families of processes can be distinguished. The first, known as pyrometallurgy, is based on the high-temperature treatment of waste. In contrast, hydrometallurgical processes are processes with significantly lower energy costs, as these processes are carried out at near ambient temperatures. The principle is to dissolve metals in their ionic form. Toxic acids (and their mixtures) are very often used, but other methods are possible (bases, complexing agents, oxidants). Once in solution, the metals can be recovered in the form of salts, hydroxides or in their metallic form by conventional chemical processes (precipitation, crystallization, etc.) or electrochemical processes (electro-deposition). Several separation / purification steps are sometimes necessary. Relatively few studies have looked at closed-loop recycling, i.e. the resynthesis and reuse of recycled materials in batteries. Thus, the objective of this project is to test the feasibility of closed-loop recycling of cathode materials from Li-ion batteries based on the use of innovative and less toxic recycling routes, and to verify the electrochemical performance of recycled materials at the end of the recycling process. To build this green cycle, the present study has been carried out using both model cathode materials (LCO, NMC) and real cathodes from spent drone batteries, that have been discharged, opened and dismantled in a glove box. All materials have, of course, been characterised (X-ray diffraction, SEM) and the present metals content has been quantified (wet digestion followed by AAS analyses) in order to be able to establish reliable material balances at the end of the recycling process. The developed closed-loop recycling process was composed of three subsequent steps: 1) The cathode materials recovered have been leached in a deep eutectic solvent medium (DES) composed of ethylene glycol – choline chloride mixture, replacing the concentrated acids traditionally used. DES is a new class of green solvents, that is, non-harmful to human health and the environment compared to conventional organic solvents. They consist of a mixture of products (solids) which, at a given ratio, become liquid (eutectic), and which have the combined properties of the different constituents of the mixture. 2) Synthesis of recycling active material from the DES media by precipitation and calcination. 3) Assembly of button cells, followed by electrochemical tests and batteries post-mortem analyses (X-ray diffraction, SEM) have been carried-out at the last step. Composite electrodes made of recycled active materials, polymer binder and carbon have been formulated and assembled into button cells with a Li counter-electrode and a conventional separator (e.g. Celgard impregnated with liquid electrolyte). The prepared batteries were then recycled by electrochemical methods coupled with impedance measurements. The aging of the cells was carried out through one hundred charge / discharge cycles and a specified «fast charging» test developed in our laboratory, allowing to calculate the lithium diffusion coefficient in the cathode material. The results have shown that the recycling of metals has been successfully carried out using a deep eutectic solvent (DES), in a closed-loop manner. The leaching protocol have been optimized at the optimum conditions: ChCl: EG (1:2) with 0.8 mol.L-1 of HCl, with a ratio(wt.) S/L of 1/50, heated to 87.5 °C, for 2 h. After being completely dissolved, the metals have been then recovered from the DES by precipitation, calcined and reused as active materials. Using this method, the DES solvent has also been recovered and reused in a closed-loop without suffering any damage. This work has also shown that the recovered battery materials can be reused into the battery manufacturing cycle without changing their electrochemical performance. Indeed, this process allowed to obtain a homogeneous powder with a morphology similar to the initial materials (particle size -1). Figure 1

Pozadí výzkumu: Článek se zabývá dobrovolnictvím. Vztah mezi školní a dobrovolnickou orientací je srovnáván mezi respondenty připravujícími se na budoucí trh práce, tj. Studenty středních a vysokých škol různých oborů, kteří studují v České republice. Studenti mohou být motivováni získáváním zkušeností v týmové spolupráci při řešení společného cíle, jako je jeden typ motivátoru. Jsou dobrovolníci a potenciální dobrovolníci ochotni věnovat svůj čas projektům stejným způsobem, ať už mají nebo nemají zkušenosti s dobrovolnictvím? Účel článku: Účelem je najít souvislost mezi věkem respondentů, jejich zkušenostmi s dobrovolnictvím a časem, který jsou ochotni dobrovolnictví věnovat. Metody: Metodou je kvantitativní studium odpovědí studentů středních a vysokých škol. Kvantitativní studie používá test chí kvadrát. Výsledkem kvantitativního zpracování dotazníkového šetření je odpověď na otázku, zda existuje souvislost mezi věkem respondentů, jejich zkušenostmi s dobrovolnictvím a časem, který jsou ochotni dobrovolnictví věnovat. Zjištění a přidaná hodnota: Výsledkem jsou rozdíly a souvislosti mezi věkem dobrovolníků, jejich zkušenostmi s dobrovolnictvím a ochotou být dobrovolníkem na delší či kratší dobu. Výsledek průzkumu přináší manažerům výhody při náboru dobrovolníků a nelze popřít, že se ochota dobrovolníků věnovat svůj čas dobrovolnictví změní, jakmile získají zkušenosti. Burial mounds are considered as a typical monument of the Early and Middle Bronze Age in southern Bohemia, representing the only form of graves within BA–BC2 in the area. Although the existing literature has stated hundreds of burial mounds at dozens of cemeteries, after a critical review, only 19 burial mounds from 10 sites can be assigned to the Early Bronze Age, and further 73 burial mounds from 29 sites represent the Middle Bronze Age. Most of the mounds are polycultural, however, burying attributable to both the monitored periods can be unequivocally proven only within four mounds. Even so, an occasional continuity can be taken into account when thinking about using these funeral places.

International audience; 18 Starting from a real Proton Exchange Membrane Fuel Cell (PEMFC) leachate, separation of the 19 strategic metals platinum(IV) and cobalt(II) was carried out using two distinct strategies applying ionic 20 liquids (ILs), either via solvent extraction (SX) or acidic aqueous biphasic system (AcABS). The 21 versatility of ILs and their ability to provide original solutions to common issues in the field of used 22 device recycling is illustrated, with both approaches critically compared. The highly hydrophobic 23 tetradecylpyridinium bis(trifluoromethanesulfonyl)imide ([C 14 pyr][NTf 2 ]) was synthesized and applied 24 to the separation of Pt/Co. This solvent was able to selectively extract over 98% of Pt(IV) from the 25 PEMFC leachate in one step while leaving Co(II) in the aqueous phase and exhibited the highest 26 reported partition of Pt(IV) in a [NTf 2 ]-based IL. In a second approach, the AcABS based on the fully 27 water-miscible tributyltetradecylphosphonium chloride ([P 44414 ]Cl), HCl and water, is compatible with 28 the concentrated nature of the leachate and extracts both platinum(IV) and cobalt(II) quantitatively. In 29 a second stage, a selective precipitation step enabled the recovery of platinum(IV) in the form of an 30 organometallic complex whilst leaving the co-extracted cobalt(II) in solution. This work represents the 31 2 first utilization of an AcABS for the recycling of a real waste technological object. These two different 32 types of ILs in both cases resulted in an efficient separation of Pt(IV) from Co(II), using two very 33 different pathways. The merit and transferability of each approach is critically compared, and 34 suggestions are made as to the suitable condition range for each technique. 35 36

International audience; In this work, the important role played by metal ions such as Fe(II/III), Cr(III) and Ni(II) in the formation and binodal behaviour of aqueous biphasic systems (ABS) composed of HCl and the ionic liquid, [P44414]Cl, or the polymer, PEG-600, is investigated. The concentration of metal ions used in this work exceeds several g/L for an industrial foreseen application. Experiments have also been carried out by varying the concentration of metal ions at different temperatures. Fe exhibits a totally different behaviour compared to Ni and Cr. In particular, the binodal curves in presence of the ionic liquid are far from the classical curves found in the literature, displaying an onion-shape form, while for Ni and Cr, the curves follow the classical trend. When any of the three metal ions is mixed with the polymer and HCl medium, only Fe(III) induces a biphasic system. Insights into the chemical driving forces at work are discussed.Introduction In recent years, neutral Aqueous Biphasic Systems (ABS), composed of different polymer-polymer, polymer-salt or salt-salt combinations, plus water as the main protagonist, have been taken into consideration to selectively extract metal ions. In particular, the use of the [P44414]Cl (tri-butyl tetradecyl phosphonium chloride) ionic liquid (IL) or of the polyethene glycol (PEG) polymer for metal extraction has already been the subject of several papers. 1-6 The use of these compounds, more appropriately called biphasic inducers in these classical ABS, helps to make the process eco-sustainable. The [P44414]Cl hydrophilic ionic liquid (i) is less toxic than the respective hydrophobic IL 7 , (ii) can be used in much lower quantities than organic volatile solvents and (iii) the extraction kinetics is favored by its low viscosity. In regards to the PEG, this is an inexpensive, nontoxic, non-flammable compound which is commercially available in very large quantities. These systems are intrinsically much eco-friendlier than the classical liquid-liquid systems where organic solvents are used as main components and could thus be favorably considered by the industry. However, in order to comply with any industrial demand, extraction should proceed from highly loaded wastes, which is currently very rarely the case in the literature. Furthermore, most industrial wastes are highly acidic, which is not compatible with the most classical ABSs. Therefore, in the first step, we took advantage of the recently described Acidic Aqueous Biphasic Systems (AcABS) 8 loaded with very high concentrations of either Cr, Ni or Fe to perform fundamental studies in view of potential industrial applications. In this work, aqueous biphasic systems (ABS) are formed from solutions containing a single metal element, HCl as the acid, and using either [P44414]Cl or PEG as biphasic inducer. We focused on the influence of the metal, in particular on the contribution coming from the type of metal used and on its concentration. Furthermore, the influence of temperature has been taken into consideration for industrial needs. Finally, we reviewed past literature which proposed some possible explanations and we discussed these under the light of our experimental results. Experimental Section Chemicals Polyethene glycol with an average molecular weight of 600 (abbreviated as PEG-600) was acquired from Acros Organics. The ionic liquid tributyl tetradecyl phosphonium chloride, [P44414]Cl, was acquired from Interchim (Montluçon, France). The declared purity was > 95%. Some basic physicochemical properties of PEG-600 are reported in the supplementary materials. The hydrochloric acid, HCl, (37 wt% = 12 mol/L, in water) was acquired from Sigma-Aldrich. The following hydrated salts have been used: NiCl2.6H2O pure at 98% acquired from Rectapur, CrCl3.6H2O pure at 98% acquired from Fluka, FeCl2.4H2O pure at 98% and FeCl3.6H2O pure at 99% were acquired from Merck. All the chemicals were used without further purification. The water used in all experiments was passed through a Milli-Q apparatus purification system commercialized by Merck (18MΩ). AAS (Atomic Absorption Spectroscopy) single element standard solutions (1000 mg/L) were acquired from Perkin Elmer for Cr and from Chem-Lab for Fe and Ni. Sample preparation

In this work, the important role played by metal ions such as Fe(ii/iii), Cr(iii) and Ni(ii) in the formation and binodal behaviour of aqueous biphasic systems (ABS) composed of HCl and the ionic liquid, [P44414]Cl, or the polymer, PEG-600, is investigated. The concentration of metal ions used in this work exceeds several g L-1 for an industrial foreseen application. Experiments have also been carried out by varying the concentration of metal ions at different temperatures. Fe exhibits a totally different behaviour compared to Ni and Cr. In particular, the binodal curves in the presence of the ionic liquid are far from the classical curves found in the literature, displaying an onion-shape form, while for Ni and Cr, the curves follow the classical trend. When any of the three metal ions is mixed with the polymer and HCl medium, only Fe(iii) induces a biphasic system. Insights into the chemical driving forces at work are discussed.

Ionic-liquid-based aqueous biphasic systems (IL-based ABS) have demonstrated exceptional performance in bioseparation processes. However, IL-based ABS are of limited interest for metal extraction as most metals are not stable in their neutral or alkaline pH conditions. In the quest for better extraction systems for metals, the development of IL-based ABS with highly acidic solutions (AcABS), induced by the mixture of a hydrophilic IL ([P44414]Cl), a mineral acid (HCl, HNO3 or H2SO4) and water, opens new possibilities. A comprehensive investigation of fundamental aspects of IL-based AcABS was performed, including the temperature dependence of the phase diagrams, tie-lines and ion exchange behavior, evidencing the unique characteristics of these new systems. In particular, the favorable biphasic formation with an increase in temperature showcases the lower critical solution temperature (LCST) behavior of the phosphonium-based IL and opens many possibilities for AcABS application by creating stimuli responsive systems. The anion exchange identified highlights the IL-based AcABS complexity that renders the analytical characterization of the phases mandatory, instead of the traditional method coupling an empirical fit of the binodal with the lever-arm rule. Through judicious selection of the inorganic acid, different extraction systems can be obtained by tuning the degree of anion-exchange, underlining the versatility of the proposed AcABS system.

International audience; This study is focused on the development of environmentally friendly recycling method for selective recovery in a closed loop manner of Co and Pt from Pt3Co/C catalyst used as the PEMFC cathode. Pt and Co selective separation was carried out using two different hydrometallurgical alternatives based either on ion exchange resin or solvent extraction. The recycling process was optimized in order to maximize the platinum recovery yield, which reached 83% and 77% of the Pt initially present in the MEA using respectively solvent extraction or ion exchange resin separation alternatives. The recovered platinum alkaline solutions have been further used for Pt/C particles synthesis via a modified polyol method and it was shown that although the resin alternative resulted in slightly lower recovery yield, the catalyst prepared via this alternative satisfied morphological and electrochemical properties for the oxygen reduction reaction (ORR) by performing similarly to a commercial state-of-art Pt/C catalyst. The feasibility of closed loop Pt/C catalyst recycling was thus proven. The environmental impacts of the two recycling alternatives have been compared using life cycle assessment methodology (LCA) and similar impacts have been found for both alternatives from the point of view of the entire MEA life cycle. The ion exchange resin alternative has thus been selected as the most appropriate one.

Almost 500 municipal solid waste incineration plants in the EU, Norway and Switzerland generate about 17.6 Mt/a of incinerator bottom ash (IBA). IBA contains minerals and metals. Metals are mostly separated and sold to the scrap market and minerals are either disposed of in landfills or utilised in the construction sector. Since there is no uniform regulation for IBA utilisation at EU level, countries developed own rules with varying requirements for utilisation. As a result from a cooperation network between European experts an up-to-date overview of documents regulating IBA utilisation is presented. Furthermore, this work highlights the different requirements that have to be considered. Overall, 51 different parameters for the total content and 36 different parameters for the emission by leaching are defined. An analysis of the defined parameter reveals that leaching parameters are significantly more to be considered compared to total content parameters. In order to assess the leaching behaviour nine different leaching tests, including batch tests, up-flow percolation tests and one diffusion test (monolithic materials) are in place. A further discussion of leaching parameters showed that certain countries took over limit values initially defined for landfills for inert waste and adopted them for IBA utilisation. The overall utilisation rate of IBA in construction works is approximately 54 wt%. It is revealed that the rate of utilisation does not necessarily depend on how well regulated IBA utilisation is, but rather seems to be a result of political commitment for IBA recycling and economically interesting circumstances. Export Date: 20 December 2019 ispartof: Waste Management vol:102 pages:868-883 ispartof: location:United States status: published

This work addresses the surface characterization of an organic salt based on a piperidinium cation and a halide anion, similar to a first generation ionic liquid, using the Inverse Gas Chromatography (IGC) technique. IGC was employed in order to assess the dispersive surface energy and the acid/base character of 1-butyl-1-ethylpiperidinium bromide, [C2C4PIP]Br at a temperature range (313.15–343.15 K) well below its melting point, where the retention mechanism is governed by the surface adsorption of the probes. This type of characterization was possible due to the high melting point of [C2C4PIP]Br, namely 413.15 K. The dispersive component of the surface energy was estimated with the aid of the Schultz method and the Dorris-Gray method. Results obtained using the first method were higher than the ones obtained by the latter. The discrepancy between the two methods was found to increase with the increase of temperature. The acid/base characterization was implemented by using the Flour and Papirer approach as well as the Brookman and Sawyer method. The acidity and basicity constants of the surface of [C2C4PIP]Br revealed that it is amphoteric with a predominantly basic character.

Příspěvek se zabývá tématem dobrovolnictví. Klíčovou úlohou při řízení dobrovolnické práce je stimulovat je k podpoře vnitřní motivace. Vedení dobrovolníků musí znát potřeby dobrovolníků pro lepší nastavení komunikace a podmínek spolupráce. Tento článek hodnotí hypotézu: „Lidé, kteří by chtěli být dobrovolníky, mají jinou motivační strukturu než lidé, kteří by nechtěli být dobrovolníkem.“ Cíl je podporován zaměřením na motivaci dobrovolníků, kteří nemohou být stimulováni finanční hodnotou. Dobrovolnictví proměňuje pořadí hierarchie potřeb dobrovolníků v jejich projektech. Příspěvek je založen na kvalitativním výzkumu jako dotazníkovém šetření. Lze potvrdit hypotézu, že se naše koncentrované skupiny liší v hierarchii potřeb, ale je třeba si uvědomit, že různé velikosti skupin respondentů a faktorů (věk, osobní zkušenosti, vrozené předpoklady, osobní typy atd.) mohou vést k různým výsledkům. The paper discusses the topic of volunteering. A key role in managing volunteer work is to stimulate them to support internal motivation. The management of volunteers needs to know volunteers needs for better setting of communications and conditions of the cooperation. This paper assesses the hypothesis: “People who would like to be a volunteer have different motivation structure than people who would not like to be”. The aim is supported by focusing on the motivation of volunteers who can not be stimulated by financial value. The nature volunteering causes the change in the hierarchy of volunteers needs in their projects. The paper is based on qualitative research as a questionnaire survey. The hypothesis that our concentrated groups have a different focus in the hierarchy of needs could be confirm, but it is necessary note that different sizes of respondent groups and factors (age, personal experiences, innate assumptions, personal types etc.) could lead to different results.

International audience; In this paper, we report and discuss the reduction mechanism of pentavalent tantalum salt (TaF5) in a room temperature ionic liquid (RTIL) by coupling two complementary electrochemical techniques: the cyclic voltammetry and the electrochemical quartz crystal microbalance (EQCM). The experiments were performed in the hydrophobic 1-butyl-3-methyl pyrrolidinium bis(trifluoromethylsulfonyl) imide ([BMPyr][TFSI]) RTIL used both as a solvent and as an electrolyte. Four different reduction peaks are present in the obtained voltammogram in the range from 0 V (vs Pt-Fc/Fc+) to −3.5 V (vs Pt-Fc/Fc+). The existence of the first reduction peak depends mainly on the nature of the substrate of the working electrode and is therefore not related to the reduction of the tantalum salt. The second reduction peak is ascribed to the direct tantalum salt reduction to its metallic state. During this reduction, free fluoride ions are produced in the electrolyte in the vicinity of the electrode surface. These ions can then react with diffusing TaF5 to form TaF5+x−x complexes and thus the reduction peaks occurring at lower potential are referred to the reduction of such complexes. This hypothesis was confirmed by addition of LiF in the electrolyte.

International audience; The present work deals with the modeling of selenium oxyanion (selenite/selenate) retention in TiO2 rutile porous media. A set of chemical interactions was elaborated from spectroscopic measurements and adsorption experiments in batch and column reactors, and a model of transient transport of the selenium species through laboratory column was developed. The adsorption model considered that both forms of selenium (Se) compete for the same sorption sites, hydroxyl groups, allowing taking into account a competitive adsorption. Stoichiometry and equilibrium constants of adsorption reactions were determined on the basis of spectrometric measurement and adsorption isotherm curve fitting. This approach led to a model of Sips type isotherm including a pH-dependence. It offers an excellent fitting compared to the classical Langmuir equation and provides a unique set of parameters for both oxyanions. IMPACT code and associated modeling method were then used to couple transport and chemical reactions. The obtained numerical results showed a reasonable prediction of the shape and the time location of selenium oxyanions and pH breakthrough curves.

International audience; Since the Manhattan Project in the early 1940s, the separation and recovery of metals from solution by solvent extraction has gained a lot of attention and it is nowadays, together with precipitation and ion exchange, one of the three main separation techniques for metals recovery, largely used in mining, nuclear and metallurgical industries as well as in waste water treatment. For years, in the solvent extraction field, the primary objective was to find the "good" solvent-extractant couple in order to develop an efficient separation system for a given metal. This was mainly driven by the fact that the metal resources were rather stable (mainly the richer ores of more or less defined composition). Once this couple was identified , the optimum extraction parameters were searched for. Tremendous efforts have been successfully applied in the adjustment of the extracting phase characteristics, mainly based on the extracting agent/diluent couple, possibly complemented by a phase modifier to avoid third phase formation, a synergist, etc. Considering the rather limited number of suitable organic solvents, most of the work has dealt with fine-tuning of the extracting agent's chemical structure. Based on the latter consideration, solvent extraction systems are traditionally divided into cation exchangers, anion exchangers and neutral extractants. This is related to the extraction mechanism that thus seems mainly, if not entirely, governed by the extracting phase composition. Our world is a changing one and the increase in demand for metals has induced interest in a broader variety of starting materials, where waste electronic equipment (WEE) or ores of poorer grade are now considered as possible starting materials for metal extraction , separation and recovery. Furthermore, environmental regulations have strengthened

Official development assistance provides an immense flow of financial funding to educational nonprofit organizations (NPOs). This source of funding faces criticism because of the unintended indirect effects it has in lowering the relative level of local NPOs&rsquo, capacities. Our contribution addresses NPOs&rsquo, financial capacities in an OECD country that receives a vast inflow of EU funding, namely the Czech Republic. To answer the research question on what impact the external financial assistance has on capacities in NPOs, we applied propensity score matching to a sample consisting of 633 educational NPOs covering the years 2006&ndash, 2013. EU-funded NPOs report higher levels of real revenues, but not real assets, than non-funded NPOs. The EU funding helps in the short-term to improve NPOs&rsquo, budgets, but not to increase assets.

International audience; A proton exchange membrane (PEM) fuel cell, an alternative to combustion processes that consume fossil resources, is used to convert energy stored in the form of hydrogen into electricity. The membrane-electrode assembly (MEA), the core of this system, contains platinum, a noble metal, which is a limited resource. This paper presents an environmental assessment of a recycling process for the platinum catalyst contained in the MEA of a PEM fuel cell. During this study, four hydrometallurgical platinum recovery processes from Pt/C particles have been developed at the laboratory scale. The considered process alternatives are composed of the four following steps: leaching, separation, precipitation and filtration. Approximately 76% of the platinum can be recovered as [NH4]2PtCl6 salt using the most efficient process alternatives. In this case, platinum leaching is carried out with a mixture of H2O2 and HCl, followed by liquid/liquid platinum extraction and a precipitation step.The environmental assessment was performed using the SimaPro 8 tool coupled with the EcoInvent 3.1 database. The environmental impacts were estimated for a 25 cm2 active area MEA considering the production and end-of-life stages of the MEA life-cycle using the CML-IA baseline V3.02 method. The results show that more than half of the main impacts of the MEA life-cycle can be avoided for four relevant impact categories if platinum is recovered in the end-of-life of the product.

International audience; This paper presents the development of an efficient hydrometallurgical recovery process of platinum from Pt catalyst of PEMFC electrodes at laboratory scale, whereby leaching, Pt separation, precipitation and filtration steps were combined in order to optimize the recovery process. The efficiencies of two different leaching agents (H2O2/HCl and HNO3/HCl) and two different separation methods (liquid–liquid extraction and ion exchange resins) were compared in this study. Finally the platinum was recovered by precipitation as ammonium hexachloroplatinate (NH4)2PtCl6 (a PEMFC catalyst precursor) at the outlet of each process alternative. Thus four different process alternatives were tested and compared.At first the experiments were performed with Pt/C particles and hexachloroplatinic acid in order to study the influence of several experimental parameters on platinum recovery efficiency. Then the real PEMFC catalyst coated membranes (CCMs) were treated according to the optimized leaching/recovery process. Finally, the most efficient process alternative gave a 76% Pt recovery yield from CCMs.

Our previous study has demonstrated that industrial waste biomasses of Penicillium oxalicum var. Armeniaca and Tolypocladium sp., could be used for biosorption of Cd, Pb, Hg and Cr(VI). The objective of the present study was to investigate the biosorption mechanisms, while using FT-IR spectroscopy and SEM technique. SEM microscopic observations (coupled with EDX analysis) confirmed the presence of the target metals on the biosorbents surface. Carboxyl groups were identified by FT-IR spectra analysis on the surface of Tolypocladium sample, while the alkaline treated Penicillium sample was characterized by the presence of amine groups. It was proved that the metal biosorption slightly modified the FT-IR spectra, while the mentioned functional groups were involved in the uptake mechanism (chelation on nitrogen containing groups and ion exchange on carboxyl groups).

Granulated Tolypocladium biomass (industrial waste) was tested as mercury biosorbent in continuous mode (fixed bed column). Supplied material contained approx. 70% of fungal biomass and 30% of inert material (diatomaceous earth). Prior to column experiments, batch sorption was also performed. The results of batch experiments were compared to our previous results obtained for powdered biomass (100% biomass material) and an important drop of sorption capacity was observed. For column experiments, the bed height and flow rate were kept constant and the influence of both initial mercury concentration and bead size was investigated. The Adams Bohart, the Thomas and the Yoon and Nelson models were used for the characterization of breakthrough curves.

Two kinds of waste biomass (Penicillium oxalicum var. Armeniaca, Tolypocladium sp.) used in fermentation industry were submitted to different treatments and were tested as biosorbents of cadmium, lead and mercury. The study was initially focused on the evaluation of the impact of pH on the sorption of selected metals and continued with the sorption isotherms determination. The sorption capacities for the target metals can be ranked according to Hg ≫ Pb > Cd for P. oxalicum sorbent and Hg ≫ Cd > Pb for Tolypocladium sp. sorbent. P. oxalicum shows greater sorption capacities (based on sorption capacities in molar units) than Tolypocladium sp. Maximum sorption capacity as high as 270 mg Hg g−1 (initial pH 5, equilibrium pH close to 6.2) has been obtained for Penicillium derived biosorbent. The Langmuir isotherm equation fits significantly better experimental data than the Freundlich isotherm equation. FT-IR spectra and elemental analysis of the biosorbents have shown significant changes in their composition according to the treatment.

The increase in lithium batteries' (LIBs) demand implies a growing consumption of raw materials. Taking into account this rapid growth, it is necessary, from now on, to think about “life cycle” and sustainability in order to preserve and to sustain our natural resources. Based on a literature review, this chapter presents at first the life cycle assessment methodology applied to LIBs. Especially the key points of the analyzed studies will be emphasized here and some improvements will be proposed. The end-of-life stage is analyzed then and a short summary of existing recycling methods is given. Finally, it will be emphasized that the environmental impact assessment of future LIBs should be done by integrating the entire battery life cycle from resources extraction up to recycling.

International audience; Selenium is a known toxic element released in the environment by anthropogenic activities. The present study is devoted to the aqueous sorption behaviour of selenium oxyanions (selenate and selenite) on a reference oxide surface, namely rutile TiO2. Batch sorption kinetics and isotherms have been studied using different physico-chemical conditions of the solution (changes of pH and ionic strength). The sorption was favoured for both anions in acidic conditions, in agreement with a surface complexation mechanism and CD-MUSIC predictions. Spectroscopic investigations of the sorbed rutile powder were also consistent with such a mechanism. EXAFS spectra confirmed that for selenite anions, an inner-sphere mechanism was the most probable process observed. Dynamic sorption experiments using a column filled with rutile powder also substantiated that a part of the surface complexes follows the inner-sphere mechanism, but also evidenced that an outer-sphere mechanism cannot be excluded, especially for selenate anions.

This paper reports a comparative study of three methods for determining the surface charge and acid–base behavior of a TiO2 rutile material. Electrophoretic mobility measurements were performed using two different batch protocols: (i) a “static” mode that consisted of immersing the rutile powder in aqueous solutions of given pH's and ionic strengths for 10 h, and (ii) a “dynamic” mode that consisted of using an automatic titrator to continuously adjust the solution pH with a contact time of 15 min. The same apparatus (a Nanosizer from Malvern) was used to measure the zeta potential of the particles in both methods. These batch experiments were next compared to the determination of the surface charge of rutile using nonlinear chromatography in column experiments. In that case, the rutile powder was compacted to enable the formation of a proper column bed. Therefore, Raman scattering and X-ray photoelectron spectra were used, as well as other physical information such as specific surface area and morphology of the particles, to verify that the rutile powder and compacted form were identical. The three approaches were then compared and discussed in relation to the acid–base behavior of the rutile material.

International audience; The morphological structure evolutions of polyoctenamer upon photo-ageing have been monitored with the aim of correlating the changes of the microstructure with our previous results concerning chemical and molecular evolutions. The influence of the experimental temperature of photo-oxidation has been investigated with regard to the melting temperature of the different crystalline microphases. A critical point was clearly exhibited (10 h of UV exposure at 35 °C). Before this point the degradation occurs according an oxidative process and takes place only in the amorphous phases. During this period, the molecular structure changes to induce rapid cross-linking. After the critical point, the chemical oxidation results from a photolytic process. The extent of the tridimensional network becomes invariant and imperfect crystalline zones are then affected.

Tantalum is a metal of strategic uses such as in the field ofelectronics and biomedical implants. These fields require thedeposition of thin metallic tantalum films on different substrates.The aim of this thesis is to perform tantalum electrodepositionfrom tantalum salt at room temperature using room temperatureionic liquids as electrolytes. Tantalum electrodeposition isimpossible in aqueous solutions; therefore ionic liquids are thebest choice for this application because of their largeelectrochemical window. Room temperature ionic liquidsaccomplish both the roles of a solvent and an electrolyte. Theirperspectives are encouraging for the electrodeposition ofrefractory metals as tantalum. We have established in this thesisnew knowledge about the physicochemical and transportproperties of the electrolyte formed by tantalum salt TaF5 andthe room temperature ionic liquid [BMPyr][TFSI]. These studiescorrelated with electrochemical analysis, morphology andelemental composition analysis of the layers deposited served usin the understanding of the reduction mechanism of tantalumsalt into its metallic form. An amorphous metallic form oftantalum exists in deeper layers of the deposit in addition toresidues of the ionic liquid trapped in the pores of the layers., Le tantale est un métal à utilisation stratégique notamment dansle domaine de l'électronique et des implants biomédicaux,domaines qui requièrent la réalisation de dépôts de tantale encouches minces. L’objectif de cette thèse est de déposer par voieélectrochimique et à température ambiante du tantale métalliqueà partir d'un sel de tantale solubilisé dans un électrolyte liquideionique qui possède à la fois les propriétés d’un solvant et d’unélectrolyte. Ils ont une fenêtre électrochimique large qui les rendprometteurs pour l’électrodéposition des matériaux réfractairescomme le tantale. Nous avons établis au cours de cette thèse denouvelles connaissances sur les propriétés physico-chimiques etde transport de l’électrolyte formé du sel de tantale TaF5 et duliquide ionique [BMPyr][TFSI]. Ces études corrélées à desanalyses électrochimiques et des analyses de la morphologie etde la composition élémentaire du dépôt ont conduit à proposerun mécanisme de réduction du sel de tantale pentavalent entantale métallique. Du tantale métallique sous une formeamorphe existe dans les couches profondes du dépôtaccompagné de résidus du liquide ionique enfermé dans lespores des couches déposées.