Long-term outdoor testing shows that lead release from encapsulated perovskite solar cells is minimal, even after intentional damage, and results in soil lead concentrations well below regulatory thresholds.

The recovery of critical raw materials such as indium (In) and silver (Ag) from end-of-life thin-film photovoltaics is essential for supporting the growing demand for renewable energy technologies. This study evaluates the acid stability of layer-by-layer nanofiltration (LbL-NF) membranes for metal recovery from acidic leachates to identify a sustainable alternative to conventional methods. Among various configurations, sPES(PAH/PSS)(4) membranes exhibited outstanding resistance and long-term stability (> 300 h) in 5 % HNO3, which potentially enables the recovery of 9100 g In and 6600 g Ag per m(2) of membrane. A life cycle assessment indicated a 34 %-46 % reduction in the global warming potential (GWP) of recycled Ag and a 40 %-50 % reduction for recycled In compared with the supply mix under modelled conditions. For Ag, the GWP was 137 g and 123 g CO2-eq/g at 70 % and 80 % LbL-NF permeate recovery, respectively. For In, the GWP was 50 g and 55 g CO2-eq/g at 70 % and 80 % recovery, respectively. These results highlight the climate benefits of LbL-NF membranes in circular resource recovery from end-of-life photovoltaics, which helps to identify key hotspots for optimisation and scale-up.

Antimony (Sb) has gained increased attention over the past few decades due to its possible detrimental effects on biota and its potential to leach and disperse from contaminated soils. The fate of Sb in the environment is largely controlled by its chemical speciation, as well as the speciation of solid phases (e.g. Mn/Fe-oxyhydroxides) that interact with Sb in soils. Microbes have the capacity to facilitate a multitude of oxidation and reduction reactions in soils. Therefore, they exert control over the reactivity of Sb in the environment, either directly and/or indirectly, by changing Sb speciation and/or affecting the redox state of soil solid phases. Here, we outline processes that determine the behaviour of Sb in soils. We conclude that based on laboratory studies there is a good theoretical understanding of pure soil components interacting with Sb species. However, comparatively little is known concerning the contribution of these interactions in complex natural systems that are dynamic in terms of biogeochemical conditions and that can hardly be simulated using laboratory incubations. We note that important biochemical foundations of microbially driven Sb conversions (i.e. molecular constraints on organisms, genes and enzymes involved) have emerged recently. Again, these are based on laboratory incubations and investigations in environments high in Sb. In this regard, an important remaining question is which microorganisms actively impact Sb speciation under real-world conditions, in particular where Sb concentrations are low. Multiple dissolved Sb species have been described in the literature. We note that more analytical development is needed to identify and quantify possible key Sb species in natural systems, as well as anthropogenically impacted environments with only moderate Sb concentrations. With these research needs addressed, we believe that the Sb fate in the environment can be more accurately assessed, and remediation options can be developed.

Perovskite solar cells (PSCs) are emerging as a particularly promising technology to enhance the world’s renewable energy generation capacity. As PSCs are transitioning from research to industrial-scale production, there is an important opportunity to establish sustainable manufacturing pathways. Here, we present a closed-loop framework for the development of environmentally sustainable PSCs and highlight strategies to achieve this vision. First, we analyse the sourcing of raw materials and compare two established PSC fabrication techniques, vapour-phase deposition and solution processing, evaluating their respective advantages and limitations in terms of economic feasibility and environmental impact. Second, we examine solution processing methods, focusing on solvent system design for the preparation of high-quality perovskite films and on the use of non-hazardous or less-hazardous solvents. Third, we examine potential lead-release concerns during PSC operation and discuss approaches to minimize associated environmental risks. Fourth, we summarize effective recycling methods for main PSC components to support a circular production model. Finally, we identify key challenges and outline future research directions to achieve fully sustainable, closed-loop PSC technologies. The transition of perovskite solar cells from laboratory research to industrial-scale production creates an important opportunity to prioritize sustainability. This Review introduces a closed-loop framework, addressing material sourcing, fabrication methods, solvent design, lead-risk mitigation, recycling strategies and future directions.

Due to minimal material use and low-cost processing, next-generation thin film solar cells represent a promising alternative to traditional crystalline silicon solar cells. Among these, metal-halide perovskite solar cells have seen significant improvements in power conversion efficiency and are now on the verge of market entry. However, most efficient and stable perovskite solar cells contain lead in the perovskite absorber layer, along with indium and silver in their electrodes. This study demonstrates an environmentally benign recycling process for recovering all three elements from end-of-life perovskite solar cells. In short, the process consists of mechanical dismantling (milling), aqueous extraction/purification of PbI2, and acid extraction and purification of indium and silver by nanofiltration. After the quantitative recovery of lead as PbI2 (95 ± 5%), indium and silver were dissolved using nitric acid with recovery rates of 87 ± 7% for both metals. Life cycle assessment calculations were used to determine optimal conditions in terms of minimal environmental impact per gram of extracted element. After acid extraction, nanofiltration was employed using both custom-made layer-by-layer membranes and commercially available acid-resistant flat sheet membranes to separate indium from silver. Using an optimized membrane design, indium was almost entirely retained (96.9 ± 0.4%) using a layer-by-layer membrane at 50% permeate recovery. Hence, a twofold concentration of indium was achieved over the course of the filtration. In contrast, silver was not retained (retention of -7.6 ± 6.3%), resulting in a dilute Ag permeate. Using the commercial flat sheet membrane resulted in similar retention rates, with 98.5 ± 0.4% for indium and 5.8 ± 11.6% for silver. However, this came at the expense of considerably higher operating pressure (25 bar vs 5 bar) and lower flux (6 L/m2h vs 30 L/m2h), resulting in higher energy demand (72 Wh/L vs 9 Wh/L). Therefore, layer-by-layer membrane filtration proved to be the superior method for element recovery from perovskite photovoltaic devices. This study has shown that combining hydrometallurgical processing (aqueous and acidic extraction) with layer-by-layer membrane filtration offers an efficient and environmentally benign approach for metal recovery from end-of-life solar cells. Since indium and silver are also key elements for other thin film photovoltaic applications, layer-by-layer membrane filtration may represent a platform technology for future photovoltaic panel recycling.

Selenium (Se) is an essential yet toxic trace element; it has one of the narrowest nutritional optimums of all elements. The speciation of Se significantly influences its mobility, toxicity, bioavailability, and bioaccumulation. Se environmental cycling has been generally understood as a sequence of bidirectional redox processes of Se species. Elemental Se (Se0) is considered a central species that is thermodynamically favoured in the redox conditions found in most environments. This study reports the identification of a novel group of dissolved species called polyselenylsulfides (with the general formula SexSy2-). These species form upon the reaction of Se0 with sulfide. Using derivatisation and ultrahigh-performance liquid chromatography electrospray ionisation quadrupole time-of-flight mass spectrometry, polysulfides (Sx2-, x = 2-6), selenide (Se2-), polyselenides (Sex2-, x = 2-3), and previously undetected polyselenylsulfides (SeS2-, SeS22-, Se2S2-, and SeS32-) were identified. The reaction was spontaneous and proceeded rapidly at alkaline pH (completed within <24 h). A slower and incomplete reaction was observed at circumneutral pH. The fast and spontaneous reaction down to circumneutral pH suggests the ubiquitous importance of polyselenylsulfides in sulfidic environments and calls for revising the environmental fate of Se. The existence of polyselenylsulfides challenges the traditional 'selenocentric' view, which focuses on specific, bidirectional redox reactions that only involve Se species. Moreover, the perception of Se0 as a terminal, insoluble species in many anoxic environments is questioned. The adoption of a 'chalcogenic' perspective is proposed, wherein the selenium and sulfur cycles are closely interconnected and the fate of Se is governed by the presence of sulfide.

In this chapter, the possible role and impact of organic and printed electronics (OPE) in a transition toward a circular economy and more sustainable society will be discussed. The learning targets are twofold: first, understanding main environmental issues associated with the emerging field of OPE, and second, identifying, through a systemic perspective, the enabling potential of these technologies.

Scandium (Sc) has various technological applications, but the concentrations of Sc in ores are low. Both, the mining of low concentrated Sc and the production of industrial-grade Sc are a heavy burden on the environment. Bauxite residue (BR) from alumina production represents one of the major sources of Sc in Europe (Ochsenk & uuml;hnPetropulu et al., 1994). The goal of this study is to assess the environmental impacts from cradle to gate of a novel production route developed in the Scandium Aluminium Europe project (SCALE) to extract Sc at concentrations <100 ppm from BR, to concentrate and upgrade it to pure ScF3 and Sc2O3 and ultimately to refine it to an aluminium scandium master alloy with 2 % Sc mass fraction (AlSc2 %). Results show that the global warming potential (GWP), measured in CO2-eq per kg Sc2O3, generated with the novel route is about half the GWP of the state-of-the-art Sc2O3 production from rare earth tailings when applying equal allocation principles. The initial process step to dissolve BR and extract Sc consumes elevated amounts of acid and energy and is responsible for at least 80 % of the route's total environmental impact. The amount of the generated filter cake (FC) is equal to the amount of the BR input and is a potential resource for cement clinker production. The ecotoxicological study indicates that both FC and BR are slightly ecotoxic.

A “redox-stat” RMnR bioreactor was employed to simulate moderately reducing conditions (+ 420 mV) in Sb-contaminated shooting range soils for approximately 3 months, thermodynamically favoring Mn(IV) reduction. The impact of moderately reducing conditions on elemental mobilization (Mn, Sb, Fe) and speciation [Sb(III) versus Sb(V); Fe2+/Fe3+] was compared to a control bioreactor RCTRL without a fixed redox potential. In both bioreactors, reducing conditions were accompanied by an increase in effluent Sb(V) and Mn(II) concentrations, suggesting that Sb(V) was released through microbial reduction of Mn oxyhydroxide minerals. This was underlined by multiple linear regression analysis showing a significant (p < 0.05) relationship between Mn and Sb effluent concentrations. Mn concentration was the sole variable exhibiting a statistically significant effect on Sb in RMnR, while under the more reducing conditions in RCTRL, pH and redox potential were also significant. Analysis of the bacterial community composition revealed an increase in the genera Azoarcus, Flavisolibacter, Luteimonas, and Mesorhizobium concerning the initial soil, some of which are possible key players in the process of Sb mobilization. The overall amount of Sb released in the RMnR (10.40

Selenium deficiency affects many million people worldwide and volatilization of biogenically methylated selenium species to the atmosphere may limit Se entering the food chain. However, there is very little systematic data on volatilization at nanomolar concentrations prevalent in pristine natural environments. Pseudomonas tolaasii cultures efficiently methylated Se at these concentrations. Nearly perfect linear correlations between the spiked Se concentrations and Dimethylselenide, Dimethyldiselenide, Dimethylselenylsulfide and 2-hydroxy-3-(methylselanyl)propanoic acid were observed up to 80 nM/L. The efficiency of methylation increased with increasing initial Se concentration, arguing that the enzymes involved are not constitutive, but methylation proceeds promiscuously via pathways of S methylation. From the ratio of all methylated Se and S species, one can conclude that between 0.30% and 3.48% of atoms were Se promiscuously methylated at such low concentrations. At concentrations higher that 640 nM (∼50 μg/L) a steep increase in methylation and volatilization was observed, which suggested the induction of specific enzymes. Promiscuous methylation at low environmental concentrations calls into question that view that methylated Se in the atmosphere is a result of a purposeful Se metabolism serving detoxification. Rather, the concentrations of methylated Se in the atmosphere may be “coincidental” i.e., determined by the activity of S cycling microorganisms. Further, a steep increase in methylation efficiency when surpassing a certain threshold concentration (here ∼50  μg/L) calls into question that natural methylation can be estimated from high Se spikes in laboratory systems, yet highlights the possibility of using bacterial methylation as an effective remediation strategy for media higher concentrated in Se.

Perovskite solar cells represent an emerging and highly promising renewable energy technology. However, the most efficient perovskite solar cells critically depend on the use of lead. This represents a possible environmental concern potentially limiting the technologies' commercialization. Here, we demonstrate a facile recycling process for PbI2, the most common lead-based precursor in perovskite absorber material. The process uses only hot water to effectively extract lead from synthetic precursor mixes, plastic- and glass-based perovskites (92.6 - 100% efficiency after two extractions). When the hot extractant is cooled, crystalline PbI2 in high purity (> 95.9%) precipitated with a high yield: from glass-based perovskites, the first cycle of extraction / precipitation was sufficient to recover 94.4 ± 5.6% of Pb, whereas a second cycle yielded another 10.0 ± 5.2% Pb, making the recovery quantitative. The solid extraction residue remaining is consequently deprived of metals and may thus be disposed as non-hazardous waste. Therefore, exploiting the highly temperature-dependent solubility of PbI2 in water provides a straightforward, easy to implement way to efficiently extract lead from PSC at the end-of-life and deposit the extraction residues in a cost-effective manner, mitigating the potential risk of lead leaching at the perovskites' end-of-life.

The lack of high-grade scandium (Sc) ores and recovery strategies has stimulated research on the exploitation of non-ore-related secondary sources that have great potential to safeguard the critical raw materials supply of the EU's economy. Waste materials may satisfy the growing global Sc demand, specifically residues from titanium dioxide (TiO2) production. New technologies are being developed for the recovery of Sc from such residues; however, the possible environmental impacts of intermediary products and residues are usually not considered. In order to provide a comprehensive ecotoxicity characterisation of the wastes and intermediate residues resulting from one promising new technology, acid-resistant nanofiltration (arNF), a waste-specific ecotoxicity toolkit was established. Three ecotoxicity assays were selected with specific test parameters providing the most diverse outcome for toxicity characterisation at different trophic levels: Aliivibrio fischeri (bacteria) bioluminescence inhibition (30 min exposure), Daphnia magna (crustacean) lethality and immobilisation (24 h exposure) and Lemna minor (plant) growth inhibition with determination of the frond number (7 d exposure). According to our results, the environmental impact of the generated intermediate and final residues on the aquatic ecosystem was mitigated by the consecutive steps of the filtration methods applied. High and statistically significant toxicity attenuation was achieved according to each test organism: toxicity was lowered based on EC20 values, according to the A. fischeri bioluminescence inhibition assay (by 97%), D. magna lethality (by 99%) and L. minor frond number (by 100%), respectively, after the final filtration step, nanofiltration, in comparison to the original waste. Our results underline the importance of assessing chemical technologies' ecotoxicological and environmental impacts with easy-to-apply and cost-effective test methods to showcase the best available technologies.

Scandium (Sc), declared a critical raw material in the European Union (EU), could face further supply issues as the EU depends almost entirely on imports from China, Russia, and Ukraine. In this study, a tandem nanofiltration-solvent extraction procedure for Sc recovery from titania (TiO2) acid waste was piloted and then augmented by antisolvent crystallization. The new process, comprising advanced filtration (hydroxide precipitation, micro-, ultra-, and nanofiltration), solvent extraction, and antisolvent crystallization, was assessed in relation to material and energy inputs and benchmarked on ScF3 production. From ∼1 m3 of European acid waste containing traces of Sc (81 mg L-1), ∼13 g of Sc (43% yield, nine stages) was recovered as (NH4)3ScF6 with a purity of approximately 95%, demonstrating the technical feasibility of the approach. The production costs per kilogram of ScF3 were lower than reported market prices, which underscores a competitive process at scale. Although a few technical bottlenecks (e.g., S/L separation and electricity consumption) need to be overcome, combining advanced filtration with solvent extraction and antisolvent crystallization promises a future supply of this critical raw material from European secondary sources.

Scandium is a raw material with properties that promise considerable potential for application in alloys to enable aviation fuel savings and as dopants for use in sustainable energy production using solid oxide fuel cells. Despite these attractive properties, scandium is rarely used due to its scarcity and unreliable supply. Therefore, new strategies for scandium recovery are of economic priority. In this study, polymer inclusion membranes (PIMs) consisting of PVDF-HFP, 2-NPOE and DEHPA, were optimised for selective scandium separation from real TiO2 production waste. With the optimised system, >60% of the scandium was recovered with high selectivity, resulting in scandium mole fraction at more than two orders of magnitude higher in the receiving phase than in the original waste. This suggests PIMs may be an effective way to recover scandium from bulk waste, thus easing the scarcity and insecurity that currently limit its bulk application.

Data soil characteristics ELECTRA. In all the datasets name, “ELECTRA” stands for the project acronym and grant number: “ELECTRA_826244_”

The relevance of extracellular magnesium in cellular immunity remains largely unknown. Here, we show that the co-stimulatory cell-surface molecule LFA-1 requires magnesium to adopt its active conformation on CD8+ T cells, thereby augmenting calcium flux, signal transduction, metabolic reprogramming, immune synapse formation, and, as a consequence, specific cytotoxicity. Accordingly, magnesium-sufficiency sensed via LFA-1 translated to the superior performance of pathogen- and tumor-specific T cells, enhanced effectiveness of bi-specific T cell engaging antibodies, and improved CAR T cell function. Clinically, low serum magnesium levels were associated with more rapid disease progression and shorter overall survival in CAR T cell and immune checkpoint antibody-treated patients. LFA-1 thus directly incorporates information on the composition of the microenvironment as a determinant of outside-in signaling activity. These findings conceptually link co-stimulation and nutrient sensing and point to the magnesium-LFA-1 axis as a therapeutically amenable biologic system.

Scandium is a critical raw material with a technological potential to reduce transportation costs and CO2 emissions. However, global supply and market adoption are crucially impaired by the lack of high-grade Sc ores and recovery strategies. A tandem nanofiltration solvent extraction route is demonstrated to enable effective Sc recovery from real-world acid waste from the chloride TiO2 production route. The process involving several filtration stages, solvent extraction, and precipitation was optimized, ultimately producing >97% pure (NH4)(3)ScF6.

Efficient and stable perovskite solar cells rely on the use of Pb species potentially challenging the technologies' commercialisation. In this study, the fate of Pb derived from two common perovskite precursors is compared to cationic lead in soil-water microcosm experiments under various biogeochemical conditions. The rapid and efficient removal of Pb from the aqueous phase is demonstrated by inductively coupled plasma mass spectrometry. Sequential soil extraction results reveal that a substantial amount of Pb is associated with immobile fractions, whereas a minor proportion of Pb may become available again in the long term, when oxygen is depleted (e.g. during water logging). X-ray absorption spectroscopy results reveal that the sorption of Pb on mineral phases represents the most likely sequestration mechanism. The obtained results suggest that the availability of leached Pb from perovskite solar cells is naturally limited in soils and that its adverse effects on soil biota are possibly negligible in oxic soils. All three Pb sources used behaved very similar in the experiments, wherefore we conclude that perovskite derived Pb will have a similar fate compared to cationic Pb, so that established risk assessment considerations for Pb remain legitimate.

Dietary organic selenium (Se) is commonly utilized to increase formation of selenoproteins, including the major antioxidant protein, glutathione peroxidase (GPx). Inorganic Se salts, such as sodium selenite, are also incorporated into selenoproteins, and there is evidence that nanoelemental Se added to the diet may also be effective. We conducted two trials, the first investigated inorganic Se (selenite), organic Se (L-selenomethionine) and nanoelemental Se, in conventional mice. Their bioavailability and effectiveness to increase GPx activity were examined. The second trial focused on determining the mechanism by which dietary Se is incorporated into tissue, utilising both conventional and germ-free (GF) mice. Mice were fed a diet with minimal Se, 0.018 parts per million (ppm), and diets with Se supplementation, to achieve 0.07, 0.15, 0.3 and 1.7 ppm Se, for 5 weeks (first trial). Mass spectrometry, Western blotting and enzymatic assays were used to investigate bioavailability, protein levels and GPx activity in fresh frozen tissue (liver, ileum, plasma, muscle and feces) from the Se fed animals. Inorganic, organic and nanoelemental Se were all effectively incorporated into tissues. The high Se diet (1.7 ppm) resulted in the highest Se levels in all tissues and plasma, independent of the Se source. Interestingly, despite being ~11 to ~25 times less concentrated than the high Se, the lower Se diets (0.07; 0.15) resulted in comparably high Se levels in liver, ileum and plasma for all Se sources. GPx protein levels and enzyme activity were significantly increased by each diet, relative to control. We hypothesised that bacteria may be a vector for the conversion of nanoelemental Se, perhaps in exchange for S in sulphate metabolising bacteria. We therefore investigated Se incorporation from low sulphate diets and in GF mice. All forms of selenium were bioavailable and similarly significantly increased the antioxidant capability of GPx in the intestine and liver of GF mice and mice with sulphate free diets. Se from nanoelemental Se resulted in similar tissue levels to inorganic and organic sources in germ free mice. Thus, endogenous mechanisms, not dependent on bacteria, reduce nanoelemental Se to the metabolite selenide that is then converted to selenophosphate, synthesised to selenocysteine, and incorporated into selenoproteins. In particular, the similar efficacy of nanoelemental Se in comparison to organic Se in both trials is important in the view of the currently limited cheap sources of Se.