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• Using the GRA-BILSTM prediction model in NEV battery recycling studies. • Studied the impact of different battery market shares on metal supply and demand. • Retired batteries have great potential for secondary use and material recovery. • Assessed the impact of metal recycling on the supply of key metals. • Assessing Key Metal Supply Risks Against Chinese and World Reserves. As Chinese new energy vehicle (NEV) sales continue to grow, end-of-life batteries have great potential for recycling in the future. In this study, a combined model based on Gray Relation Analysis and Bi-directional Long Short-Term Memory (GRA-BiLSTM) is proposed for predicting NEV sales, and the NEV battery life is modeled using the Weibull distribution. Then, the amount of end-of-life batteries, secondary utilization and metal recycling are calculated. The impact of end-of-life battery recycling on the supply and demand of key metals is studied. The results show that in 2040, the secondary utilization of end-of-life batteries in the Standard Growth Rate-Lithium Iron Phosphate Battery Dominated-High Secondary Utilization rate scenario (SGR-LFP H) is 391.76 GWh. The recycling volumes of lithium, nickel and cobalt are 45,900 tons, 92,900 tons and 22,100 tons, respectively. In the Standard Growth Rate-lithium nickel cobalt manganese oxide Battery Dominated-Low Secondary Utilization rate scenario (SGR-NCM L), the recycling of lithium, nickel and cobalt is even greater, at 62,600 tons, 372,200 tons and 71,700 tons, respectively. End-of-life batteries recycling can reduce the demand for metals. However, as NEV sales continue to grow, the gap between metal supply and demand remains significant. The findings urge the Chinese government develop appropriate battery management strategies to increase the recycling rate of end-of-life batteries; and to encourage enterprises to research new types of batteries to resolve the conflict between supply and demand for metals. [ABSTRACT FROM AUTHOR]

• Case study feasibility of real-time computer vision-based scrap metal separation. • Analysis of neural network architectures for recognition of forbidden scrap. • Proposal of a neural classifier analyzing a non-standardized stream of metal scrap. • Dataset augmentation for improved model robustness of a neural classifier. • Eliminating human in the detection of prohibited objects in copper-based scrap. Highly efficient industrial sorting lines require fast and reliable classification methods. Various types of sensors are used to measure the features of an object to determine which output class it belongs to. One technique involves the use of an RGB camera and a machine learning classifier. The paper is focused on protecting the sorting process against prohibited and dangerous items potentially present in the sorted material that pose a threat to the sorting process or the subsequent metallurgical process. To achieve this, a convolutional neural network classifier was applied under real-life conditions to detect forbidden elements in copper-based metal scrap. A laboratory stand simulating the working conditions in a high-speed scrap sorting line was prepared. Using this custom stand, training and test sets for machine learning were gathered and labeled. An image preprocessing algorithm was designed to increase the robustness of the resulting forbidden element detector system. The performance of multiple neural network architectures and data set augmentations was analyzed. The highest accuracy of 98.03% and F1-score of 97.16% were achieved with a DenseNet-based classifier. The results of this paper show the feasibility of using the presented solution on a high-speed industrial line. [ABSTRACT FROM AUTHOR]

This study explores the effects of using industrial-grade raw materials on the hydrogen storage properties of body-centered cubic (BCC) solid solution alloys. Industrial scrap metals were chosen as the raw material, and the desired alloys were synthesized using a vacuum arc melting furnace. Instead of using pure vanadium (V), different inexpensive industrial substitutes such as low-grade vanadium (V), vanadium nitride (VN), vanadium oxide (VO), and ferrovanadium (FeV) were utilized. The crystal structure, morphology, first hydrogenation, thermodynamics, and cyclability of the prepared alloys were analyzed by using XRD, SEM-EDS, and XPS methods. The crystal structure and morphology analysis revealed multiphase alloys in all the prepared alloys and a Ti rich third phase in the VN sample, which was absent otherwise. The first hydrogenation was performed at room temperature under a hydrogen pressure of 2 MPa without any prior heat treatment. The VO alloy displayed negligible hydrogen absorption during first hydrogenation, while the V, VN, and FeV alloys showed maximum hydrogen storage capacities of 3.49 wt%, 2.47 wt%, and 2.18 wt%, respectively. The presence of oxygen hinders the activation of the VO alloy and requires two activation cycles to activate the sample. A short-term cyclability analysis showed a reversible hydrogen storage capacity of 2 wt%. The change in enthalpy of hydrogen absorption and desorption for V alloy were calculated to be −36.73 ± 8.6 and 57.34 ± 8.3 kJ/mol H 2, respectively. One of the prominent advantages of utilizing scrap raw materials was the substantial reduction in overall raw material costs, which saw an impressive 95% decrease when compared to using pure raw materials. These results highlight the economic benefits of incorporating recovered industrial scrap into hydrogen storage alloys. • 52Ti–12V–36Cr + 4 wt% Zr alloy was prepared from industrial-grade raw material using arc melting. • Effect of the substitution of V with industrial scrap metal VN, FeV, and VO was studied. • Hydrogen storage capacity and the incubation period are affected by the impurities present. • Substitution with industrial raw materials can reduce the cost of hydrogen storage alloy by up to 95%. [ABSTRACT FROM AUTHOR]

• The incineration bottom ash fine fraction is a suitable secondary source of metals. • The wet shaking table concentrates up to 45 times the copper in the dense product. • The optimized device achieved recovery values of up to 70% for copper. • The obtained light mineral matrix has high concentration of elemental aluminum. Municipal solid waste incineration bottom ash has emerged as a secondary source of valuable metals, including aluminum and copper. Specifically, the fine fraction, with a particle size less than two millimeters, exhibits average grades of 2.5 g/kg for copper and 10.0 g/kg for elemental aluminum. Gravimetric concentration equipment, such as wet shaking tables, is widely used in the mining and recycling industries to concentrate materials based on density. However, the optimization of these devices typically relies on a trial-and-error approach. This paper presents a statistical model that optimizes the crucial working parameters of the wet shaking table for recovering elemental aluminum in a light product mineral matrix and copper in a high-density product. The statistical analysis highlights that upper values of shaking amplitude are beneficial for both the recovery and grade of copper and aluminum in the obtained products. Conversely, variations in other parameters, such as wash water or desk tilt, yield contrasting effects on grade and recovery. By precisely adjusting the working parameters of the device, the analyses demonstrate that copper enrichment of up to 45 times can be achieved in the product smaller than 500 µm and up to 15 times in the 500–2000 µm product, resulting in the recovery of approximately 65 % of the total copper. [ABSTRACT FROM AUTHOR]

Thermochemical water splitting is one of the methods to produce green hydrogen. In this study, metal scrap is used to split water by thermochemical process in a packed-bed reactor. Hydrogen production conditions are optimized by varying the particle size of the metal wastes in the range of 250 μm to greater than 1000 μm and the temperatures from 900 °C to 1200 °C. The maximum yield of hydrogen obtained is ∼500 mL of H 2 per gram of the scrap sample. This study demonstrates that the discarded metal wastes can be utilized as feed-materials for thermochemical production of green hydrogen. The process has good conversion efficiency and is a promising solution for both metal waste management and the production of green hydrogen. Medium size metal particles show higher hydrogen production capacity compared to both smaller (<250 μm) and larger (600–1180 μm) size particles. [Display omitted] • Hydrogen production using ferrous metal scrap materials. • Optimum size of ferrous scrap metal particles is in the range of 355–600 μm. • ∼500 mL of green hydrogen produced per gram of ferrous scrap materials at 1100 °C. [ABSTRACT FROM AUTHOR]

The thermal polymerization controlled the thickness and composition of graphic carbon nitride (g-C 3 N 4) to affect the photocatalytic performance. In this paper, potassium and sodium ions were firstly incorporated in bulk g-C 3 N 4 prepared using melamine through a mechano-chemical pre-reaction. After a two-step thermal polymerization treatment at 500 and 550 °C, respectively, superior thin g-C 3 N 4 nanosheets were created because K or Na ions implanted between g-C 3 N 4 layers, in which activated cites were remained in the nanosheets. The results revealed that potassium or sodium ion doping revealed an important impact on the photocatalytic activity of g-C 3 N 4. With an optimized K loading of 3%, the hydrogen evolution rate of potassium doped g-C 3 N 4 superior thin nanosheets was 18.1 times of that of bulk g-C 3 N 4. For the degradation of the degradation rate of Rhodamine B (Rh B), K-doped g-C 3 N 4 sample revealed 3.8 times increase compared with pure g-C 3 N 4. To indicate the role of alkaline metal ions, Na-doped samples were also used for H 2 generation and Rh B degradation. Meanwhile, the hydrogen generation and Rh B degradation rate of sodium doped g-C 3 N 4 nanosheets improved to 3.6 and 1.75 times higher than those of pure g-C 3 N 4 , respectively. The result suggested a mechano-chemical pre-treatment helped K and Na ions to improve the microstructure of g-C 3 N 4 nanosheets and increase activated cites for photocatalysis. [Display omitted] • K and Na were firstly incorporated in precursors through a mechano-chemical pre-reaction. • The precursors were treated by a two-step thermal polymerization to get g-C 3 N 4 nanosheets. • The superior thin g-C 3 N 4 nanosheets revealed enhanced H 2 generation and RhB degradation. • Increased activated cites from volume and surface defects play important role during photocatalysis. [ABSTRACT FROM AUTHOR]

Currently green hydrogen production is attracting global attention. In this context, sustainable hydrogen production processes have been explored by using variety of materials and methods. Generation of hydrogen without CO 2 emissions is the key for carbon-free energy economy in future. Enormous amounts of scrap iron, metallurgical wastes and ferrous metals are produced in industrial processes. In this work, the reaction between metal scrap and steam is studied for hydrogen production. The scrap materials are loaded in a packed-bed reactor to produce green hydrogen by water splitting at high temperatures. This method produced 500 mL of green H 2 per gram of scrap material at 1150 °C with a conversion efficiency of about 94%. This is a potential method to utilize the scrap metals for large scale production of green hydrogen without carbon emissions. [Display omitted] • Process of hydrogen production using metal scrap. • Generation of 500 mL of green hydrogen from 1 g of waste-scrap material. • Scalable process for extracting hydrogen from metal-waste. • Maximum hydrogen concentration measured is 924 μL of hydrogen per mL of outlet gas. [ABSTRACT FROM AUTHOR]

The global extraction of several billions of clean clay resources, which destroy millions square meters of land, is triggering environmental problems. Incorporating different dosages of incinerated waste or dredged sediment in bricks production has been studied by many researchers. Research articulating the combined effect of incinerated waste material (IWM) and river dredged sediments (RDS) addition on the performance of bricks is scarce. This paper aims to present findings on the engineering performance of fired bricks developed with the addition of IWM and RDS. In this regard, bricks were made with 5 wt% IWM and different dosages of RDS (i.e., 0 – 15 wt%). Physical, durability, mechanical, thermal and microstructure of the developed bricks is examined. Bricks' shrinkages were found meeting quality performance criterion in the 1.42 – 4.11% range. The highest bulk density of 1.85 g/cm3 permit to classify bricks obtained as lightweight. Water absorptions were mostly within the acceptable 20% tolerance level postulating the developed bricks high durability standard. Compressive strength reductions, which were confined within 5.28 and 21.57 MPa, showed the developed bricks applicability to structural weight-supporting construction as well as specialized engineering construction works. The 40.5% thermal conductivity reduction in WB15 bricks (at 800 °C) theorized its suitability for thermal insulation construction. Mineralogical and morphological analyses of fired bricks clearly showed kaolinite polymorphic phase transformation, which contributed to the different morphologies in the brick matrices. Consequently, reuse of IWM and RDS offered a chance to advance sustainable use of scarce clay resources in lightweight and thermal insulation brick production. • Performance of bricks made with incinerated waste and dredged sediment is studied. • Developed bricks showed linear shrinkages within the 1.42–4.11% quality limits. • The highest 17.87% absorptions of bricks fired at 1000 °C indicate good quality. • 21.57–5.28 MPa reductions in produced bricks' compressive strengths acceptable. • The up to 40.5% reduction in the bricks' conductivities good for insulation. [ABSTRACT FROM AUTHOR]

Tin-based compounds have garnered significant interest as anode materials for alkali metal secondary batteries due to their high theoretical capacities and low oxidation-reduction potential. Whereas, these materials are commonly vulnerable to harsh volume change and low conductivity as well as sluggish ion migration. In this work, the heterogeneous double-layer mesoporous hollow spheres SnSe 2 @N,Se-C were designed and synthesized to improve the inherent defects of tin-based compounds. When SnSe 2 @N,Se-C was applied as anode materials in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs), the discharge capacities of LIBs and SIBs after 500 cycles were 374.5 mAh g⁻1 and 307.8 mAh g⁻1 at 5 A g⁻1, respectively. Electrochemical kinetics test, structure characterization and finite element analysis confirm the double-layer mesoporous hollow spheres structure can provide buffer space to relieve volume expansion of SnSe 2 and offer mesoporous channel to promote ions diffusion, thus enhancing cycling stability and rate performance. The full cell SnSe 2 @N,Se-C//Na 3 V 2 (PO 4) 3 was assembled to verify its potential applications in SIBs, leveraging the enhanced capacity, rate ability, and durability offered by the unique structure of SnSe 2 hollow sphere coupled with mesoporous hollow carbon sphere. This work proposes an innovative anode material of SnSe 2 @N,Se-C for LIBs and SIBs, as same as serving as a valuable reference for the design of double-layer hollow spheres. [Display omitted] • Heterogeneous double-layer mesoporous hollow spheres SnSe 2 @N,Se-C are synthesized. • HDMHSs structure can shorten ions diffusion distance and alleviate volume expansion. • Doping Se strengthens the synergistic effect between HDMHSs structure and SnSe 2. • HDMHSs SnSe 2 @N,Se-C enhance electrochemical performances of Li/Na ion batteries. [ABSTRACT FROM AUTHOR]

This study investigates the effect of varying oxygen concentration on the secondary atomization of Galinstan. The concentration was varied between 0.0021 % and atmospheric concentration (21 %) and compared to water experiments in air where oxidation is not present. Independent of the oxygen concentration, we observe the known breakup morphologies of bag, bag-and-stamen, multimode breakup and shear stripping with similar transition Weber numbers. The results show that early stages during breakup remain unaffected by the oxygen concentration, given that droplets are initially fully oxidized. However, low oxygen environments in the bag, bag-and-stamen, and multimode breakup regimes lead to a later onset of breakup, larger droplet sizes at burst, and more pronounced deformation. In these conditions, Galinstan bags, rims, and, if present, stamens disintegrate more similarly to water. A key finding is the reduced particle size and more spherical particle shape of Galinstan at lower oxygen concentrations. In the shear stripping regime, oxygen concentration affects fragmentation only after the initial oxide layer of the droplet has been shed. Comparisons with water experiments reveal that decreasing the rate of oxidation results in Galinstan atomizing more similarly to common liquids such as water. [Display omitted] • Study oxygen concentration effect on liquid metal droplet breakup. • Low oxygen results in smaller and more spherical fragments. • Delayed onset of breakup for low oxygen concentration. • Transition Weber numbers remain unchanged for fully oxidized drops. [ABSTRACT FROM AUTHOR]

• Response Surface Methodology (RSM) is used to optimised parameters. • Mixture of Na 2 S and NaOH is used to leach Sb from stibnite tailings. • Scale up alkaline leaching tests are performed successfully. • H 2 O 2 is used to precipitate Sb from alkaline PLS. Nowadays, tailings management and scarcity of raw materials are both topics that are much discussed in the mining sector. Recycling is therefore a sustainable method of extracting metals from secondary resources for tailings management and the supply of critical metals such as antimony. Alkaline leaching was carried out using mixture of sodium sulfide (Na 2 S) and sodium hydroxide (NaOH). Optimisation tests at laboratory scale allow the optimum parameters to be set at 25 % pulp density, 0.97 M Na 2 S, 2.5 M NaOH, 70 °C, 300 rpm for 60 min. The antimony dissolution rates were 99.13 % and 97.00 % at bench and semi-pilot scale, respectively. On the other hand, hydrogen peroxide (H 2 O 2) was used to precipitate antimony from the leach solution. About 99 % of Sb precipitation efficiency was achieved under 5/1 Pregnant Leach Solution (PLS)/Hydrogen peroxide (H 2 O 2) ratio, 30 °C, 300 rpm for 90 min. [ABSTRACT FROM AUTHOR]

[Display omitted] • A snapshot on the Australia's mining industry and its waste/tailings is provided. • The role of accelerated mineral carbonation to decarbonize the industry is recognized. • The state-of-the-art AMC technologies for various mineral feedstocks are evaluated. • Commercial-scale technology deployment challenges and enabling factors are assessed. • A staged AMC technology roadmap comprising key players action plans is developed. While reacting CO 2 with sub-surface mafic/ultramafic phases potentially captures greenhouse gas emissions, low porosity and very slow kinetics makes this problematic. Mineral processing tailings and mining wastes offer distinct particles with exposed surfaces that enhance reactivity, and Australia's mining sector has numerous prospective tailings streams. Passive carbonation of such tailings is known, although reactivity is still usually low. This review evaluates the potential of accelerated mineral carbonation (AMC), engineered routes to facilitate mafic/ultramafic tailings carbonation. The state-of-the-art of AMC technologies are evaluated in terms of operational principles, advantages, process challenges and environmental impacts. After providing a snapshot of Australia's current mining industry, the best carbonation routes/practices for favorable rock types (e.g. wollastonite, serpentinite, olivine) are reviewed, highlighting their key Australian deposits or operations. Major challenges facing technology scale-up (CO 2 source, particle size and associated environmental risks) are analyzed. Integrating AMC with direct air capture (DAC) provides an adjacent pure, pressurized CO 2 stream to raise the viability of both technologies, while breakthroughs in secondary metal recovery or marketing carbonated end-products can also bolster business models. However, in the absence of supporting regulatory frameworks, major companies have been reluctant to adopt early-stage research, design and development to elevate AMC technologies toward commercialization. [ABSTRACT FROM AUTHOR]

We developed an eco-friendly method for synthesizing magnetic bimetallic-organic frameworks (MBOF) and applied it to an electrochemical sensor. The MBOF was synthesized using a simple electrochemical approach, helping to reduce the environmental impact of the manufacture. This electrosynthesis utilizes non-toxic salts, recyclable zinc electrodes, and mild reactions. By optimizing parameters such as current density, cathode material, electrolyte, and secondary metal ions, the yield of the MBOF was enhanced. Additionally, the crystal characteristics, chemical structure, and surface morphology of the MBOF can be adjusted by alternating the order of adding organic linkers and metal precursors. The MBOF was characterized through transmission electron microscopy, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction analysis. Anodic stripping voltammetry and ICP-AES were used to detect the incorporation of zinc and copper ions into the MBOF and to comprehensively evaluate the physical and chemical properties of this nanomaterial. The MBOF can be facilly modified with capture probes to detect two types of miRNA. This MBOF-based sensor exhibited a low detection limit of 0.018 fM for miRNA-21 and 0.068 fM for miRNA-3960, with a linear range extending from 0.01 fM to over 100 fM. This system demonstrated rapid analysis of multiple targets in serum, with excellent selectivity and stability, making it highly suitable for point-of-care diagnostics. This platform can also be applied for monitoring RNA or DNA viruses in the environment because of its sensitive detection of trace nucleotide sequences. [Display omitted] • MBOF is successfully fabricated by an eco-friendly electrosynthesis. • The MBOF-based biosensor detects a wide range of miRNAs from 10 aM to 100 fM. • The biosensor shows sensitive analysis with selectivity and 3-month stability. [ABSTRACT FROM AUTHOR]

• The expression for secondary fields produced by metal objects in AC magnetic field is derived. • A method to determine if eddy current interference exists based on phase shift is proposed. • A method of calibrating electromagnetic positioning system interfered by eddy currents is proposed. • Simulation experiments demonstrate the good calibration performance of the proposed method. Electromagnetic positioning technologies are frequently-used in surgical navigation systems to achieve precise position of surgical instruments in bodies. Still, in operating rooms with complex environments, they would be disturbed by eddy currents of metals. This paper explores a calibration method to mitigate eddy current interference. Initially, The study examined the generation mechanisms of eddy currents and established the expression of secondary magnetic fields they produced, which exhibited a 90-degree phase difference with the AC excitation field. Subsequently, an integral calibration method was proposed, leveraging fields' distinct phases for separating. Through simulation, various metal materials were modeled to study their impact on magnetic fields. The effectiveness of the calibration method was evaluated by comparing positioning accuracy before and after calibration. Results demonstrated over 80 % average calibration efficiency, effectively mitigating errors induced by metals and enhancing the system's reliability. This calibration method is crucial for the broader application of electromagnetic positioning systems. [ABSTRACT FROM AUTHOR]

This study reported the synthetic structural colors obtained by femtosecond laser-induced periodic bidirectional ripples on titanium film. Bidirectional ripples were obtained by secondary laser induction on the secondary deposited metal films. The pulse energy 1.5 μJ and the scanning speeds from 600 to 800 mm/s were selected as the best processing parameters to prepare bidirectional ripples. Considering that the ripple orientation affected the intensity of the color, the induced angle between the bidirectional ripples could be selected according to the range of information displayed. Moreover, the bidirectional ripples with an included angle of 90° were selected for color synthesis. The spectra of synthetic structural colors showed that abundant colors could be obtained through the simultaneous diffraction of bidirectional ripples. In addition, the synthetic structural colors changed with the lightness of the original structural colors. Therefore, this study provided a new idea to enrich the information display and realize the information security. • Bidirectional ripples were obtained by secondary laser induction on the secondary deposited metal films. • Abundant structural colors could be obtained through the simultaneous diffraction of bidirectional ripples. • The synthetic structural colors changed with the lightness of original structural colors. [ABSTRACT FROM AUTHOR]

In this study, we successfully isolated 11 species of cadmium-tolerant bacterium from Pu-erh rhizosphere soil, of which Staphylococcus equorum PU1 showed the highest cadmium tolerance, with a minimum inhibitory concentration (MIC) value of 500 mg/L. The cadmium removal efficiency of PU1 in 400 mg/L cadmium medium reached 58.7 %. Based on the Nanopore PromethION and Illumina NovaSeq platforms, we successfully obtained the complete PU1 genome with a size of 2,705,540 bp, which encoded 2729 genes. We further detected 82 and 44 indel mutations in the PU1 genome compared with the KS1039 and KM1031 genomes from the database. Transcriptional analysis showed that the expression of 11 genes in PU1 increased with increasing cadmium concentrations (from 0 to 200, then to 400 mg/L), which encoded cadmium resistance, cadmium transport, and mercury resistance genes. In addition, some genes showed differential expression patterns with changes in cadmium concentration, including quinone oxidoreductase-like protein, ferrous iron transport protein, and flavohemoprotein. Gene Ontology (GO) functions, including oxidation reduction process and oxidoreductase activity functions, and KEGG pathways, including glycolysis/gluconeogenesis and biosynthesis of secondary metals, were also considered closely related to the extreme cadmium tolerance of PU1. This study provides novel insight into the cadmium tolerance mechanism of bacteria. • A strain with extreme tolerance to cadmium was isolated from Pu-erh rhizosphere. • The cadmium removal efficiency of PU1 in a 400 mg/L cadmium medium reached 58.7 %. • The genome of PU1 and genetic variations with salt tolerant species was analyzed. • Mechanisms of PU1 response to different concentrations of cadmium were revealed. • This study furthers our understanding of adsorption mechanism of bacteria to cadmium. [ABSTRACT FROM AUTHOR]

• Tin in e-waste was efficiently separated and recycled by a novel two-stage CVT process. • The conversion of sn-SnO(g)-SnO 2 during staged oxidation was revealed. • The inhibition mechanism of O 2 content on SnO disproportionation was revealed. • Tetragonal nano-SnO 2 with a crystallinity of 99.9% was obtained from e-waste. E-waste is a valuable resource for the recovery of secondary metals. However, traditional methods only focused on the extraction of Cu and noble metals (Au, Ag, etc.), and significant tin (Sn) loss occurred during the smelting or the leached. In this paper, a novel chemical vapor transport (CVT) process was proposed to separate and recycle Sn from e-waste to prepare nano-SnO 2. The effect of roasting parameters on Sn volatilization and characterization of nano-SnO 2 were investigated using thermodynamic analysis, XRD, SEM, TEM, etc. The results indicated that Sn volatilization of 92.8 % was obtained under optimal roasting parameters under CO-CO 2 -N 2 atmosphere. In addition, nano-SnO 2 with a crystallinity of 99.9 %, an average grain size of 24.8 nm and a specific surface area of 97.9 m2/g was synthesized successfully. [ABSTRACT FROM AUTHOR]

This study focused on removing chemical oxygen demand and phenol from petroleum wastewater by employing the electrocoagulation (EC) process using scrap electrodes. In the study, in a unique way different from those reported in the literature, scrap cylindrical perforated iron (PS) and plate metals discarded by different industries were used as electrodes by recovery for EC. PS was used the anode, and plate electrodes made of two different materials (Al and Fe) were used as the cathodes. The electrodes were placed at the center of the EC reactor and PS. The effects of the main parameters, namely, initial pH (4−10), initial exposure time (5–45 min), and current density (2–28 mA/cm2), on the EC process were assessed and optimized by employing response surface methodology (RSM). A reasonable correlation between the experimental and predicted data was found through analysis of variance (ANOVA). The ANOVA results revealed that the coefficients of determination (R2) for COD removal and phenol removal were 91.18% and 91.46%, respectively. The maximum predicted removal efficiency rates were 96.18% and 94.02% for respectively COD and phenol under the optimum conditions of pH= 6.30, current density= 22 mA/cm2, exposure time= 39 min, and the Fe cathode. Furthermore, the results showed that the initial current density and exposure time were significantly effective on COD and phenol removal from petroleum wastewater. The total cost was calculated as $3.1/m3. There was no electrode cost in the study due to the usage of scrap metals. The results indicated that the EC process is an effective treatment method for COD and phenol removal from petroleum wastewater using scrap metals as electrodes. [Display omitted] • EC process using waste metal perforated scrap of Fe for petroleum wastewater removal. • Efficiency COD and phenol removal by recovered scrap metals. • The use of waste metal scrap as electrodes reduced the overall cost of the treatment process. [ABSTRACT FROM AUTHOR]

Copper-exchanged CHA zeolite serves as a commercial catalyst for NO x selective catalytic reduction (SCR) in diesel aftertreatment systems, where the intercage transfer of Cu ions is crucial for the catalyst's low-temperature performance, particularly at temperatures below 200 °C. This study reveals that the strategic modulation of copper sites in Cu-SSZ-13 via manganese migration significantly enhances the low-temperature SCR efficiency for NO x reduction. Mn2+ cations engage in a competitive occupation with Cu2+ cations for the most energetically favorable locations adjacent to the six-membered rings (6MR) within the zeolitic framework. Quantitative EPR and ICP analysis reveal that introducing 0.20 wt% Mn into Cu-SSZ-13 transforms Cu species from 6MR to predominantly 8MR binding, and a linear relationship was established between the amount of Cu in 8MR with reaction rate at 150 °C. The significance of this work lies in the development of a strategy to modulate the location and distribution of Cu ions in zeolites through the introduction of a secondary metal. [Display omitted] • Core-shell MnCeTi@Cu-SSZ-13 was synthesized via sol-gel method for SCR catalyst. • Mn ion migration competes with Cu2+ for energetically favorable sites in zeolite structure. • EPR and ICP quantifiy 0.20 wt% Z 2 MnⅡ transforms ZCuIIOH from 0.29 to 1.46 wt%. • Enhanced ZCuIIOH content linearly correlates with improved LT-SCR reaction rate. • Operando studies highlight ZCuIIOH-promoted NH 2 NO formation for higher N 2 yield. [ABSTRACT FROM AUTHOR]

The objective of this study is to investigate the catalytic activity of metal–organic framework (MOF) materials with core–shell structures, specifically focusing on particles of varying sizes and their application in the carbon dioxide cycloaddition reaction. [Display omitted] • Investigates the catalytic performance of metal–organic frameworks (MOFs) with core–shell structures. • Examines how variation in core–shell catalyst influence catalytic efficiency. • Explores the cycloaddition of CO 2 with epoxides for cyclic carbonate synthesis, aiding in carbon emission reduction. The primary objective of this study is to investigate the catalytic activity of metal–organic framework (MOF) materials, particularly those designed with core–shell structures. The study will focus on how variations in particle sizes of core–shell catalysts influence the catalytic performance. A key application under investigation is their ability to facilitate the cycloaddition of carbon dioxide (CO 2) with epoxides, a reaction that holds significant promise for the synthesis of cyclic carbonates. Results show that reducing the size of silica spheres increases the specific surface area and improves catalytic activity. SiO 2 -1μm@ZIF-67 exhibited the highest turnover frequency (TOF) of 52, significantly outperforming other samples. Adding secondary metals, such as Fe and Cu, maintained the structural integrity of ZIF-67 and the bimetallic core–shell structure demonstrated excellent stability and reusability, making it a promising candidate for industrial applications. This process not only provides a sustainable pathway for CO 2 utilization but also aligns with global efforts to mitigate carbon emissions through chemical recycling. By systematically analyzing different MOF particle sizes, we aim to gain insights into the relationship between size, structure, and catalytic efficiency, thereby advancing the development of more effective catalysts for CO 2 transformation. [ABSTRACT FROM AUTHOR]

In this study, an iron-air battery recycling system is reported, capable of recovering both lithium and cobalt, as well as energy, from spent LiCoO2 cathode materials, with the separation reaction being completely spontaneous. Meanwhile, lithium and cobalt were successfully recovered from the powdered leach solution of spent LiCoO2 cathode material, and it was preliminarily demonstrated that spent iron could serve as a sacrificial anode for the system. [Display omitted] • Innovative application of iron-air batteries for recycling of used lithium batteries. • The recovery rates of Li+ and Co2+ are as high as 1.49 mg h−1 and 18.75 mg h−1, respectively. • The system provides its own energy without external supply. • The system can sustain stable operation for over 24 h, with an output energy density reaching 5.89 Wh m−2. The widespread application of Lithium-ion Batteries (LIBs) has led to a significant increase in the number of spent LIBs. Consequently, the recycling and utilization of spent LIBs have become an inevitable choice for recovering valuable resources and protecting the environment, aligning with the principles of sustainable development. This study reports an iron air battery recycling system that is capable of recovering both Li/Co and energy from spent LiCoO 2 cathode materials and the separation reaction is completely spontaneous. Meanwhile, lithium and cobalt were successfully recovered from the powdered leach solution of spent LiCoO 2 cathode material, and it was preliminarily demonstrated that spent iron could be used as a sacrificial anode for the system. Several key parameters affecting recovery are optimized, including anode solution pH, discharge current density, and concentration of the solution to be recovered. Under the conditions of anode solution pH of 1.8, discharge current density of 0.1 mA cm−2, and concentration of recovery solution of 0.15 mol/L, the system can be operated stably for more than 24 h, and the recoveries of Li+ and Co2+ can be up to 1.49 mg h−1 and 18.75 mg h−1 respectively, and the output energy can reach 75.15 kJ/mol. This research not only provides a sustainable and cost-effective method of disposing of used lithium-ion batteries, but also offers up new possibilities for the disposal of scrap iron. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Ni-P thin layer coating is uniformly distributed over the surface of the pumice particles with a size of 50 μm. • High oxide levels have a negative effect on tensile and hardness properties, as revealed by the FESEM image. • Highest tensile strength of 198.9 MPa and hardness of 130 HV are achieved for Ni-P coated pumice composites. • Scrap Al alloy reinforced with coated pumice (2 wt%) particles enhances mechanical properties. The present research attempts to investigate the mechanical properties of scrap aluminium (Al1100) metal matrix composites reinforced with electroless Ni-P-coated and uncoated pumice particles. The fabrication of composite samples involves the use of stir casting procedures, where scrap aluminium alloy is used as the matrix material and both Ni-P coated and uncoated pumice particles are used as reinforcements. By using the electroless method to coat the Ni-P on the pumice particle surface, which enhances the wetting and improves the bonding between the matrix material and reinforcement. Four types of composite samples, i.e., scrap aluminum (RAS) without reinforcement, parent aluminium (As-cast) without reinforcement, and scrap aluminium alloy reinforced with coated and uncoated pumice (2 wt%) particles. Pdcl 2 and sodium hypophosphite are used to prepare the bath for the electroless Ni-P coating, in that Pdcl 2 acts as the surface activation agent. Based on trial runs, the pumice particles are selected with a size of 50 μm for Ni-P particle coating purposes. To analyze the tensile strength and surface morphology of AMMC samples using field emission scanning electron microscopy (FESEM) images and X-ray diffraction (XRD). From the results, it is observed that the highest value of tensile strength, 198.9 MPa, and hardness value, 30 HV, are achieved for scrap aluminium matrix reinforced with Ni-P coated pumice particles compared to other AMMC samples. [ABSTRACT FROM AUTHOR]

The ingenious doping of Cu into cobalt oxides with a hierarchical structure and spinel phase has facilitated the creation of oxygen vacancies (O v) and the modulation of the electronic configuration within CuCoO x -20, which greatly improved the redox property of the catalyst, thus achieving improved activity and kinetics for PMS activation and antibiotic degradation under ambient conditions. [Display omitted] • Co-doping of Cu atoms and oxygen vacancy was achieved in CuCoO x catalysts. • CuCoO x -20 showed excellent capability for PMS activation. • CuCoO x -20 displayed high efficiency and recyclability for TC degradation. • The unique spinel phase endows CuCoO x -20 with high resistance to perturbations. • Both radical and non-radical pathways were involved during TC degradation process. Novel oxygen vacancies-enriched bimetallic spinel oxides were designed and constructed to boost refractory antibiotic degradation in surface water through peroxymonosulfate (PMS) assisted advanced oxidation processes (PMS-AOPs). The construction of oxygen vacancy (O v) and the regulation of the electronic structure was achieved by the innovative doping of Cu into cobalt oxides with a spinel phase and hierarchical structure, and the antibiotic degradation activity and mechanism was systematically investigated. Over the CuCoO x -20/PMS system, up to 98.85 % degradation of tetracycline (TC) was achieved within 10 min, with a rate constant of 0.433 min−1, which is 3.3-fold and 7.5-fold higher than those of cobalt oxides and copper oxides, respectively. Comprehensive characterization and density functional theory (DFT) calculations have elucidated that the oxygen vacancies in CuCoO x -20 could not only bolsters the activation of PMS through enhanced adsorption and electron transfer between PMS and Co sites but also expedites the redox cycling of Co2+/Co3+ during advanced oxidation processes. This work provides a case study for the enhancement of PMS activation over metal oxides through the co-doping of a secondary metal and oxygen vacancies, which is significant for the elimination of hard-to-degraded wastewater and the ecological environmental protections. [ABSTRACT FROM AUTHOR]

[Display omitted] • A highly efficient bi-metallic MOF adsorbent with a large surface area was synthesized. • Only up to 2 mol % of Cu metal can be successfully substituted with Mg metal in MOF-199. • Polyethyleneimine (PEI) was incorporated into bi-metallic MOF to alter its pore size and environment. • The bi-metallic MOF composite loaded with 40 wt% PEI showed highest CO 2 /N 2 adsorption selectivity. The fine-tuning of metal–organic frameworks (MOFs) can enable the development of effective adsorbents for the selective capture of less polarizable carbon dioxide (CO 2) from flue gases. In this work, a series of bi-metallic MOFs with different Mg metal concentrations (1–10 mol%) were synthesized by in situ metal substitution followed by post-synthetic functionalization with 10–50 wt% of polyethyleneimine (PEI). Detailed characterization confirmed the successful incorporation of the secondary metal and amine group into the MOF framework. Results showed that only up to 2 mol% of copper (Cu) can be substituted by Mg metal in the framework of MOF-199; further increase in Mg content disrupts the electrostatic equilibrium, leading to the formation of carbon matter-based copper nanoparticles instead. The sorption results indicated that 2 mol% Mg-doped MOF (MOF@Mg2) demonstrate a CO 2 uptake of 8.61 (mmol/g) at 1 bar and 273.15 K. This reflects a 17.78 % increase in CO 2 absorption capacity compared to the pristine MOF. Furthermore, 40 wt% PEI-loaded MOF exhibited a 37.90 % enhancement in CO 2 adsorption selectivity. This study explores in detail the intricate process of optimizing the metal ratio and PEI loading in the bimetallic MOF-199(Cu, Mg), aiming to improve its CO 2 adsorption efficiency. [ABSTRACT FROM AUTHOR]

[Display omitted] • Activation of the depressed minerals in cyanide tailing by several activators. • Comprehensive consideration to the reasonable flotation condition for the recovery of the valuable metals from some solid wastes. • Recovery of heavy metals from the secondary resources by the combination of flotation and other techniques. • Several challenges and opportunities faced in recycling heavy metals using flotation technology. Due to the stringent environmental regulations requiring proper disposal of the wastes, recycling/removing heavy metals from solid wastes and wastewater has attracted the worldwide attention. Flotation tends to be one of the promising techniques that have enjoyed widespread use because of its high yield, low cost, and ease of operation. This article provided an overview of the present application status of flotation in the recovery/removal of heavy metals from secondary resources such as tailings, waste printed circuit boards, slags, lithium-ion batteries, leach residue and wastewaters. The study was focused on the reagent regimes and physicochemical & electrochemical mechanism of flotation, in particular, the application of single and hybrid process was reviewed. Finally, the paper has pointed out challenges and future perspectives of the flotation application in metal recovery from secondary resources. Hence, this work aims to promote the development of flotation technology to recover heavy metals from secondary resources. [ABSTRACT FROM AUTHOR]

[Display omitted] • Three nitrogen-rich sulfur-containing adsorbents were firstly prepared. • The three adsorbents have excellent adsorption uptake, selectivity and recycling. • Increasing the N content could increase the adsorption performance. • The spatial structure also has a significant impact on the adsorption performance. • The adsorption mechanism involves electrostatic effect, coordination, and redox. Recovering precious metals from secondary resources has elicited considerable attention, and exploring an efficient adsorbent is a challenge. In this work, we have specifically tailored three highly effective adsorbents (THDA@PEI, DCTA@PEI and DCTD@PEI) by crosslinking PEI with sulfur-containing heterocyclic cross-linking agents (2,5-thiophenedicarboxaldehyde, 2,4-dichlorothiazole and 3,4-dichloro-1,2,5-thiadiazole) for recovery of Au(III), Pd(II), and Pt(IV). These agents are distinguished by a range of nitrogen atom counts that extend from zero to two, offering a foundation for exploring the correlation between their molecular structure and adsorption performance. THDA@PEI, DCTA@PEI, and DCTD@PEI exhibit remarkable adsorption capacities for Au(III), Pd(II), and Pt(IV), with values reaching up to 2169, 2240, and 2536 mg/g for Au(III), 771, 886, and 846 mg/g for Pd(II), and 832, 1021, and 887 mg/g for Pt(IV), respectively. Among the three materials, DCTD@PEI stands out with a broader pH applicability range for both gold (pH 2 to 9) and platinum (pH 1 to 11) adsorption and exhibits a more rapid adsorption rate for Au and Pd. The adsorption processes of the three adsorbents on precious metals are spontaneous and entropy-increasing processes. Increasing the adsorption temperature could improve the adsorption performance of the three adsorbents, except for Pd adsorption by DCTD@PEI. All of the three adsorbents exhibit good selectivity and reusability for Au, Pd, and Pt, with DCTA@PEI being the most outstanding. It is observed that an increase in nitrogen content in the adsorbents correlates positively with the improvement of key performance indicators, including a wider pH range, higher adsorption capacity, faster kinetics, better selectivity, and enhanced reusability, while the substituent positions of crosslinking agents also have a strong impact on the adsorption performance, especially for Pd and Pt. [ABSTRACT FROM AUTHOR]

Reclamation of copper from waste printed circuit boards (WPCBs) is critical in advancing eco-friendly manufacturing methods by considering viable secondary metal resources. Herein, this study introduced a novel hybrid intelligence model that relies on a support vector regression–grey wolf optimization (SVR-GWO) approach to predict, validate, and optimize the leaching of WPCBs in nitrate solution and copper purification using LIX 973 N. The hybrid model's performance surpassed that of the standalone SVR model due to fine-tuning hyperparameters using the GWO approach, as indicated by the lower values of MSE and narrow error distribution in the leaching, extraction, and stripping experiments. The modeling data indicated that 96.1 % of the copper in the WPCB material was dissolved during leaching at 75°C, using a pulp density of 7 % for 2 h. During the extraction phase, the hybrid model optimized the structure performance of equilibrium pH, extractant concentration, contact time, and O/A ratio, resulting in values of 2.5, 30 %, 20 min, and 1, respectively. The predicted isotherm data for the McCabe-Thiele diagram, derived from the developed model, suggested four operational stages for extracting copper from the leach solution. Under optimized conditions of 2 M H 2 SO 4 and 0.3 A/O phase ratio at 25 °C for 20 min, the complete stripping process from the loaded organic phase required applying three counter-current stages. These developments highlight the capability of the SVR-GWO method to improve copper extraction from WPCBs, thereby making a substantial contribution to sustainable recycling efforts. [Display omitted] • Hydrometallurgy processes in conjunction with the hybrid machine learning algorithm. • Novel structural optimization system-based SVR-GWO model for spent PCBs recycling. • Implementation of HNO 3 recycling from the leaching solution for reusing application. • Investigation of the interactive effects of operational variables on Cu recovery. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO 2) and methane (CH 4) are the primary greenhouse gases (GHGs) that drive global climate change. CO 2 reforming of CH 4 or dry reforming of CH 4 (DRM) is used for the simultaneous conversion of CO 2 and CH 4 into syngas and higher hydrocarbons. In this study, DRM was investigated using Ag–Ni/Al 2 O 3 packing and Sn–Ni/Al 2 O 3 packing in a parallel plate dielectric barrier discharge (DBD) reactor. The performance of the DBD reactor was significantly enhanced when applying Ag–Ni/Al 2 O 3 and Sn–Ni/Al 2 O 3 due to the relatively high electrical conductivity of Ag and Sn as well as their anti-coke performances. Using Ag–Ni/Al 2 O 3 consisting of 1.5 wt% Ag and 5 wt% Ni/Al 2 O 3 as the catalyst in the DBD reactor, 19% CH 4 conversion, 21% CO 2 conversion, 60% H 2 selectivity, 81% CO selectivity, energy efficiency of 7.9% and 0.74% (by mole) coke formation were achieved. In addition, using Sn–Ni/Al 2 O 3 , consisting of 0.5 wt% Sn and 5 wt% Ni/Al 2 O 3 , 15% CH 4 conversion, 19% CO 2 conversion, 64% H 2 selectivity, 70% CO selectivity, energy efficiency of 6.0%, and 2.1% (by mole) coke formation were achieved. Sn enhanced the reactant conversions and energy efficiency, and resulted in a reduction in coke formation; these results are comparable to that achieved when using the noble metal Ag. The decrease in the formation of coke could be correlated to the increase in the CO selectivity of the catalyst. Good dispersion of the secondary metals on Ni was found to be an important factor for the observed increases in the catalyst surface area and catalytic activities. Furthermore, the stability of the catalytic reactions was investigated for 1800 min over the 0.5 wt% Ag-5 wt% Ni/Al 2 O 3 and 0.5 wt% Sn-5 wt% Ni/Al 2 O 3 catalysts. The results showed an increase in the reactant conversions with an increase in the reaction time. • Addition of Ag or Sn to the Ni/Al 2 O 3 catalyst suppressed coke formation during the DRM. • Good dispersion of Ag and Sn on the Ni/Al 2 O 3 catalyst is an important factor. • 19% CH 4 and 21% CO 2 conversions were achieved with 1.5 wt% Ag on Ni/Al 2 O 3 catalyst. • 15% CH 4 and 19% CO 2 conversions were achieved with 0.5 wt% Sn on Ni/Al 2 O 3 catalyst. • The decrease in coke formation could be correlated to the increased CO selectivity. [ABSTRACT FROM AUTHOR]

Increasing discharge of saline wastewater (SWW) from different industries and environmental risks associated with it has compelled researchers to search for efficient treatment methods and safe disposal techniques. Unfortunately, several industries such as agro-food, oil & gas, tannery, and pulp & paper require brine solution units to obtain a finished product that further elevates the salinity of discharged wastewater to a magnitude of 1-3% by weight of NaCl. Among the conventional treatment procedures, electrochemical technologies proved to be more efficient, robust and cost-effective. Electrocoagulation (EC), an electrochemical based technology that produces in situ coagulant which ultimately assist in pollutant removal. It is even more suitable for the treatment of saline water as salinity increases conductivity which further enhances the EC process efficiency. However, the elevated anodic dissolution may increase the cost which can be reduced by using scrap metals as sacrificial electrodes out of iron and aluminum. The mechanism of salt removal from SWW using EC is similar to other pollutant removal mechanisms as salt species being coagulated by the metal hydroxides and are further removed as sludge. However, optimization of process parameters in EC is essential to maintain a balance between anodic passivation and higher metal dissolution so as to make the process efficient. This review paper highlights the theory of the EC technology, process parameters, potential application and recent developments of EC for the treatment of various types of SWW as well as economical assessment associated with this technology. Most of the recent research concerning EC for SWW treatment has been concentrated on the pollutant-specific evaluation without paying special attention to the process optimization, process modeling and commercial usage. This review further outlines the challenges with the recommendations for encouraging research options that can potentially enhance the EC performance, lower the operational costs and expand its range of applications for SWW treatment. [ABSTRACT FROM AUTHOR]

• Describes a methodology to assess data in the informal e-waste sector in Ghana. • A method for rapid data assessment is provided. • Annual e-waste mass flows at Agbogbloshie Scrapyard range between 13,090 and 17,094 t/a. • Roughly 39% of the Ghanaian e-waste generation is treated at Agbogbloshie Scrapyard. The Old-Fadama-Scrapyard, better known as Agbogbloshie, is located in Accra, Ghana. Over the last 20 years, the area has developed into a large scrapyard, where the informal sector processes mainly electronic waste (e-waste) and scrap metals. However, unsafe treatment methods, such as the open burning of cables and foams, and the spilling of hazardous liquids onto the ground, cause environmental pollution and create health risks by releasing persistent organic pollutants (POPs) and heavy metals. There is a recognized lack in literature of data on e-waste mass and material flows due to the lack of applicable methods to measure e-waste quantities in an informally managed treatment system. However, to establish sustainable e-waste management, e-waste mass and material flow data are crucial prerequisites. Therefore, the material flow analysis (MFA) methodology is proposed as a means for data collection within a limited time frame in the informal e-waste recycling context. In this case study, mass and material flows of e-waste processed at Agbogbloshie were estimated using two different approaches: Firstly, the kind, measures, constitution of load and number of loaded entering and exiting vehicles was observed and documented, and second, to validate the data collected, the mass and material flow of e-waste treatment processes on site were observed and documented. The resulting annual mass flows range between 13,090 t/a and 17,094 t/a of e-waste. Based on the data for Ghana from the Global E-waste Monitor, an average of 15,092 t/a (approximately 39% of the Ghanaian e-waste generation) is treated in Agbogbloshie. [ABSTRACT FROM AUTHOR]

• Effects of Ni-based catalysts and calcined dolomite on H 2 production were studied. • Catalyst support and secondary metal affected the performance of Ni-based catalyst. • Simultaneous catalysis and sorption was better than sequential catalysis and sorption. • Calcined dolomite offset catalytic activity difference of varied Ni-based catalysts. • Bimetallic catalysts were more effective when combined use with calcined dolomite. The effects of addition of various Ni-based catalysts and their combination with calcined dolomite on H 2 -rich gas production were investigated during catalysis/sorption enhanced pyrolysis-gasification of sawdust. It was found that catalyst support greatly affected the catalytic performance of Ni-based catalysts, the highest H 2 concentration and yield was obtained by NiO/SiO 2 , followed by NiO/γ-Al 2 O 3 and NiO/ZSM-5. Additional active sites on Ni-based catalyst would be formed by introduction of secondary metals onto NiO/γ-Al 2 O 3. Positive synergistic effect between secondary metals and Ni was observed, especially for Mg and Co, resulting in further improved H 2 production. Calcined dolomite was further introduced into the process to enhance H 2 production, simultaneous catalysis and sorption was found to be better for H 2 production than sequential catalysis and sorption. The addition of calcined dolomite could offset the catalytic performance difference for varied Ni-based catalysts due to its catalysis/sorption enhancing effect. Comparatively, bimetallic catalysts were more effective than monometallic catalysts when combined use with calcined dolomite, the H 2 concentration was significantly improved despite of the slight changes in H 2 yield. Ni-Cu/γ-Al 2 O 3 and Ni-Zn/γ-Al 2 O 3 with good performance on WGS reaction showed better synergistic effect with calcined dolomite, a highest H 2 concentration of 87.06 vol.% was achieved by Ni-Cu/γ-Al 2 O 3 catalyst. [ABSTRACT FROM AUTHOR]

[Display omitted] • Na 2 MoO 4 modification of SrLi 2 Ti 6 O 14 is prepared by simple impregnation and heat treatment. • The formation of conductive interface layer can improve the electrochemical properties. • SrLi 2 Ti 6 O 14 @Na 2 MoO 4 composite shows long cycle stability. In order to improve the ionic and electronic conductivity of zero strain material SrLi 2 Ti 6 O 14 (SLTO). In this work, a new type of anode material with Na 2 MoO 4 (NMO) surface modification of SLTO composite was prepared by simple impregnation and heat treatment. Due to the formation of an enhanced conductive interface layer between NMO and SLTO, NMO modified SLTO composites show higher reversible capacity and good rate performance than pure SLTO. After 100 cycles at 100 mA/g, the reversible capacity of SLTO@NMO(0.15g) composite is 144 mAh/g, while that of pure SLTO is 106 mAh/g. Especially, the SLTO@NMO(0.15g) composite exhibits long cycle stability, with a delithiation capacity of 100 mAh/g after 1800 cycles of testing at 5 A/g. Considering the low cost of NMO and the easy operation of surface modification, this method can be applied to improve the conductivity of other alkali metal secondary battery materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bismuthate pre-catalyst undergoes surface reconstruction to expose more active Bi0 sites. • The secondary metal sites tend to stabilize at the edge sites of Bi defects. • FE HCOOH exceeds 90 % in the current density range of −10 to −400 mA cm−2 on Bi/M catalysts. • FE HCOOH reaches maximum of 94.3 % at –400 mA cm−2 on Bi/Ca catalyst. Bismuth-based materials have emerged as promising electrocatalysts for the electrochemical reduction of carbon dioxide (eCO 2 RR) to HCOOH. However, it remains challenges to meet the practical application requirements and identify the active sites of bismuth-based catalysts in eCO 2 RR. Herein, bismuthate (MBi 2 O 4 , M = Ca, Cu, Zn) derived nanosheet-like electrocatalysts with metal-modified edge defects are developed. During electrochemical processes, MBi 2 O 4 pre-catalyst undergoes surface reconstruction to expose more active Bi0 sites and to form abundant metal-modified edge defects, which facilitate the modulation of charge state of adjacent Bi sites and improve the adsorption of *OCHO intermediate, thereby enhancing the selectivity of eCO 2 RR towards HCOOH. The Ca-modified defect-rich Bi catalyst exhibits a maximum HCOOH Faradaic efficiency of 94.3 % at an industrially relevant current density of 400 mA cm−2, together with high stability/reproducibility of 55 h. This work proposes a new strategy for construction of Bi-based catalysts and explores its structural reconstruction mechanism during the electrocatalytic process, opening a new window for design of eCO 2 RR catalysts. [ABSTRACT FROM AUTHOR]

When the proportion of reinforcing phases is high and the wettability between the secondary phase and the metal is poor, preparing fully dense particle-reinforced metal matrix composites becomes challenging. This study employs the flash sintering method to prepare fully dense WCu20 composite materials within a few tens of seconds. It is found that during the "thermal runaway' process of flash sintering, the Cu phase undergoes rapid melting and solidification, and the core mechanism of material densification is that pressure causes Cu liquid to quickly fill the gaps between tungsten particles. Pressure not only promotes the contraction of the framework formed by tungsten particles but also facilitates the complete filling of gaps within the tungsten frameworks by the Cu liquid and promotes the rapid expulsion of bubbles from the Cu liquid, thereby achieving rapid densification of WCu20 composite materials. Moreover, an increase in the temperature enhances the fluidity of the Cu liquid, which aids in filling the gaps between tungsten particles and promotes the discharge of bubbles from the Cu liquid. Flash sintering is a common technique for the sintering and densification of metal powders, suitable for the rapid preparation of various metal matrix composites. • Fully dense WCu20 materials were prepared by flash sintering within 20 s. • Pressure has a core impact on the densification of flash sintering process. • The effect of the highest temperature on densification is studied. [ABSTRACT FROM AUTHOR]

Roll bonding is a well-established solid-state joining method that has also found commercial use. In current industrial practice, a near-perfectly bonded interface is commonly aimed for, achieved by optimizing surface preparation and rolling parameters. On the other hand, an intriguing recent study has shown that roll bonding scrap metal has the potential to provide significant environmental benefits while not jeopardizing performance, despite the resulting imperfect interface with a distribution of cavities. This present work focuses on the mechanical aspects of this observation, aiming to provide a deeper understanding of the influence (or lack thereof) of the cavity content on the mechanical behavior of a roll bonded stainless steel, and a roll bonded mild steel. Imperfectly bonded samples of both steels are studied using mechanical tests and microstructure characterization, which both revealed that the interface cavities exhibit limited growth and no crack nucleation or propagation into the interface. A numerical finite element model of the imperfectly bonded sheet confirmed a tendency for low cavity growth by showing that opening stresses on the interface cavity remain low for various geometries and loading conditions, in line with linear elastic fracture mechanics calculations. Overall, this experimental-numerical study provides insights regarding the unexpected formability (and thus the wide applicability) of imperfectly roll bonded sheets. [Display omitted] • No continuous oxide layer was observed after roll bonding steel specimens. • Interface cavities of imperfectly bonded steel show limited growth upon straining. • Simulations and LEFM validate this cavity behavior for various loading states. • The overall failure of the interface exhibited ductile fracture characteristics. [ABSTRACT FROM AUTHOR]

• PB and hydrogels were simultaneously conducted via coordination-driven self-assembly. • PB/AlHs@Fe composite mesh possessed the respective functions of PB and hydrogels. • PB/AHs@Fe composite mesh could reduce secondary pollution of metal ions in AOPs. • PB/AHs@Fe composite mesh exhibited excellent underwater supreoloephobic property of OCA of 156°. • PB/AHs@Fe composite mesh presented the superior performance in oil/water separation and degradation of MB. The treatment of oily wastewater has become an urgent problem. In the process of water treatment, the superhydrophilic and underwater superoleophobic filter meshes offer attractive advantages because of the efficient separation efficiency and easy industrialization. Here, a stable superhydrophilic and underwater superoleophobic Fe composite mesh coated by Prussian blue/alginate hydrogels (PB/AHs@Fe composite mesh) was successfully prepared via coordination-driven in-situ self-assembly. PB/AHs@Fe composite mesh combined the advanced oxidation processes (AOPs) activity of PB with the hydrophilic property of alginate hydrogels (AHs). This composite mesh exhibited the exceptional self-cleaning performance through the activation of peroxymonosulfate (PMS) and H 2 O 2. In this self-cleaning process, the concentration of metal ions was reduced by 82% owing to the strong cross-linking effect between AHs and metal ions for decreasing the secondary pollutions. Simultaneously, PB/AHs@Fe composite mesh showed a good underwater oil contact angle (OCA>156°). And the composite mesh demonstrated outstanding oil/water separation performances, such as 99.5% of separation efficiency and 180,000–280,000 L m−2 h−1 of water flux. Besides, PB/AHs@Fe composite mesh exhibited outstanding stability, durable alkaline resistance, and salt resistance in oil/water separation process, which made it a potential material for the application of oil/water separation and self-cleaning performance. A stable superhydrophilic and underwater superoleophobic Fe composite mesh coated by Prussian blue/alginate hydrogels (PB/AHs@Fe composite mesh) was successfully prepared via coordination-driven self-assembly and used for oil/water separation and self-cleaning performance. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Potentially toxic elements of AMOLED display in smartphones were identified. • Alkaliphilic bacteria potential of usage in bioleaching was thoroughly evaluated. • Diverse assemblage of organic acids was produced in the modified Horikoshi medium. • Sequential extraction test showcased the required condition to extract each metal. • 100, 56.8 and 41.4% of Ag, Mo, and Cu were extracted at high pulp density in 12 days. With the alarming rate of e-waste generation, resource recovery from secondary metal sources is essential for sustainable resource utilization and to prevent the release of potentially toxic elements into the environment. In the current study, the first-time extraction of Ag, Mo, and Cu from active-matrix organic light-emitting diode (AMOLED) screens of discarded smartphones have been achieved using organic acids produced by Bacillus foraminis cultured on a modified Horikoshi medium. The influences of initial pH, inoculation size, and pulp density on the bioleaching process were evaluated over six-day experiment. Maximum extraction of Ag, Mo, and Cu (100, 56.8, and 41.4%) at optimal values of three investigated factors was obtained over a 12-day bioleaching experiment. A diverse assemblage of organic acid was produced in the optimized bioleaching condition, including tartaric (12.1 mM), formic (49.8 mM), acetic (21.5 mM), lactic (78.5 mM), citric (2.7 mM), and propionic (69.6 mM) acid. The contact angle analysis highlighted more hydrophobicity of powder after the bioleaching. FTIR and CHNO data also confirmed the role of bioleaching in the powder wettability alteration. The sequential extraction method revealed high mobility of In, Fe, Co, Cu, Cr, and Mo and low mobility of Ag. The results exhibited high tolerance of alkali-tolerant bacteria to potentially toxic elements and its superior performance in the bioleaching of discarded mobile screens at high pulp density. [ABSTRACT FROM AUTHOR]

• A small sample non-ferrous metal target detection model was proposed. • Improved YOLOv3 model was compared with traditional image recognition model. • Recognition accuracy of aluminum and copper scraps was 95.3% and 91.4%. • Separation accuracy and purity are all more than 90% in the optimal condition. Consumption of copper and aluminum has increased significantly in recent years; therefore, recycling these elements from the end-of-life vehicles (ELVs) will be of great economic value and social benefit. However, the separation of non-ferrous materials is difficult because of their different sources, various shapes and sizes, and complex surface conditions. In experimental study on the separation of these materials, few non-ferrous metal scraps can be used. To address these limitations, a traditional image recognition model and a small sample multi-target detection model (which can detect multiple targets simultaneously) based on deep learning and transfer learning were used to identify non-ferrous materials. The improved third version of You Only Look Once (YOLOv3) multi-target detection model using data augmentation, the loss function of focal loss, and a method of adjusting the threshold of Intersection over Union (IOU) between candidate bound and ground truth bound has superior target detection performance than methods. We obtained a 95.3% and 91.4% accuracy in identifying aluminum and copper scraps, respectively, and an operation speed of 18 FPS, meeting the real-time requirements of a sorting system. By using the improved YOLOv3 multi-target detection algorithm and equipment operation parameters selected, the accuracy and purity of the separation system exceeded 90%, meeting the needs of actual production. [ABSTRACT FROM AUTHOR]

• Waste 1D-FeOOH adsorbent has been firstly reused as efficient electro-catalyst for PMS activation. • The used 1D-FeOOH with adsorption of Mo ions showed the highest PMS activation ability. • The •OH and SO 4 •− was found to be the primary radical for MTD degradation during PMS activation. • 1D-FeOOH@Mo showed high PMS activation ability for its stable adsorption nature, easy electron transfer and weak O O bond. • PMS electro-catalysis activation mechanism and MTD degradation pathway have been proposed. Peroxymonosulfate (PMS) activation have provided a new direction to eliminate the organic pollutant. Current challenges that must be solved include secondary pollution by the metal ions and limitation in the recyclability of the catalysts. The waste 1D-FeOOH adsorbent with adsorption of metal elements (As, Cr or Mo ions) has been reused as an efficient electro-catalyst for PMS activation and used to metronidazole (MTD) degradation for the first time. The effects of current density, initial reaction pH, stirring rate, PMS dosage and solution temperature on MTD degradation was studied. The used 1D-FeOOH with adsorption of Mo ions showed the highest PMS activation ability and 99.6% MTD could be removed after 30 min degradation. The •OH and Found that SO 4 •− is the main free radical for MTD degradation. DFT calculation and characterization results were demonstrated that the high PMS electro-catalysis activation ability of the 1D-FeOOH@Mo has resulted from the special composition-dependent interactions among FeOOH@Mo and PMS, including stable adsorption properties, easy electron transfer and weak O O bond. The possible PMS electro-catalysis activation mechanism and MTD degradation pathway have been proposed. (ECOSAR) was used to evaluate the toxicity of metronidazole during degradation. The results showed that the toxicity of MTD and its intermediates could be effectively reduced by prolonging the degradation time in 1D-FeOOH@Mo solution. This work provides new insights for waste adsorbent disposal and gives a new perspective for PMS activation to degradation of antibiotics in water. [Display omitted] [ABSTRACT FROM AUTHOR]

Mill scale scrap, which contains vast amounts of valuable metals, is a solid waste produced in the iron and steel industry. Conventional mill scale scrap treatment methods for metal extraction are characterized by high energy consumption and low value addition. In this study, co-treatment of mill scale scrap and manganese ore via the oxidization roasting-magnetic separation process was investigated for the synchronous preparation of higher-value materials and recovery of valuable metals. Thermodynamic and magnetism analyses indicated that a higher temperature (>1100 °C) and a MnO 2 /Fe 2 O 3 molar ratio of 0.75–1 are essential for the preparation of manganese ferrite. The experimental validation revealed that soft magnetic manganese ferrite powders with a purity of 97.5 wt% were obtained when the test was conducted at 1300 °C for 120 min, followed by a two-stage grinding and magnetic separation process; the corresponding yield and the Mn and Fe recoveries were 78.99 wt%, 86.14 wt%, and 84.60 wt%, respectively. During the oxidization process, [Fe2+]O was initially oxidized to the anti-form spinel-type structure of [Fe3+][Fe2+Fe3+]O 4 , and thereafter, it reacted with the decomposition product of [Mn3+][Mn2+Mn3+]O 4 to form a hybrid spinel-type structure [Me2+ x Me3+ l-x ][Me2+ 1-x Me3+ 1+x ]O 4 (Me refers to Mn and Fe) via the Mn2+/Fe2+/Mn3+/Fe3+ ions exchange at the tetrahedral and octahedral sites. Moreover, the as-purified ferrite can be used as an ingredient for the preparation of high-performance MnZn ferrite. Image 1 • A sustainable treatment of mill scale scrap and manganese ore is presented. • Valuable metals in the scrap and manganese ores are synchronously recovered. • The formation mechanism of manganese ferrite is discussed. • Oxidization roasting and magnetic separation regimes are systematically studied. • Mn and MnZn ferrites with good electromagnetic performance from scrap are obtained. [ABSTRACT FROM AUTHOR]

• DEM-FEM co-simulation was adopted to analyze a separation system. • Impact of operation parameters and scraps shape on separation distance was studied. • Numerical simulations are capable to accurately describe the separation systems. End-of-life vehicles (ELVs) provide a particularly potent source of non-ferrous metal scraps. At presents, conveyor belt and air-jet nozzle are widely used in the existing separation system for non-ferrous metal scraps. Parameters such as shape of the scraps, conveyor belt speed (v), nozzle air pressure (P) and nozzle angle (α) have a significant influences on the separating accuracy and efficiency. To investigate the interaction between these parameters and their influences on the separation distance, a coupled simulation model of (Discrete Element Method) DEM and (Finite Element Method) FEM was employed to simulate the motion of the scraps and the separation process, the trajectory of the scraps under different circumstances was recorded and analyzed, the simulation model was verified using a separation platform. The results indicated that block shaped scraps have the largest separation distance followed by rod and slice shaped scraps. The separation distance of rod and slice shaped scraps increases when each of the three parameters increases, and the speed of conveyor belt (v) plays a dominant role. For blocks shaped scraps, when nozzle pressure is high, the separation distance increase with the increase of conveyor belt speed, when nozzle pressure is low, the separation distance decrease with the increase of conveyor belt speed. The nozzle pressure (P) was found to have the most noticeable impact on separation distance for block shaped scraps. For the platform in this study, the optimal operation parameters obtained were v = 1.9 m/s, P = 0.53 MPa, and α = 42°. [ABSTRACT FROM AUTHOR]

• An integrated approach for WPCB recycling using pyrolysis and ultrasonication. • Recovery of the metallic fraction is around 90% • Gaseous product obtained mainly consists of H 2 , CH 4 , CO and CO 2. • The first report on the metallic fraction recovery from WPCB using ultrasonication. • Chemical-free recycling of WPCB. Electronic waste (e-waste) with an annual growth rate of 3–5% is one of the fastest-growing waste streams. The unregulated accumulation and improper recycling can cause grave hazards to human beings and the environment. On the contrary, e-waste can be considered as a secondary source of metals and energy due to its high metal content and polymeric material. Thus, the present study demonstrates technology for the metallic fraction recovery and the production of valuable gases from e-waste. The process involves pyrolysis at a temperature range of 200 °C–600 °C in a fixed bed setup for 10–60 min. Under optimized operating conditions, 35 wt% combustible gases and 60 wt% solid product were obtained at a pyrolysis temperature of 400 °C in 20 min. The gaseous product consisted of CH 4 , H 2 , CO and CO 2 , having the heating value 28 MJ/kg whereas, the solid product is a mixture of metals and other solid residue material. Treatment of the solid product using an ultrasonication process resulted in around 90 wt% recovery of metallic fraction, thereby leaving behind solid residue. Moreover, the transfer of precious metals (Au, Ag, Pd and Pt) was nearly 100% to the metallic fraction. This process combines mild temperature pyrolysis and ultrasonication process to provide a solution for efficient management of e-waste, metallic fraction recovery and valuable gases production. [ABSTRACT FROM AUTHOR]

• MNi/CNTs with controlled metal distribution was successfully synthesized. • The secondary metal M had profound effects on reducibility and surface property. • CoNi/CNTs showed the best abilities in anti-sintering and coke resistance. • Hydrogen was more selective over CoNi/CNTs by promoting water gas shift reaction. The bimetallic MNi/CNTs (M Co, Cu and Fe) catalysts with controlled metal distribution were prepared by a two-step impregnation method. The catalysts were characterized by N 2 adsorption/desorption, XRD, XPS, TPR, HAADF-STEM, TEM and TG to study the porous structure, changes in crystalline phases during the reaction, surface chemical state, reducibility, the element distribution, sintering of metal particles and the deposited coke for the calcined and/or spent catalysts. The results showed that the Ni oxide was successfully introduced into the cave and the other one was dispersed on the external wall of CNTs. The addition of the secondary metals had significant influences on the reducibility, resulting in the quite different surface properties which was directly linked to the products distribution in glycerol reforming reaction. The sample CoNi/CNTs performed better in both anti-sintering and coke resistance, and over which the product was more selective to hydrogen by enhancing the water gas shift reaction. [ABSTRACT FROM AUTHOR]

• Equilibrium calculations reveal propane dehydrogenation (DH) activity is enhanced by using CO 2 as a co-feed. • Alumina supported V 2 O 5 modified with CrO x , MoO y and WO z were examined for propane DH in the presence and absence of CO 2. • XPS and TPR studies show that the supported mixed oxide species were non-interacting. • The best DH catalyst was supported CrO x and no promotional effect was observed for the mixed metal oxide catalysts. • When CO 2 was co-fed with propane, MoO y and WO z modified supported V 2 O 5 showed promotion of C 3 H 6 yield, whereas CrO x did not. Oxidative dehydrogenation (ODH) of propane was investigated using CO 2 as an oxidant. Thermodynamic equilibrium calculations revealed the beneficial effect of using CO 2 on propane conversion. In order to increase the propene selectivity, alumina supported vanadia catalysts modified with secondary metal oxides viz., chromia, molybdena and tungsta were synthesized. The catalyst characterization using temperature programmed reduction (TPR) and X-ray photoelectron spectroscopy confirmed the non-interacting nature of the metal oxides in the mixed oxide form. Additionally, TPR study of reoxidized catalysts indicated that CO 2 was able to only partially reoxidize the reduced active sites in contrast to O 2. These catalysts showed similar redox property in individual as well as in mixed metal oxide form reconfirming their non-interacting nature in mixed oxides. The synthesized catalysts were examined for propane dehydrogenation in the absence and presence of CO 2. Chromia was found to be the best catalyst for dehydrogenation reaction in the absence of CO 2. Moreover, no synergy was obtained in mixed oxide catalysts. Feeding CO 2 with propane had no beneficial effect on the propene formation rates for the chromia modified supported vanadia catalyst, whereas, the molybdena and tungsta modified vanadia catalyst showed an improved propene formation rate. [ABSTRACT FROM AUTHOR]

Niobium, Zr, REE, and Y are widely enriched in the Upper Permian coal-bearing strata in southwestern China and are regarded as a substantial resource. To better understand the occurrence modes and enrichment mechanisms of these rare metals, comprehensive heavy-mineral separation, Micro-Raman spectroscopy, EPMA, and LA-ICP-MS analyses of primary and secondary metal minerals were conducted in the polymetallic beds in western Guizhou. In addition, the XRD, XRF, and ICP-MS analyses of bulk rocks were carried out. Our results suggest that Nb is primarily hosted in secondary TiO 2 polymorphs which converted from primary Nb-rich rutile, and occurs as minor ilmenorutile and columbite-(Fe). The Zr is sequestered in both detrital zircon and secondary microcrystalline zircon. REE and Y (REY) are mainly incorporated into secondary florencite-(Ce), rhabdophane-(Ce), churchite-(Y), and zircon, also partially adsorbed by clay minerals. The assemblage of detrital zircon, Nb-rich rutile, and discrete Nb minerals reveals that rare metals are preconcentrated during the waning-stage Emeishan alkaline magmatisms. Complex zonings in rutile crystals may result from the diffusion of Nb5+ and Fe2+, and these grains are further overprinted by magmatic-hydrothermal and enveloped by ilmenorutile and columbite-(Fe). Furthermore, magmatic rutile is commonly converted into anatase, brookite, and leucoxene under supergene conditions, and then persisted as stable phases. Authigenic REY-rich (Al)-phosphates and zircon are sourced from the leaching, even decomposition of primary REY-phosphates and zircons. Their colloidal aggregates are precipitated from the acidic and oxidizing low-temperature fluids, which are superposed onto clay matrix. The mineralogical and geochemical features suggest that the polymetallic beds are enriched by both alkaline magmatic-hydrothermal processes in source rocks and supergene fluid alterations in sediments. This study gives new insights into the enrichment processes and conditions, and further extraction of critical metals in the coeval coal-bearing strata in southwestern China. [Display omitted] • LA-ICP-MS revealed the composition and origin of primary and secondary metal minerals. • Waning Emeishan alkaline magmatic-hydrothermal processes preconcentrated rare metals. • Protracted alkaline magmatism and TiO 2 phase transition control the enrichment of Nb. • Secondary REY (Al)-phosphates and zircon are formed by alteration of acidic fluids. [ABSTRACT FROM AUTHOR]

The development of new high-performance anode materials for lithium/sodium secondary batteries is still one of the most important tasks. Herein, kejten black modified 3D-framework ternary metal molybdate NaMnFe(MoO 4) 3 was successfully synthesized by solid-state reaction combined with mechanical ball milling and first exploited for lithium/sodium-ion battery anodes. As tested for lithium-ion batteries, NaMnFe(MoO 4) 3 -ketjen black composite demonstrated a high reversible capacity of 800 mA h g−1 at 100 mA g−1 after 50 cycles due to its high valence construction of polymetallic elements. While investigated for sodium-ion batteries, the as-prepared composite electrode delivered 215 mA h g−1at 100 mA g−1 after 100 cycles. Notably, after 800 cycles of continuous cycling, the reversible sodium storage was 155 mA h g−1 and 134 mA h g−1 at current densities of 0.5 A g−1 and 1 A g−1, respectively. In terms of long life results, the NaMnFe(MoO 4) 3 -ketjen black composite is more suitable for sodium-ion batteries than lithium-ion batteries. Because of the advantages of low cost, simple synthesis steps and mass production, NaMnFe(MoO 4) 3 -ketjen black composite has tremendous potential for application in alkali metal secondary batteries, especially sodium-ion batteries. Meanwhile, this work also provides inspiration for the application of other new polymetallic molybdate materials in the field of energy storage. [Display omitted] [ABSTRACT FROM AUTHOR]

• ML and H 2 S increased the accumulation of anthocyanin and phenolic compounds under as stress. • ML and H 2 S decreased the expression of PT2 and Lsi1 and declined as accumulation under as toxicity. • ML and H 2 S increased the expression of GSH1, PCS , and ABC1 and sequestered as in the roots. • ML and H 2 S strengthened the antioxidant defense system and improved chlorophyll metabolism. The multifunctional roles of melatonin (ML) and hydrogen sulfide (H 2 S) as plant gasotransmitters are well understood. However, their interaction in defensive responses is still unclear. Here, we assessed how the ML-H 2 S interaction impacts tomato plants exposed to arsenic (As, 10 mg/L) toxicity. The results showed that ML and ML+H 2 S treatments alleviated As toxicity by inducing the transcription of ANS, PAL, DFR, CHS , F 3 H, and CHI and an enhanced accumulation of phenolic and anthocyanin compounds. ML and ML+H 2 S led to a drop in the transcription of PT2 and Lsi1 , resulting in reduced As uptake and subsequent movement to the leaves. ML and ML+H 2 S treatments resulted in high GSH1, PCS , and ABC1 transcription. This led to elevated levels of glutathione and phytochelatins, facilitating As sequestration in the roots and protecting root and leaf cells against As. ML and ML+H 2 S treatments enhanced tomato growth under As treatments by optimizing chlorophyll metabolism, increasing internal H 2 S, and amplifying the antioxidant machinery function. In contrast to the sole use of ML treatment, ML+H 2 S exhibited more pronounced positive impacts on As-stressed tomatoes, indicating synergistic/interactive effects between these two substances. On the other hand, the use of hypotaurine, an H 2 S scavenger, demonstrated the inhibition of the beneficial impact of ML and ML+H 2 S treatments in stimulating defensive responses, which highlights the substantial involvement of H 2 S in the signaling pathway activated by ML during As stress. Hence, we can conclude that ML requires the presence of endogenous H 2 S to mitigate the adverse effects of As on tomato seedlings. [Display omitted] [ABSTRACT FROM AUTHOR]

The mining industry is crucial to the current global economy; however, it confronts sustainability challenges. Recovering secondary metals from mining residues is a promising opportunity to enhance the sustainability of the mining sector. This paper introduces a Life Cycle Sustainability Assessment (LCSA) to evaluate the sustainability of a new valorization process designed for a residue from a sulfidic mine located in Sweden. Results show mixed environmental impacts, with higher climate change (+22%) but lower mineral resource use (-98%) compared to primary mining. Economic analysis suggests that with a CAPEX between 80 M€and 120 M€, the final NPV is between 8.2 M€and 48 M€, depending on the purity of the recovered cobalt. Social analysis reveals fair worker compensation and limited access to local resources as crucial social risks. In the case study presented in this paper, the LCSA provides valuable insights for future cleaner production and more sustainability-oriented decision-making. • A Sustainability assessment evaluates mining residues valorization development. • The LCA, except for climate change and land use, shows clear benefits. • The purity of recovered cobalt is the key driver to economic viability. • Fair salary and access to local resources are the main social hotpots. [ABSTRACT FROM AUTHOR]