Search Results (1,384)

In this work, iron–phosphorus-based composite biochar (FPBC) was prepared by modification with the leachate of spent LiFePO₄ batteries. The effects of solution pH, dosage, adsorption time, initial concentration, and temperature on the adsorption performance of FPBC were investigated by batch adsorption experiments with Pb(II) and Sb(III) as the target pollutants, and the adsorption mechanism was explored using SEM, BET, XPS, FTIR and XRD characterization. The results indicated that as the initial pH of the solution increased, the removal efficiency of FPBC for Pb(II) gradually increased, while the removal efficiency for Sb(III) remained largely unchanged. The removal of Pb(II) and Sb(III) by FPBC fitted the pseudo-second-order kinetic model and the three-step intraparticle diffusion model, indicating that their removal was primarily controlled by chemical adsorption. Isothermal adsorption studies revealed that FPBC adsorption of Pb(II) better fitted the Langmuir and D-R models, suggesting a monolayer-dominated adsorption process. In contrast, adsorption of Sb(III) fitted the Langmuir, Freundlich, and Temkin models, suggesting a combination of monolayer and multilayer adsorption characteristics. The maximum adsorption capacities of FPBC for Pb(II) and Sb(III) were 312.54 mg·g⁻¹ and 219.20 mg·g⁻¹ at 30 °C, which were approximately 12.85 and 3.37 times those of commercial corn stalk biochar (BC). Thermodynamic analysis confirmed that the removal of Pb(II) and Sb(III) by FPBC was a spontaneous and endothermic process. In addition, FPBC demonstrated strong selective adsorption of Pb(II) in the binary co-adsorption system of Pb(II) and Sb(III). Mechanism studies indicated that Pb(II) removal primarily occurred through co-precipitation, complexation, ion exchange, and electrostatic adsorption, while Sb(III) was mainly adsorbed by FPBC via redox reactions and complexation. Therefore, this work not only provides a low-cost, high-performance adsorbent for the remediation of water contaminated with Pb(II) and Sb(III), but also opens up new avenues for the resource recovery of the leachate of spent LiFePO₄ batteries. Full article

Developing reliable processing routes for semiconductor thin films is essential for advancing photodetection technologies. The amine-thiol solvent system, in comparison with other liquid-phase synthesis methods, does not necessitate stepwise ion-exchange reactions. It is capable of obtaining the target semiconductor thin film by directly dissolving bulk powder followed by subsequent annealing. Although PbO can be dissolved in this solvent as a raw material to obtain PbS thin films, the structural evolution, optical properties, and photodetection performance of the films obtained via this solvent system still require further exploration. This solvent system was employed to prepare PbS thin films, and a comprehensive investigation was carried out on the evolution of their structure, morphology, and optical properties during preheating and annealing treatments. During preheating, the films exhibit directional ordering within the organic matrix, which converts into phase-pure PbS upon annealing. Based on the optimized films, interdigitated photodetectors and hybrid devices integrated with graphene transistors are fabricated. The resulting devices exhibit strong photoresponse and operational stability, demonstrating the viability of amine-thiol-processed PbS films for photodetection applications. Full article

Citric acid (CA) necessitates the investigation of the environmental footprint from its production. This study compared three recovery technologies at different readiness levels, industrial calcium hydrogen salt precipitation–ion exchange (CHP-IE), pilot-scale solvent extraction (SE), and laboratory-scale bipolar membrane electrodialysis (BMED), to evaluate the life cycle environmental impacts of CA production when employing each recovery technology. SE and BMED were selected as emerging alternatives, as both are potential candidates to offer environmental or economic advantages over CHP-IE. By modeling the continuous improvement in the key production parameters as cumulative production experience increases, technological learning curves capture the efficiency gains that occur as technologies mature. This study pioneers an integrated ex-ante LCA framework that couples technological learning curves with energy transition scenarios to prospectively compare emerging CA recovery technologies against an industrialized process. Currently, CHP-IE shows the highest profit of 1078 CNY/t CA and the lowest global warming potential (GWP) of 1.79 t CO₂ eq/t CA, with the latter advantage projected to persist until 2030. By 2050, under deep decarbonization, BMED becomes the lowest-carbon option with 0.78 t CO₂ eq/t CA. Furthermore, with maize as the primary raw material, improved cultivation models in Northeast China reduce the environmental impacts of CA production by approximately 3% in acidification potential (AP) and eutrophication potential (EP), while diversified cropping systems in North China yield reductions of over 50% in these two categories. This paper provides an approach of comprehensive evaluation, supporting technology selection and green supply chain development in the CA industry. Full article

Nutritionally crucial unsaturated fatty acids, especially rich in high omega-3 bonds, are very prone to oxidation. This phenomenon makes oxidation stability a substantial challenge in every formulation, especially those which contain or at some stage of preparation contain water. Bigels and emulgels, which represent promising structured lipid systems for replacing saturated and trans fats in food formulations, pose significant oxidative stability challenges. This review examines oxidation mechanisms in such biphasic systems. Oxidation in bigels and emulgels proceeds through both free-radical-mediated autoxidation and metal-ion-catalysed pathways, with the oil–water interface serving as the primary reaction zone where pro-oxidants concentrate, and lipid substrates become accessible. Structural configuration critically determines oxidative stability, following the sequence W/O bigel > bicontinuous bigel > O/W bigel. The high viscosity of gel matrices provides substantial protection by restricting radical mobility and oxygen diffusion. Mass transfer occurs via diffusion, collision–exchange–separation, and micelle-assisted mechanisms, with association colloids forming localized interfaces that accelerate oxidation. Thermal processing presents particular challenges, as temperatures above 50 °C disrupt most gel structures and accelerate oxidative degradation. Effective protective strategies include interfacial engineering with emulsifiers to reduce oil–water interfacial tension, incorporation of natural antioxidants (e.g., phenolic compounds and tocopherols), and synergistic antioxidant combinations. This review provides a mechanistic framework for formulating oxidatively stable bigels and emulgels suitable for food applications. Full article

Hydrogen production via water electrolysis using desalinated seawater offers a sustainable energy solution and has attracted considerable attention in recent years. However, its efficiency depends heavily on the quality of water. Many studies have not explored the relationship between treated water quality and hydrogen generation efficiency at each stage of the seawater desalination process. This study examines a three-step seawater desalination process comprising softening with ballasted flocculation (SBF) as a pretreatment, reverse osmosis (RO) as the main desalination step, and ion exchange as a polishing step to provide high-quality water for electrolysis. Water from each purification stage was supplied to the electrolyzer to compare the impact on water quality and hydrogen generation efficiency. The SBF process removed magnesium (Mg) and calcium (Ca) from seawater, as well as turbidity and bacteria, but hydrogen production via water electrolysis continued for no more than 10 h. However, when feeding RO water and RO water processed by ion exchange after the SBF process, hydrogen was generated stably and continuously for 70 h, achieving high efficiency comparable to that of commercial pure water. High production of green hydrogen by water electrolysis is possible through RO seawater desalination combined with SBF pretreatment. Full article

The accelerating transition to low carbon energy systems has intensified the demand for nickel and cobalt from low-grade (<1.5 wt.%) refractory lateritic ores. These low-grade laterites are however not amenable to conventional beneficiation due to their complex mineralogy, eclectic physicochemical properties, and fine Ni–Co dissemination. This review examines recent advances made in the extraction of nickel and cobalt from complex low-grade lateritic ores, emphasizing the interplay between ore mineralogy, chemistry, beneficiation, pretreatment, and processing route selection. Developments in selective ore comminution–classification have led to the generation of Ni-rich fine fractions (undersize) and Co-rich coarse fractions (oversize), enabling differentiated extraction strategies that improve resource utilization, frugal energy use, and process efficiency. Mechanical activation via stirred media milling, thermal calcination-induced structural disorder, and dehydroxylate goethite products, are shown to significantly enhance Ni–Co leaching kinetics under both atmospheric and heap leaching conditions. A critical comparison of pyrometallurgical (rotary-kiln electric furnace) and hydrometallurgical (HPAL, EPAL, heap, atmospheric, bioleaching) routes demonstrates that ore-specific optimization is essential to balance recovery, acid consumption, and greenhouse gas emissions. The novel resin in moist mix (RIMM) process, which integrates ambient leaching and in situ ion exchange selective recovery, is shown to offer potential for sustainable values extraction from sub-economic resources. Furthermore, the review highlights the key innovation challenges and concomitant opportunities for enhanced critical battery metal recovery from complex laterite ores. Full article

5-aminolevulinic acid (5-ALA) affords various positive health effects, including benefits for conditions such as diabetes. Biological fermentation holds potential for efficiently mass-producing biomolecules, including 5-ALA, yet it generally results in a mixture of target molecules and impurities, including byproducts. Pyrazine-2,5-dipropionic acid (PY), a dimer of 5-ALA, can easily form in 5-ALA production and is one of its major impurities. In this study, we developed an integrated purification process for 5-aminolevulinic acid phosphate (5-ALAP) produced via biological fermentation. The process consists of 16 stages, including impurity removal (ion-exchange resins) and crystallization. Three types of ion-exchange resin (IER) columns were combined to remove impurities such as byproducts and pigment. Comprehensive condition setting for crystallization was carried out to reduce the amount of residual poor solvent in the 5-ALAP crystals. The obtained crystals contained significantly fewer impurities (<0.05% vs. 5-ALAP), such as PY, compared with their commercially available counterparts. The residual poor solvent in the 5-ALAP crystals was reduced to below 1000 ppm under the crystallization conditions. We confirmed the high scalability of the purification method developed in this study. Therefore, this article provides an industrially applicable purification process for fermentatively produced 5-ALA. Full article

Recovery of scandium from chloride-bearing process liquors formed during titanium–magnesium production remains constrained by trace-level metal content and chemically aggressive solution matrices. Within the present study, the retention behaviour of Sc³⁺ species in strongly acidic chloride media was examined through batch-mode interaction with gel-type sulfonated cation exchangers, namely KU-2-8, Lewatit SP112H, Purosorb SAC140H, and Purolite C-150H. Quantitative evaluation of sorption efficiency was performed by calculating equilibrium uptake (q_e), phase distribution factor (K_d), and percentage recovery (R). Under identical liquid–solid ratios, the Lewatit SP112H matrix exhibited superior affinity toward dissolved scandium, achieving q_e = 179.82 mg/g and K_d = 172.41 mL/g. Equilibrium fitting procedures revealed that scandium uptake by Purosorb SAC140H conforms to monolayer-type retention described by the Langmuir formalism (R² = 0.9786), whereas sorption on Lewatit SP112H proceeds over energetically non-uniform sites and is more adequately represented by Freundlich and Dubinin–Radushkevich approximations. The observed retention characteristics establish a selection framework for ion-exchange media applicable to scandium concentration from acidic chloride hydrometallurgical streams. Full article

The rapid increase in end-of-life lithium-ion batteries demands sustainable recycling routes for lithium recovery. This work presents a novel integrated hydrometallurgical–electrodialysis process designed specifically for recovering lithium from off-specification NMC cathode materials while enabling full reagent recyclability. Selective leaching with oxalic acid was optimised by setting the water-to-oxalic acid dihydrate ratio (H₂O/OA·2H₂O) to 7.3:1 w/w, achieving 81% lithium extraction at room temperature within 2 h while limiting the co-dissolution of Ni, Co and Mn to 0.2%, 1.6% and 1.7% by weight, respectively. The resulting leachate was processed in a four-chamber electrodialysis cell equipped with two Nafion 117 cation-exchange membranes and one Neosepta AMX-fmg anion-exchange membrane operating at −1.6 V versus Ag/AgCl, enabling 96% lithium recovery and 98% oxalic acid recovery. The regenerated oxalic acid stream (41.8 g L⁻¹) was fully restored to its initial concentration and reused in successive cycles without performance loss. Subsequent precipitation of lithium with Na₂CO₃ yielded 99.3%-pure Li₂CO₃. This combined leaching–electrodialysis–precipitation presents a high selectivity, low-waste, circular recovery system, offering a scientifically original approach that integrates reagent regeneration with high-purity lithium production. Full article

Analyzing the hydrochemical characteristics and formation mechanism of metasilicic acid (H₂SiO₃) enrichment in the groundwater of Sanjiang Plain is conducive to guiding the rational development and utilization of mineral water resources in this region. Taking the groundwater in the typical black soil area of the northeastern Sanjiang Plain (from Qindeli Farm to Chuangye Farm) as an example, 104 groups of groundwater samples were collected to analyze enrichment and controlling factors of H₂SiO₃ by comprehensive methods such as hydrochemical analysis, rock geochemistry, water–rock interaction analysis, and ion ratio analysis. The results showed that the groundwater was generally in a reducing environment with low mineralization and weak acidity. The main cations were Ca²⁺ and Mg²⁺, and the main anion was HCO₃⁻. The hydrochemical types were mainly HCO₃–Ca and HCO₃–Ca·Mg, followed by HCO₃·Cl–Ca·Mg mixed type, and the H₂SiO₃ enrichment rate of groundwater reached 80.77%. The enrichment of H₂SiO₃ in the groundwater was related to the local geological structure and specific hydrogeochemical processes, and mainly controlled by the hydrolysis process of silicate rock minerals (such as albite, plagioclase, and olivine). The silicates and aluminosilicates contained in the basalt, diorite, and gneiss distributed in the area provided a rich material basis for the enrichment of H₂SiO₃. Its migration and distribution were simultaneously affected by leaching and cation exchange, while NO₃⁻ and SO₄²⁻ input from anthropogenic sources also participated in the rock weathering, specifically the enrichment process of H₂SiO₃ in the groundwater. From the perspective of mineralization conditions, Qinglongshan Farm and Qindeli Farm are potential areas for developing H₂SiO₃-rich mineral water. However, the main direction for the development and utilization of groundwater in this area should be to explore natural H₂SiO₃-rich groundwater with good comprehensive water quality. Full article

Maintaining a membrane electrical potential of biological cells is a dynamic process, as some cells have a continually changing potential, like pacemaker cells, while other cells may function with large or small changes in the membrane potential. Additionally, some cells may change their electrical potential when stimulated or inhibited by electrical signals, chemical compounds, or both—either simultaneously or episodically. The persistent leak of K⁺ through two-pore-domain potassium channels (K2P) and of Na⁺ through Na⁺ leak channels (NALCNs) and the action of pumps and exchangers are primarily responsible for maintaining a resting potential. Ca²⁺ ions are known to block the NALCNs and result in a more hyperpolarized membrane potential, with a reduction in Ca²⁺ resulting in a depolarized state. Using the larval muscles of Drosophila, the membrane potentials were monitored as Ca²⁺ and Mg²⁺ concentrations were altered. Changes as large as 20 mM of Mg²⁺ had only small effects (1 to 2 mV) on the membrane potential compared to 3–5 mM changes in Ca²⁺ having larger effects (5–10 mV). Although, it appears raised [Mg²⁺] may dampen the changes induced by Ca²⁺. Simulations of the G-H-K equation estimate the changes in permeability of Na+ (pNa). These experiments are significant, as the clinical severity of hypocalcemia and hypercalcemia may also depend on Mg²⁺ levels. Full article

Candidozyma (Candida) auris is a fungal pathogen associated with life-threatening invasive infections and high mortality rates. It is becoming a major global public health concern due to its ability to resist multiple antifungal drugs and spread in healthcare settings. Despite this, little is known about the mechanisms underlying drug resistance, fungal development, pathogenesis, and virulence. Among the factors contributing to these processes, transporters play a central role in fungal biology, regulating nutrient acquisition, metabolite exchange, ion homeostasis, and drug efflux. However, the composition and diversity of transporter systems in C. auris remain poorly defined. Through genomic analysis, we identified 686 transporters and 125 accessory factors involved in transport in C. auris, most of which had not been characterized. These transporters and accessory factors were classified into seven classes, 22 subclasses, and 215 families, reflecting substantial functional diversity. Comparative analyses with other pathogenic Candida species and Saccharomyces cerevisiae reveal lineage-specific divergence in several transporter families. We also integrated multiple publicly available RNA-seq datasets encompassing antifungal drug exposure and drug-resistant isolates and identified subsets of transporters that are transcriptionally responsive in distinct antifungal conditions, including members of families implicated in drug transport, metabolism, and ion homeostasis. Together, this study defines the landscape of transporter systems in C. auris and highlights transporter families that may contribute to stress adaptation and antifungal responses, providing a resource for future functional and mechanistic investigations. Full article

The industrial application of modified ion-exchange membranes is limited by complex, discontinuous ex-situ processes. This study introduces an in-situ electro-assembly strategy that enables the direct fabrication of a selective layer within an electrodialysis stack without disassembly. By utilizing a programmed current reversal to orchestrate the sequential deposition of polyethyleneimine (PEI), glutaraldehyde cross-linking, and polystyrene sulfonate (PSS) adsorption, we achieve meticulous interfacial engineering on a commercial cation exchange membrane. Comprehensive characterization confirms the successful construction of a hydrophilic, charge-tuned multilayer, which enhances ion transport kinetics and raises the limiting current density. This method culminates in a membrane with an exceptional Li⁺/Mg²⁺ selectivity of 107.9 and robust stability, retaining a significant selectivity of 47 over 10 cycles in real salt lake brine. This synergistic integration of operational simplicity, interfacial precision, and superior performance establishes a transformative and scalable platform for manufacturing high-performance membranes for selective ion separation from complex brine sources. Full article

In this study, the catalytic potential of peroxidase enzymes obtained from soybean industrial residues was investigated for the decolorization of the azo dye Direct Blue 2 (DB2) in textile wastewater. Peroxidase fractions (15 ± 5 U/L) were extracted and partially purified by ion-exchange chromatography and applied to a pilot-scale effluent, achieving DB2 degradation rates of 1.48 mg/L·h in the presence of chemical additives. High-performance liquid chromatography confirmed dye removal and detected benzidine (1 mg/L) as a degradation byproduct. Acute toxicity tests using Vibrio fischeri showed minimal variation, with values of 8 TU for untreated wastewater and 7.94 TU after enzymatic treatment. A subsequent Fenton process was implemented as a polishing step, achieving up to 90% decolorization, a 30% reduction in organic matter, and complete elimination of toxicity at an FeSO₄/H₂O₂ ratio of 1:2.4. The results demonstrate a sustainable strategy for pre-treating textile effluents containing azo dyes through the enzyme-based valorization of agro-industrial residues. Full article