Search Results (205)

Elevated phosphorus levels in wastewater created significant environmental concerns, including the degradation of surrounding soil structure, inhibition of plant growth, and potential threats to human health. To address this issue, a self-standing nanofibrous composite membrane based on PA-66/PVA-15%La(OH)₃ was fabricated via electrospinning, followed by glutaraldehyde (GA) crosslinking and alkali hydrolysis to create an interpenetrating structure, where PA-66 provided the overall mechanical strength of the membrane, while La served as a functional component for the adsorption of phosphate. The chemical composition, surface morphology, thermal stability, and mechanical properties of the resulting membranes were characterized using ATR-FTIR, SEM, TGA, and tensile testing, respectively. Furthermore, the adsorption performance of the membranes was evaluated systematically through static and dynamic adsorption. The Langmuir isotherm model yielded a theoretical maximum adsorption capacity of 21.39 mg/g for phosphate ions. Notably, over 96% of this capacity was retained even in the presence of interfering ions. Moreover, dynamic adsorption experiments demonstrated that the membrane can deal with 1.74 L of phosphate-containing wastewater at a low flow rate of 1.0 mL/min and 1.46 L at a high flow rate of 2.0 mL/min, respectively, while consistently maintaining a phosphate removal efficiency exceeding 90%. A controlled release of phosphate ions from a phosphate-adsorbed membrane was successfully demonstrated using Mougeotia cultivation, implying the potential for phosphorus resource recovery. Full article

For the precise description of gas physical processes in high-voltage direct current (HVDC) transmission, an advanced and robust numerical framework for the simulation of transient particle densities in the course of corona discharges is developed in this work. The aim is the scalable and consistent modeling of the space charge density under realistic conditions. The core component of the framework is a discontinuous Galerkin method that ensures the conservative properties of the underlying hyperbolic problem. The space charge density at the electrode surface is imposed as a dynamic boundary condition via Lagrange multipliers. To increase the numerical stability and convergence rate, a homotopy approach is also integrated. For the experimental validation, a measurement concept was realised that uses a subtraction method to specifically remove the displacement current component in the signal and thus enables an isolated recording of the transient ion current with superimposed voltage stresses. The experimental results on a small scale agree with the numerical predictions and prove the quality of the model. On this basis, the framework is transferred to hybrid HVDC overhead line systems with a bipolar design. In the event of a fault, significant transient space charge densities can be seen there, especially when superimposed with new types of voltage waveforms. The framework thus provides a reliable contribution to insulation coordination in complex HVDC systems and enables the realistic analysis of electrohydrodynamic coupling effects on an industrial scale. Full article

Oil and gas field water not only contains low concentrations of lithium but also a lot of suspended matter, inorganic salt, and organic matter. Both inorganic ions and organic substances influence the extraction of lithium. To improve the extraction efficiency of low-concentration lithium in oil and gas field water, the effects of Na⁺, K⁺, Ca²⁺, Mg²⁺, Cl⁻, Br⁻, SO₄²⁻, NO₃⁻, and organic substances on the extraction efficiency of lithium were studied. The results showed that Na⁺ can promote the extraction of lithium to a certain extent, and lithium ions competed with K+ for extraction; however, the separation coefficient remained more than 13. Ca²⁺ and Mg²⁺ have a significant influence on the extraction of lithium and should be removed prior to extraction. Cl⁻, SO₄²⁻, and NO₃⁻ have little influence on the extraction solution of lithium. Among the organic components, a high concentration of long-chain alkane has a certain effect on the extraction efficiency of lithium, while other substances have little effect. On this basis, the first step for precipitating impurity ions and the second step for solvent extraction of lithium were established. After removing the impurity ions, the extraction efficiency of lithium can reach over 90%. Taking 15L of oil and gas field water as the research object, after extraction, back extraction, concentration, depth impurities removal by extraction, and precipitation drying, the purity of the lithium carbonate product can be achieved at 99.28%. This study can provide technical support for the efficient extraction of low-concentration lithium from oil and gas field water. Full article

The treatment of contaminants from road infrastructure poses significant challenges due to their variable composition and the high concentrations of chloride ions, heavy metals, and oil-derived substances. Traditional methods for protecting groundwater environments are often insufficient. A promising alternative is permeable reactive barrier (PRB) technology, which utilizes recycled materials and construction waste as reactive components within the treatment zone of the ground. This paper delves into the potential of employing a composite (MIX) consisting of modified construction aggregate (as recycled material) and activated carbon (example of reactive material) to address environmental contamination from a mixture of heavy metals and chloride. The research involved chemical modifications of the road aggregate, activated carbon, and their composite, followed by laboratory tests in glass reactors and non-flow batch tests to evaluate the kinetics and chemical equilibrium of the reactions. The adsorption process was stable and conformed to the pseudo-second-order kinetics and Langmuir, Toth, and Redlich–Peterson isotherm models. Studies using MIX from a heavy metal model solution showed that monolayer adsorption was a key mechanism for removing heavy metals, with strong fits to the Langmuir (R² > 0.80) and Freundlich models, and optimal efficiencies for Cd and Ni (R² > 0.90). The best fit, at Cd, Cu, Ni = 0.96, however, was with the Redlich–Peterson isotherm, indicating a mix of physical and chemical adsorption on heterogeneous surfaces. The Toth model was significant for all analytes, fitting Cl and Cd well and Pb and Zn moderately. The modifications made to the composite significantly enhanced its effectiveness in removing the contaminant mixture. The test results demonstrated an average reduction of chloride by 85%, along with substantial removals of heavy metals: lead (Pb) by 90%, cadmium (Cd) by 86%, nickel (Ni) by 85%, copper (Cu) by 81%, and zinc (Zn) by 79%. Further research should focus on the removal of other contaminants and the optimization of magnesium oxide (MgO) dosage. Full article

Chemically demethoxylated and Ca-cross-linked orange-peel waste was engineered as a biosorbent for Mn(II) removal from water. A three-factor Box–Behnken design (biosorbent dose 3–10 g L⁻¹, initial Mn²⁺ 100–300 mg L⁻¹, contact time 3–8 h; pH 5.5 ± 0.1, 25 °C) required only 16 runs to locate the optimum (10 g L⁻¹, 100 mg L⁻¹, 8 h), at which the material removed 94.8% ± 0.3% manganese removal under the optimized conditions (10 g L⁻¹, 100 mg L⁻¹, 8 h, pH 5.5) of dissolved manganese and reached a Langmuir capacity of 29.7 mg g⁻¹. Equilibrium data fitted the Freundlich (R² = 0.968) and Sips (R² = 0.969) models best, indicating a heterogeneous surface, whereas kinetic screening confirmed equilibrium within 6 h. FTIR and SEM–EDX verified abundant surface –COO⁻/–OH groups and showed Mn deposits that partially replaced residual Ca, supporting an ion-exchange component in the uptake mechanism. A preliminary cost analysis (<USD 10 kg⁻¹) and > 90% regeneration efficiency over three cycles highlight the economic and environmental promise of this modified agro-waste for polishing Mn-laden effluents. Full article

This study theoretically investigates the potential of a polyacrylamide copolymerized with amylose, a primary component of starch, to evaluate its efficiency in removing heavy metals from industrial wastewater. This material concept seeks to combine the high adsorption capacity of polyacrylamide with the low cost and biodegradability of starch, ultimately aiming to offer an economical, efficient, and sustainable alternative for wastewater treatment. To this end, a computational model based on density functional theory (DFT) was developed, utilizing the B3LYP functional with the 6-311++G(d,p) basis set, a widely recognized combination that strikes a balance between accuracy and computational cost. The interactions between an acrylamide-amylose (AM/Amy) polymer matrix, as well as the individual polymers (AM and Amy), and the metal ions Pb, Hg, and Cd in their hexahydrated form (M·6H₂O) were analyzed. This modeling approach, where M represents any of these metals, simulates a realistic aqueous environment around the metal ion. Molecular geometries were optimized, and key parameters such as total energy, dipole moment, frontier molecular orbital (HOMO-LUMO) energy levels, and Density of States (DOS) graphs were calculated to characterize the stability and electronic reactivity of the molecules. The results indicate that this proposed copolymer, through its favorable electronic properties, exhibits a high adsorption capacity for metal ions such as Pb and Cd, positioning it as a promising material for environmental applications. Full article

In this study, we report the synthesis and characterization of a novel NH₂-MIL-101(Fe) magnetic composite, developed via in situ formation of NH₂-MIL-101(Fe) in the presence of Fe₃O₄ nanoparticles embedded within a chloropropyl-modified mesoporous silica layer. This hybrid composite retains the high adsorption capacity of NH₂-MIL-101(Fe) while benefiting from the easy magnetic separation enabled by Fe₃O₄ nanoparticles. The mesoporous silica forms a protective porous coating around the magnetic nanoparticles, significantly enhancing its chemical stability and preventing clumping. Beyond protection, the mesoporous silica layer provides a high-surface-area scaffold that promotes the uniform in situ growth of NH₂-MIL-101(Fe). Functionalization of the silica surface with chloride groups enables strong electrostatic interactions between the magnetic component and metal organic framework (MOF), ensuring a homogeneous and stable hybrid structure. The new composite’s capacity to remove Pb(II) and Cd(II) ions from aqueous solutions was systematically investigated. The adsorption data showed a good fit with the Langmuir isotherm model for both ions, the maximum adsorption capacities calculated being 214.6 mg g⁻¹ for Pb(II) and 181.6 mg g⁻¹ Cd(II). Furthermore, the kinetic behavior of the adsorption process was accurately described by the pseudo-second-order model. These findings confirm the effectiveness of this composite for the removal of Pb(II) and Cd(II) ions from aqueous solutions, demonstrating its potential as an efficient material for environmental remediation. The combination of magnetic recovery, high adsorption capacity, and stability makes this novel composite a promising candidate for heavy metal removal applications in water treatment processes. Full article

The conventional spent lithium-ion batteries (LIBs) recycling method suffers from complex processes and excessive chemical consumption. Hence, this study proposes an electrochemical strategy for achieving reductant-free leaching of high-valence transition metals and efficient separation of valuable components from spent cathode sheets (CSs). An innovatively designed sandwich-structured electrochemical reactor achieved efficient reductive dissolution of cathode materials (CMs) while maintaining the structural integrity of aluminum (Al) foils in a dilute sulfuric acid system. Optimized current enabled leaching efficiencies exceeding 93% for lithium (Li), cobalt (Co), manganese (Mn), and nickel (Ni), with 88% metallic Al foil recovery via cathodic protection. Multi-scale characterization systematically elucidated metal valence evolution and interfacial reaction mechanisms, validating the technology’s tripartite innovation: simultaneous high metal extraction efficiency, high value-added Al foil recovery, and organic removal through single-step electrochemical treatment. The process synergized the dissolution of CM particles and hydrogen bubble-induced physical liberation to achieve clean separation of polyvinylidene difluoride (PVDF) and carbon black (CB) layers from Al foil substrates. This method eliminates crushing pretreatment, high-temperature reduction, and any other reductant consumption, establishing an environmentally friendly and efficient method of comprehensive recycling of battery materials. Full article

Semiconductor device fabrication is conducted through highly precise manufacturing processes. An essential component of the semiconductor package is the lead frame on which the silicon dies are assembled. Impurities such as oxides or organic matter on the surfaces have an impact on the process yield. Plasma cleaning is a vital process in semiconductor manufacturing, employed to enhance production yield through precise and efficient surface preparation essential for device fabrication. This paper explores the various facets of plasma cleaning, with a particular emphasis on its application in the cleaning of lead frames used in semiconductor packaging. To provide comprehensive context, this paper also reviews the critical role of plasma in advanced and emerging packaging technologies. This study investigates the fundamental physics governing plasma generation, the design of plasma systems, and the composition of the plasma medium. A central focus of this work is the comparative analysis of different plasma systems in terms of their effectiveness in removing organic contaminants and oxide residues from substrate surfaces. By utilizing reactive species generated within the plasma—such as oxygen radicals, hydrogen ions, and other chemically active constituents—these systems enable a non-contact, damage-free cleaning method that offers significant advantages over conventional wet chemical processes. Additionally, the role of non-reactive species, such as argon, in sputtering processes for surface preparation is examined. Sputtering is the ejection of individual atoms from a target surface due to momentum transfer from an energetic particle (usually an ion). Sputtering is therefore a physical process driven by momentum transfer. Energetic ions, such as argon (Ar⁺), are accelerated from the plasma to bombard a target surface. Upon impact, these ions transfer sufficient kinetic energy to atoms within the material’s lattice to overcome their surface binding energy, resulting in their physical ejection. This paper also provides a comparative assessment of various plasma sources, including direct current, dielectric barrier discharge, radio frequency, and microwave-based systems, evaluating their suitability and efficiency for lead frame cleaning applications. Furthermore, it addresses critical parameters affecting plasma cleaning performance, such as gas chemistry, power input, pressure regulation, and substrate handling techniques. The ultimate aim of this paper is to provide a concise yet comprehensive resource that equips technical personnel with the essential knowledge required to make informed decisions regarding plasma cleaning technologies and their implementation in semiconductor manufacturing. This paper provides various tables which provide the reader with comparative assessments of the various plasma sources and gases used. Scoring mechanisms are also introduced and utilized in this paper. The scores achieved by both the sources and the plasma gases are then summarized in this paper’s conclusions. Full article

In this study, liquid chromatography–mass spectrometry (LC-MS) was employed to conduct untargeted metabolomics analysis on black rice (BR), milled black rice (MBR), wet germinated black rice (WBR), and high-temperature and high-pressure-treated WBR (HTP-WBR). A total of 6988 positive ions and 7099 negative ions (multiple difference ≥1.2 or ≤0.8333, p < 0.05, and variable importance in projection ≥1) were isolated, and 98 and 100 differential metabolic pathways were identified between the different samples in the positive and negative ion modes, respectively. Distinctive variations in the metabolic compositions of BR, MBR, WBR, and HTP-WBR were observed. Flavonoids, fatty acids, lipids, phenylpropanoids, polyketides, benzenoids, and organooxygen were the dominant differential metabolites. Milling removed the majority of bran-associated bioactive components such as phenolic acids, anthocyanins, micronutrients, fatty acids, antioxidants, and dietary fiber. The germination process significantly reduced the number of flavonoids, polyketides, and lipid-related metabolites, while enzymatic activation notably increased the number of organic acids and amino acids. HTP treatment synergistically enhanced the content of heat-stable flavonoids and polyketides, while simultaneously promoting fatty acid β-oxidation. These findings establish novel theoretical foundations for optimizing processing methodologies and advancing functional characterization in black rice product development. Full article

Excessive phosphorus discharge from fertilizers and detergents has caused severe eutrophication in water bodies, necessitating the upgrading of efficient and cost-effective adsorbents for phosphorus removal. In this study, a novel lanthanum and extracellular polymeric substance (EPS) coprecipitation-modified ceramic (La-EPS-C-450) was developed to address the limitations of existing adsorbents. The ceramic filler served as a robust and scalable matrix for lanthanum loading, while EPS introduced functional groups and carbonate components that enhanced adsorption efficiency. The prepared adsorbent manifested a maximum phosphorus adsorption capacity of 83.5 mg P/g-La at 25 °C, with its performance well expressed by the Freundlich isotherm model, indicating that it was a multilayer adsorption process. The adsorption mechanism was driven by electrostatic attraction and ligand exchange between lanthanum and phosphate ions, forming inner-sphere complexes. The material demonstrated unfluctuating‌ performance across a pH range of 3–7 and retained high selectivity in the presence of competing anions. In practical applications, La-EPS-C-450 effectively removed phosphorus from actual river water, achieving a treatment capacity of 1800 bed volumes in a continuous-flow fixed column system. This work provides valuable insights into the progress of advanced ceramic-based adsorbents and demonstrates the potential of La-EPS-C-450 as a cost-efficient and effective material for phosphorus removal in water treatment applications. Full article

Heavy metal contamination of water is a critical environmental problem due to its toxicity and persistence in ecosystems. In this study, magnetic hydrogel spheres composed of carboxymethylated starch modified with poly(1-vinylimidazole) (CMS-g-PVI) and polyvinyl alcohol (PVA), combined with Fe₃O₄ nanoparticles, were synthesized and characterized to evaluate their efficiency in adsorbing metal ions such as Cu²⁺, Pb²⁺, and Cd²⁺. Structural characterization by FT-IR spectroscopy confirmed the successful integration of all functional components into the hydrogel matrix. Additionally, scanning electron microscopy (SEM) revealed a rough and porous surface morphology favorable for adsorption and an average bead diameter of 3.2 mm, influenced by the stirring rate during synthesis. Adsorption studies demonstrated maximum capacities of 82.4 mg·g⁻¹ for Cu²⁺, 66.5 mg·g⁻¹ for Pb²⁺, and 51.8 mg·g⁻¹ for Cd²⁺, with optimal removal efficiencies at pH 6.2 and 5.7. From a theoretical perspective, density functional theory (DFT) calculations using the B3LYP/6-311+G(d,p) method allowed the optimization of molecular structures and analysis of electronic properties. The total dipole moment (TDM) of the CMS-g-PVI/PVA system reached 20.81 Debye. A significant reduction in the HOMO-LUMO energy gap was observed upon metal adsorption, with values of 0.0308 eV for Cu²⁺, 0.0175 eV for Pb²⁺, and 0.0235 eV for Cd²⁺, confirming strong interactions between the hydrogel matrix and the metal ions. The combined experimental and computational approach provides a comprehensive understanding of the adsorption mechanisms and supports the development of efficient materials for water decontamination. Full article

Based on the characteristics and effective components of steel slag and desulfurization gypsum, a new type of permeable reactive material was prepared by combining steel slag and desulfurization gypsum, and a simulation experiment of arsenic- and antimony-contaminated groundwater remediation was carried out. A combination of X-ray fluorescent, BGRIMM Process Mineralogy Analyzing System (BPMA), ICP-MS, and SEM-EDS detection and analysis methods was used to investigate the effects of steel slag particle size, desulfurization gypsum particle size, steel slag and desulfurization gypsum ratio, and steel slag-desulfurization gypsum mixed test block particle size on the performance of the permeable reactive wall to remove arsenic and antimony. The results show that a permeable reactive wall composed of steel slag (−4.75 + 1.18 mm) and desulfurization gypsum (−13.2 + 9.5 mm) in a 4:1 ratio achieved removal rates of 91.85% for As and 90.58% for Sb, reducing their concentrations below the drinking water standard. The purpose of using steel slag and desulfurization gypsum to intercept heavy metals and toxic ions in surface runoff was achieved. Arsenic was adsorbed, physically encapsulated, and lattice solidified by C-S-H gel. This research provides a cost-effective and environmentally friendly solution for the storage of steel slag and desulfurization gypsum while addressing heavy metal pollution in groundwater. Full article

To fulfil the goals of the circular economy, the treatment of textile wastewater should be focused on the recovery of valuable components. Monovalent anion-selective electrodialysis (MASED) was applied for the separation of reactive dyes from mineral salts. Standard cation-exchange membranes (CM membranes) and monovalent selective anion-exchange membranes (MVA membranes) were used in the electrodialysis (ED) stack. The separation efficiency was evaluated for model solutions of various reactive dyes (varying in molecular weight and chemical reactivity) containing NaCl. In the course of MASED, the mineral salt was successfully removed from the dye solutions with an efficacy of 97.4–99.4%, irrespectively of the composition of the treated solution. The transport of dye molecules through the ion-exchange membranes (IEMs) from diluate to concentrate compartments was irrelevant. Nonetheless, a significant adsorption of dye particles on the membranes was observed. Around 11–40% of the initial dye mass was deposited in the ED stack. Dye adsorption intensity was significantly affected by dye reactivity. This study showed the potential of the MASED process for the separation of the reactive dye from the mineral salt on condition that antifouling membrane properties are improved. The obtained streams (the concentrate rich in mineral salt and the diluate containing the reactive dye) can be reused in the dye-house textile operations; however, some loss of dye mass should be included. Full article

Rare earth elements, comprising 17 elements including 15 lanthanides, are essential components in numerous high-tech applications. While physicochemical methods are commonly employed to remove toxic heavy metals (e.g., cadmium and mercury) from industrial wastewater, biological approaches offer increasingly attractive alternatives. Biomining, which utilizes microorganisms to extract valuable metals from ores and industrial wastes, and bioremediation, which leverages microorganisms to adsorb and transport metal ions into cells via active transport, provide eco-friendly solutions for resource recovery and environmental remediation. In this study, we investigated the potential of three recently identified lanthanide-binding proteins—SPL2, lanpepsy, and lanmodulin—for applications in these areas using single-cell inductively coupled plasma mass spectrometry (scICP-MS). Our results demonstrate that SPL2 exhibits superior characteristics for lanthanide and cadmium bioremediation. Heterologous expression of a cytosolic fragment of SPL2 in bacteria resulted in high expression levels and solubility. Single-cell ICP-MS analysis revealed that these recombinant bacteria accumulated lanthanum, cobalt, nickel, and cadmium, effectively sequestering lanthanum and cadmium from the culture media. Furthermore, SPL2 expression conferred enhanced bacterial tolerance to cadmium exposure. These findings establish SPL2 as a promising candidate for developing recombinant bacterial systems for heavy metal bioremediation and rare earth element biomining. Full article