Search Results (968)

Thermodynamic factors (supersaturation of substances that form crystals) and kinetic factors (heterogeneous nucleants and crystallization inhibitors) affect the formation of crystals and stones in the urinary tract. We studied the effect of five different polyhydroxycarboxylic acids and phytate on the formation of calcium oxalate crystals in artificial urine. All tested molecules are known to inhibit the crystallization of this calcium salt, and to also form complexes with calcium ions. Considering the typical concentration of polyhydroxycarboxylic acids in urine (similar to that of the calcium ion) and their ability to inhibit crystallization, their most important effect is the capacity to complex calcium—a thermodynamic effect. For phytate and its metabolites, which are present in concentrations much lower than that of the calcium ion, the most important effect is as a crystallization inhibitor—a kinetic effect. Among the five polyhydroxycarboxylic acids examined here, hydroxycitrate had the strongest complexing capacity, and the addition of phytate to hydroxycitrate led to greater inhibition of crystallization. Therefore, because oral consumption of hydroxycitrate does not increase the urinary pH, it is likely that the combined consumption of hydroxycitrate and phytate can provide certain benefits for patients with increased risk of developing calcium oxalate stones. We also discussed the effects of these different molecules on the different calcium oxalate stones, including papillary calcium oxalate monohydrate stones, cavity calcium oxalate monohydrate stones, calcium oxalate dihydrate stones, and mixed calcium oxalate dihydrate/hydroxyapatite stones. Full article

Background: With the increasing shift in drug design away from classical drug targets towards the modulation of protein-protein interactions, synthetic peptides are gaining increasing relevance. The synthesis and purification of peptides via solid-phase peptide synthesis (SPPS) strongly rely on trifluoroacetic acid (TFA) as a cleavage agent and ion-pairing reagent, respectively, resulting in peptides being obtained as TFA salts. Although TFA has excellent properties for peptide production, numerous studies highlight the negative impact of using peptides from TFA⁻ salts in biological assays. Methods: Investigated peptides were synthesized via SPPS and the TFA⁻ counterion was exchanged for Cl⁻ via freeze-drying in different concentrations of HCl. Detection and quantification of residual TFA⁻ were carried out via FT-IR, ¹⁹F-NMR, and HPLC using an evaporative light-scattering detector (ELSD). A liposomal fluorescence assay was used to test for the influence of the counterion on the peptides’ passive membrane permeability. Results: All TFA⁻ detection methods were successfully validated according to ICH guidelines. TFA⁻ removal with 10 mM HCl was determined to be the optimal condition. No impact on peptide purity was observed at all HCl concentrations. Influences on permeability coefficients depending on peptide sequence and salt form were found. Conclusions: This study presents a systematic investigation of the removal of TFA⁻ counterions from synthetic peptides and their replacement with Cl⁻ counterions. Detected counterion contents were used to understand the impact of sequence differences, especially positive charges, on the amount and potential localization of counterions. Our findings emphasize the importance of counterion quantification and specification in assays with synthetic peptides. Full article

To address freshwater scarcity and the underutilization of low-saline water in the North China Plain, a field study was conducted to evaluate the effects of alternating sprinkler irrigation using saline and fresh water on soil water–salt dynamics and corn growth. Two salinity levels (3 and 5 g·L⁻¹, representing S1 and S2, respectively) and three irrigation strategies—saline–fresh–saline–fresh (F1), saline–fresh (F2), and mixed saline–fresh (F3)—were tested, resulting in six treatments: S1F1, S1F2, S1F3, S2F1, S2F2, and S2F3. S1F1 significantly improved soil water retention at a 30–50 cm depth and reduced surface electrical conductivity (EC) and Na⁺ concentration (p < 0.05). S1F1 also promoted more uniform Mg²⁺ distribution and limited Ca²⁺ loss. Under high salinity (5 g·L⁻¹), surface salt accumulation and ion concentration (Na⁺, Mg²⁺, and Ca²⁺) increased, particularly in S2F3. Corn growth under alternating irrigation (F1/F2) outperformed the mixed mode (F3), with S1F1 achieving the highest plant height, leaf area, grain number, and 100-grain weight. The S1F1 yield surpassed others by 0.4–3.0% and maintained a better ion balance. These results suggest that alternating irrigation with low-salinity water (S1F1) effectively regulates root-zone salinity and improves crop productivity, offering a practical strategy for the sustainable use of low-saline water resources. Full article

The salt flotation of graphite in the presence of lithium nickel manganese cobalt oxide (NMC) was assessed by performing colloidal probe atomic force microscopy (CP-AFM) on sessile gas bubbles and conducting batch flotation tests with model lithium-ion-battery black mass. The modeling of film drainage and detachment during particle–bubble interactions provides insight into the fundamental microprocesses during salt flotation, a special variant of froth flotation. The interfacial properties of particles and gas bubbles were tailored with salt solutions containing sodium chloride and sodium acetate buffer. Graphite particles can attach to gas bubbles under all tested conditions in the range pH 3 to pH 10. The attractive forces for spherical graphite are strongest at high salt concentrations and pH 3. The conditions for the attachment of NMC to gas bubbles were evaluated with simulations using the Stokes–Reynolds–Young–Laplace model for film drainage, under consideration of DLVO forces and a hydrodynamic slip to account for irregularities of the particle surface. CP-AFM measurements in the capillary force regime provide additional parameters for the modeling of salt flotation, such as the force and work of detachment. The contact angles of graphite and NMC particles during retraction and detachment from gas bubbles were obtained from a quasi-equilibrium model using CP-AFM data as input. All CP-AFM experiments and theoretical results suggest that pristine NMC particles do not attach to gas bubbles during flotation, which is confirmed by the low rate of NMC recovery in batch flotation tests. Full article

Understanding the early-stage physical interactions between polymeric membranes and supersaturated salt solutions is crucial for advancing membrane-assisted crystallization (MCr) processes. In this study, we employed molecular dynamics (MD) simulations to investigate the short-term morphological response of an isotactic polypropylene (PP) membrane in contact with LiF solutions at different concentrations (5.8 M and 8.9 M) and temperatures (300–353 K), across multiple time points (0, 150, and 300 ns). These data were used as input for computational fluid dynamics (CFD) analysis to evaluate structural descriptors of the membrane, including tortuosity, connectivity, void fraction, anisotropy, and deviatoric anisotropy, under varying thermodynamic conditions. The results show subtle but consistent rearrangements of polymer chains upon exposure to the hypersaline environment, with a marked reduction in anisotropy and connectivity, indicating a more compact and isotropic local structure. Surface charge density analyses further suggest a temperature- and concentration-dependent modulation of chain mobility and terminal group orientation at the membrane–solution interface. Despite localized rearrangements, the membrane consistently maintains a net negative surface charge. This electrostatic feature may influence ion–membrane interactions during the crystallization process. While these non-reactive, short-timescale simulations do not capture long-term degradation or fouling mechanisms, they provide mechanistic insight into the initial physical response of PP membranes under MCr-relevant conditions. This study lays a computational foundation for future investigations bridging atomistic modeling and membrane performance in real-world applications. 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

Water supply and sewage drainage pipes have a critical role to play in the provision of clean water and sanitation, and pipe material selection influences infrastructure life, water quality, and microbial communities. Zinc-containing compounds are highly valued due to their mechanical properties, anticorrosion behavior, and antimicrobial properties. However, the effect of zinc salts, such as zinc sulfate heptahydrate and zinc chloride, on biofilm-forming bacteria, including Escherichia coli and Enterococcus faecalis, is not well established. This study investigates the antibacterial properties of these zinc salts under simulated pipeline conditions using minimum inhibitory concentration assays, biofilm production assays, and antibiotic sensitivity tests. Findings indicate that zinc chloride is more antimicrobial due to its higher solubility and bioavailability of Zn²⁺ ions. At higher concentrations, zinc salts inhibit the development of a biofilm, whereas sub-inhibitory concentrations enhance the growth of biofilm, suggesting a stress response in bacteria. zinc chloride also enhances antibiotic efficacy against E. coli but induces resistance in E. faecalis. These findings highlight the dual role of zinc salts in preventing biofilm formation and modulating antimicrobial resistance, necessitating further research to optimize material selection for water distribution networks and mitigate biofilm-associated risks in pipeline systems. Full article

The suitability of 347H stainless steel (SS347H) for chloride salt environments is critical in selecting materials for next-generation concentrated solar power (CSP) systems. This study investigated the corrosion behavior of SS347H in a ton-scale purification system with continuously flowing chloride salt under three conditions: exposure to NaCl-KCl-MgCl₂ molten salt vapor, immersion in molten salt, and at the molten salt surface interface. Results revealed that corrosion was most severe in the molten salt vapor, where HCl steam facilitated Cl⁻ reactions with Fe and Cr in the metal, causing dissolution and forming deep corrosion pits. At the interface, liquid Mg triggered displacement reactions with Fe²⁺/Cr²⁺ ions in the salt, depositing Fe and Cr onto the surface, which reduced corrosion intensity. Within the molten salt, Mg’s purification effect minimized impurity-induced corrosion, resulting in the least damage. In all cases, the primary corrosion mechanism involves the dissolution of Fe and Cr, with the formation of minor MgO. These insights provide valuable guidance for applying 347H stainless steel in chloride salt environments. Full article

Salinity stress is a primary abiotic constraint limiting global crop productivity, with progressive soil salinization inducing growth inhibition and physiological dysfunction in plants. Although melatonin (MT) has been extensively documented to enhance stress adaptation, the underlying mechanisms through which it mediates salt tolerance by integrating physiological processes remain unclear. This study investigated the effects of varying MT concentrations on photosynthetic performance, plant water relations, water-use efficiency, and stress-responsive physiological parameters in tomatoes, aiming to identify the key physiological pathways for MT-mediated salt stress mitigation. The results showed that salt stress significantly reduced the leaf relative water content and root hydraulic conductivity, suppressed the photosynthetic rate, and ultimately caused significant reductions in the aboveground and root biomass. MT spraying effectively improved leaf water status and root water uptake capacity, enhancing the photosynthetic rate and water-use efficiency, thereby providing material and energy support for plant growth. Furthermore, MT spraying increased the total antioxidant capacity in leaves and promoted the synthesis of phenolic and flavonoid compounds, thereby reducing oxidative damage. Simultaneously, it stimulated the accumulation of osmolytes to enhance cellular osmotic adjustment capacity and optimized ion uptake to maintain cellular ion homeostasis. Among the tested concentrations, 100 μM MT showed the most significant alleviative effects. This concentration comprehensively enhanced the salt tolerance and growth performance of tomato plants by synergistically optimizing water use, photosynthetic function, antioxidant defense, and ion balance. In conclusion, these findings provide experimental evidence for elucidating the physiological mechanisms underlying MT-mediated salt tolerance in tomatoes and offer theoretical references for the rational application of MT in crop production under saline conditions. Full article

The use of chloride-based deicing salts, particularly sodium chloride (NaCl) and calcium chloride (CaCl₂), is a common practice in cold regions for maintaining road safety during winter. However, the accumulation of salt residues in adjacent soils poses serious environmental threats, including reduced pH, increased electrical conductivity (EC), disrupted soil structure, and plant growth inhibition. This study aimed to evaluate the combined effect of activated carbon (AC) and Pennisetum alopecuroides, a salt-tolerant perennial grass, in alleviating salinity stress under deicer-treated soils. A factorial greenhouse experiment was conducted using three fixed factors: (i) presence or absence of Pennisetum alopecuroides, (ii) deicer type (NaCl or CaCl₂), and (iii) activated carbon mixing ratio (0, 1, 2, 5, and 10%). Soil pH, EC, and ion concentrations (Na⁺, Cl⁻, Ca²⁺) were measured, along with six plant growth indicators. The results showed that increasing AC concentrations significantly increased pH and reduced EC and ion accumulation, with the 5% AC treatment being optimal in both deicer systems. Plant physiological responses were improved in AC-amended soils, especially under CaCl₂ treatment, indicating less ion toxicity and better root zone conditions. The interaction effects between AC, deicer type, and plant presence were statistically significant (p < 0.05), supporting a synergistic remediation mechanism involving both adsorption and biological uptake. Despite the limitations of short-term controlled conditions, this study offers a promising phytomanagement strategy using natural adsorbents and salt-tolerant plants for sustainable remediation of salt-affected soils in road-adjacent and urban environments. Full article

Agriculture and animal feeding operations are responsible for 87% of ammonia emissions in the UK. Controlling NH₃ concentrations below 20 ppm is crucial to preserve workers’ and livestock’s well-being. Therefore, ammonia control systems are required for maintaining adequate air quality in livestock facilities. This study assessed the ammonia reduction efficiency of a novel air pollution abatement (APA) system used in a pig farm building. The monitoring duration was 11 weeks. The results were compared with the baseline from a previous pig cycle during the same time of year in 2023. A ventilation-controlled room was monitored during a two-phase campaign, and the actual ammonia concentrations were measured at different locations within the site and at the inlet/outlet of the APA system. A 98% ammonia reduction was achieved at the APA outlet through NH₃ absorption in tap water. Ion chromatography analyses of farm water samples revealed NH₃ concentrations of up to 530 ppm within 83 days of APA operation. Further scanning electron microscopy and energy-dispersive X-ray inspections revealed the presence of salts and organic/inorganic matter in the solid residues. This research can contribute to meeting current ammonia regulations (NECRs), also by reusing the process water as a potential nitrogen fertiliser in agriculture. Full article

High-power lithium-ion batteries impose stringent requirements on output power. Tetramethylene sulfone (TMS), serving as a novel electrolyte additive, effectively enhances the stability of electrolytes under high-voltage conditions due to its high flash point and high dielectric constant, thereby boosting the output performance of lithium-ion batteries. In this work, we selected lithium hexafluorophosphate (LiPF₆) as the lithium salt, using a solvent carrier consisting of a mixture of ethylene carbonate (EC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC). TMS was added as an additive to create a novel high-power electrolyte system. We prepared five electrolytes with different TMS concentrations and conducted in-depth investigations into their impacts on the performance of lithium-ion batteries. The findings indicate that the electrolytes with TMS ratios of 2 wt% and 5 wt% demonstrated good synergistic cathode–anode stability in the NCM//soft carbon system, and the electrolyte with a 5 wt% TMS ratio demonstrated the most significant improvement in the overall performance of the full battery. Full article

Salt stress is a major constraint to seed germination and early seedling growth in rice, affecting crop establishment and productivity. To understand the mechanisms underlying salt tolerance, we investigated two rice varieties with contrasting responses as follows: salt-tolerant sea rice 86 (SR86) and salt-sensitive P559. Germination assays under increasing NaCl concentrations (50–300 mM) revealed that 100 mM NaCl induced clear phenotypic divergence. SR86 maintained bud growth and showed enhanced root elongation under moderate salinity, while P559 exhibited significant growth inhibition. Transcriptomic profiling of buds and roots under 100 mM NaCl identified over 3724 differentially expressed genes (DEGs), with SR86 showing greater transcriptional plasticity, particularly in roots. Gene ontology enrichment revealed tissue- and genotype-specific responses. Buds showed enrichment in photosynthesis-related and redox-regulating pathways, while roots emphasized ion transport, hormonal signaling, and oxidative stress regulation. SR86 specifically activated genes related to photosystem function, DNA repair, and transmembrane ion transport, while P559 showed activation of oxidative stress-related and abscisic acid (ABA)-regulated pathways. Hormonal profiling supported transcriptomic findings as follows: both varieties showed increased gibberellin 3 (GA3) and gibberellin 4 (GA4) levels under salt stress. SR86 showed elevated auxin (IAA) and reduced jasmonic acid (JA), whereas P559 maintained stable IAA and JA levels. Ethylene precursor and salicylic acid levels declined in both varieties. ABA levels rose slightly but not significantly. These findings suggest that SR86’s superior salt tolerance results from rapid growth, robust transcriptional reprogramming, and coordinated hormonal responses. This study offers key insights into early-stage salt stress adaptation and identifies molecular targets for improving stress resilience in rice. Full article

Excess-sulfate phosphogypsum slag cement (EPSC), offering the potential for large-scale phosphogypsum (PG) utilization, has drawn significant attention. However, its susceptibility to salt erosion in marine/saline environments remains unquantified, hindering engineering applications. This study, therefore, systematically investigates the effect of various salts (NaCl, MgCl₂, KCl, and Na₂SO₄) at different concentrations (0.5–1.5%) on the hydration mechanism and performance of EPSC using rheometry, strength tests, and microstructural characterization (XRD/SEM-EDS). The findings reveal that EPSC exhibits low initial yield stress and plastic viscosity, both of which increase over time. The addition of Na⁺, Cl⁻, and SO₄²⁻ ions promotes hydration and flocculent structure formation in the EPSC paste, thereby enhancing the yield stress and plastic viscosity. In contrast, Mg²⁺ and K⁺ ions inhibit the hydration reaction, although Mg²⁺ temporarily increases the plastic viscosity by forming Mg(OH)₂ during the initial stage of the reaction. Both Na₂SO₄ and NaCl improve mechanical properties when their concentrations are within the 0.5–1.0% range; however, excessive amounts (>1%) negatively impact these properties. Significantly, adding 0.5% NaCl significantly improves the mechanical properties of EPSC, achieving a 28-day compressive strength of 51.06 MPa—a 9.5% increase compared to the control group. XRD and SEM-EDX analyses reveal that NaCl enhances pore structure via Friedel’s salt formation, while Na₂SO₄ promotes the early nucleation of ettringite. However, excessive ettringite formation in the later stages of the hydration reaction due to Na₂SO₄ may negatively affect compressive strength due to the inherent abundance of SO₄²⁻ in the EPSC system. Therefore, attention should be paid to the effect of excessive SO₄²⁻ on the system. These results establish salt-type/dosage thresholds for EPSC design, enabling its rational use in coastal infrastructure where salt resistance is critical. Full article

This study presents a sustainable approach for synthesizing high-performance activated carbon from Spirulina Alga through hydrothermal carbonization followed by chemical activation using potassium hydroxide. The resulting activated carbon exhibited a high Brunauer–Emmett–Teller (BET) surface area of 1747 m²/g and a total pore volume of 1.147 cm³/g, with micropore volume accounting for 0.4 cm³/g. Characterization using Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDS), X-ray Photoelectron Spectroscopy (XPS), and gas adsorption analyses confirmed the presence of hierarchical micro- and mesoporosity as well as favorable surface functional groups. The synthesized carbon was used to fabricate electrodes for membrane capacitive deionization (MCDI) along with cation and anion-selective membranes, which were then tested with saline water (500–5000 ppm) and synthetic hard water (898 ppm of total salts). The salt adsorption capacity (SAC) reached 25 (batch) to 40 (continuous) mg/g, while rapid adsorption rates with average salt adsorption rates (ASARs) values exceeding 10 (batch) to 30 (continuous) mg·g⁻¹·min⁻¹ during early stages were obtained. Batch MCDI experiments demonstrated a higher SAC compared to continuous operation, with non-monotonic trends in SAC observed as a function of feed concentration. Ion adsorption kinetics were influenced by ion valency, membrane selectivity, and pore structure. The specific energy consumption (SEC) was calculated as 8–21 kJ/mol for batch and 0.1–0.5 kJ/mol for continuous process. These performance metrics are on par with or surpass those reported in the recent literature for similar single-electrode CDI configurations. The results demonstrate the viability of using Alga-derived carbon as an efficient and eco-friendly electrode material for water desalination technologies. Full article