Salt Concentration Research Articles

An Experimental Validation-Based Study of Airport Pavement Icing Mechanisms in Saline Environments and the Development of a Simplified Prediction Model

Runway icing presents a significant challenge to aviation safety, especially in saline environments, where comprehending the icing mechanisms and predicting the icing onset are crucial for efficient airport operations. This study developed a specialized experimental apparatus to examine the mechanisms of airport pavement icing under controlled conditions. The apparatus, comprising an environmental chamber, a data acquisition system, and a scaled pavement structure, allowed for detailed simulations of various environmental factors. The experiments specifically examined the effects of the air temperature (−3 °C to −20 °C), wind speed (2 m/s to 6 m/s), and deicing salt concentration (0% to 80%) on the icing process. The results demonstrated that higher wind speeds and lower temperatures significantly accelerated the pavement surface cooling, leading to earlier icing onset. Under the most extreme conditions, the pavement reached critical icing temperatures within 15 min. In contrast, higher deicing salt concentrations delayed the icing onset by up to 67 min and 33 s at an 80% concentration, effectively lowering the pavement surface temperature. A comparison of the experimental data with the theoretical predictions showed initial consistency, although the discrepancies increased over time. This study culminated in the development of a simplified prediction model, which was validated against the experimental results, offering a practical tool for airport operators to manage runway safety during winter conditions.

Isolation and Identification of Four Strains of Bacteria with Potential to Biodegrade Polyethylene and Polypropylene from Mangrove.

With the rapid growth of global plastic production, the degradation of microplastics (MPs) has received widespread attention, and the search for efficient biodegradation pathways has become a hot topic. The aim of this study was to screen mangrove sediment and surface water for bacteria capable of degrading polyethylene (PE) and polypropylene (PP) MPs. In this study, two strains of PE-degrading bacteria and two strains of PP-degrading candidate bacteria were obtained from mangrove, named Pseudomonas sp. strain GIA7, Bacillus cereus strain GIA17, Acinetobacter sp. strain GIB8, and Bacillus cereus strain GIB10. The results showed that the degradation rate of the bacteria increased gradually with the increase in degradation time for 60 days. Most of the MP-degrading bacteria had higher degradation rates in the presence of weak acid. The appropriate addition of Mg2+ and K+ was favorable to improve the degradation rate of MPs. Interestingly, high salt concentration inhibited the biodegradation of MPs. Results of scanning electron microscopy (SEM), atomic force microscopy (AFM), and Fourier-transform infrared spectroscopy (FTIR) indicated the degradation and surface changes of PP and PE MPs caused by candidate bacteria, which may depend on the biodegradation-related enzymes laccase and lipase. Our results indicated that these four bacterial strains may contribute to the biodegradation of MPs in the mangrove environment.

Effects of fermentation conditions (salt concentration, temperature, and pH) on Lactobacillus strains for induction of interleukin-12 in the exposed murine splenocytes

The present work aimed to assess the stresses of temperature, salt concentration, and pH on Lactobacillus gasseri 54C, Lactiplantibacillus plantarum ATCC 14917, and 11SH in fermented culture medium and their effects on interleukin-12 (IL-12) induction in murine splenocytes. First, the strains were fermented under different microbial stress conditions at salt concentrations (2, 4, and 6% w/v), temperatures (30 and 42°C), and pH levels (4, 5, and 6), as well as their combined conditions. Then, they were heat-killed, lyophilized, and exposed to murine splenocytes. The IL-12 induction was measured using the immunoassay method. It was indicated that the induction of IL-12 depended on the culture conditions, as it was increased by the fermentation strains under microbial stresses with the higher temperature (42°C), lower salt concentration (%2), and lower pH level (4). It seems that the bacterial cells' integrity is essential to stimulate the induction of IL-12.

Influence of pH and salt conditions on extraction efficiency and functional properties of Macrotermes nigeriensis protein concentrate for food applications

The search for alternative proteins from non-conventional sources for food processing has become important due to the shortage of conventional protein sources. Protein extractability from Macrotermes nigeriensis and its functional properties were investigated under various conditions of pH (2–10) and salt concentration (0.1–1.0 M). Extracted proteins were precipitated through pH adjustment and micellization, respectively. Results showed that maximum protein extractability was 68% and 62.1% at 0.5 M salt concentration and pH10.0, respectively. Salt-extracted protein-rich fraction (SP) had the highest protein composition (68.68 ± 0.41 g/100 g), seconded by alkaline-extracted protein-rich fraction (AP) (62.91 ± 0.53 g/100 g), compared with the raw and defatted fraction (34.36 ± 0.44 and 42.12 ± 0.15 g/100 g), respectively. The highest emulsion capacity (49%) and emulsion stability (35%) were recorded in alkaline pH 10.0. In comparison, the highest foaming capacity (24%) and foaming stability (16%) were recorded in the salt-extracted fraction at 6%. This information could be useful for further studies on the food application potential of proteins isolated from edible M. nigeriensis.Graphical

Hexafluoroisopropanol-based deep eutectic solvents for efficient aqueous two-phase extraction of flavonoids from Flos Sophorae Immaturus

Aqueous two-phase systems (ATPSs) based on deep eutectic solvents (DESs) are green extraction and separation media and have demonstrated remarkable potential for extracting bioactive substances from natural matrices. However, thus far, flavonoid extraction using DES-based ATPSs has rarely been reported. In this study, the state-of-the-art technique using DES-based ATPSs was employed for developing an effective method for extracting flavonoids from Flos Sophorae Immaturus (FSI). DESs prepared with hexafluoroisopropanol (HFIP) and five quaternary ammonium salts, N111xCl (x = 1, 4, 8, 12, and 16), were used as the hydrogen bond donor and hydrogen bond acceptors, respectively, for constructing ATPSs with K2HPO4 as a salting-out agent and utilized for extracting flavonoids from FSI. Fourier-transform infrared, 1H nuclear magnetic resonance, 1H–1H nuclear Overhauser effect spectroscopy analyses, and density functional theory calculations were implemented to demonstrate the successful preparation of DESs. The DES containing dodecyltrimethylammonium chloride and HFIP with a molar ratio of 1:2 was screened as the optimal DES, showing a higher extraction efficiency and yield of flavonoids compared to those of other DESs and the traditional solvent ethanol. Subsequently, various experimental parameters (amount of DES, salt concentration, liquid-to-solid ratio, extraction temperature, and ultrasonic time) for the extraction process were studied comprehensively and optimized using response surface methodology. The yield of flavonoids from FSI was 21.05 % under optimal extraction conditions (amount of DES = 2 g, salt concentration = 0.21 g/mL, liquid-to-solid ratio = 81 mL/g, and extraction temperature = 60 ℃), which is close to the predicted value of 20.82 %. Extraction mechanisms underlying the performance of DES-based ATPSs during the extraction of bioactive substances are yet to be fully understood. Therefore, molecular dynamics (MD) simulations were employed with rutin as the target compound to probe the extraction mechanism under DES-based ATPS conditions, and the results revealed that hydrogen-bonded frameworks are pivotal for the extraction process. Moreover, the existence of K2HPO4 was found to promote not only the increase in hydrogen bonding networks and π–π stacking interactions within rutin molecules but also the increase in solvent flexibility, facilitating the extraction process. The present work offers a promising approach for flavonoid extraction using DES-based ATPSs. Interpreting the extraction mechanism at the molecular level by adopting the MD simulation technique provides new insights that enable a deeper understanding and aid in the design of the extraction process for bioactive substances under DES-based ATPS circumstances.

In vitro cluster buds regeneration and control of shoot tip necrosis in tissue cultures of Trichosanthes cucumerina L.

Trichosanthes cucumerina L. is a medicinal vine with great potential that can be used as a vegetable. In this study, an efficient in vitro regeneration system of T. cucumerina was established by inducing adventitious buds and controlling Shoot Tip Necrosis (STN) in the in vitro culture. The results of hormone single factor and orthogonal experiments showed that 6-BA had a significant effect on inducing adventitious buds. The best medium for bud proliferation was MS + 6-BA 3.0 mg·L− 1 + KIN 2.0 mg·L− 1 + NAA 0.5 mg·L− 1, and the proliferation capacity was 14.68. However, after three consecutive subcultures, a higher incidence of STN (78.86%) was observed. The results of the STN control experiment showed that reducing the concentration of inorganic salt, shortening the subculture interval, and increasing the Ca2+ in the medium could effectively control the occurrence of STN. However, reducing the concentration of inorganic salt and shortening the subculture interval excessively reduces the proliferation capacity significantly. Considering both the incidence of STN and proliferation capacity, the measures proposed in this study to alleviate STN were to keep the concentration of inorganic salt unchanged, adjust the subculture interval from 45 days to 40 days, and increase the Ca2+ concentration in the medium to 480 mg·L− 1. When the subculture interval was 40 d, the stem segments obtained the lowest STN incidence (8.3%) and higher shoot proliferation capacity (10.02) on the medium of MS + 3.0 mg·L− 1 6-BA + 2.0 mg·L− 1 KIN + 0.5 mg·L− 1 NAA + 360.36 mg·L− 1 Ca2+ (360 mg·L− 1 is the concentration of additional calcium to be added, and after this addition, the total calcium concentration in the MS medium was 480.48 mg·L− 1). The best rooting medium for stem segments was MS + 0.50 mg·L− 1 NAA; the rooting rate was 100%, and no STN occurred. After acclimation, the survival rate of the rooted plantlet reached 95% after 40 days in the soil matrix of coconut husk: humus soil: perlite = 2: 2: 1 (v/v). The results of this study not only reveal the mechanism of STN in T. cucumerina, but also provide technical support and a theoretical basis for its further breeding and cultivation.

Experimental measurements and thermodynamic modeling of dissociation pressure of CO2 hydrate in sulfate solutions

Carbon capture and storage (CCS) has been a popular strategy to mitigate climate change and has attracted significant attention from both industry and academia. CO2 can be stored in the form of CO2 hydrate in deeper locations in an ocean, which makes it a potential option for CO2 sequestration. Dissolved salts in the ocean brine can significantly affect the dissociation pressure of CO2 hydrate. Sulfate salts are one of the most common salt species in the oceanic brine. Although various experimental studies have been conducted to investigate the phase behavior of CO2 hydrate in brine, few studies focus on the effect of sulfate salts on the dissociation pressure of CO2 hydrate. In this study, we build an in-house experimental setup to investigate the effect of monovalent and divalent sulfate salts on the dissociation pressure of CO2 hydrate. The dissociation pressure of CO2 hydrate in Na2SO4, K2SO4, MgSO4, and CuSO4 aqueous solutions is measured using the isochoric pressure search method at different concentrations over the temperature range of 274.36–––282.15 K and the pressure range of 1.50–––4.03 MPa. A hybrid methodology incorporating the Soave-Redlich-Kwong Equation of State (SRK EOS), the van der Waals-Platteeuw (vdW-P) model, and the Pitzer model is applied to predict the dissociation pressure of CO2 in sulfate solutions. In addition, the dissociation enthalpies of CO2 hydrate in these sulfate solutions are calculated using the Clausius-Clapeyron equation based on the measured dissociation points. The experimental results show that the dissociation pressure of CO2 hydrate in Na2SO4, K2SO4, and MgSO4 solutions is higher than that in pure water, and the dissociation pressure of CO2 hydrate in sulfate solutions increases with an increasing salt concentration. Conversely, CuSO4 barely affects the dissociation pressure of CO2 hydrate, which is mainly attributed to the lower molar concentration of the ions compared with the other salt solutions and the ion specificity of Cu2+. The prediction results are in alignment with the experimental data measured in this study, which proves the feasibility of the thermodynamic model in predicting the dissociation pressure of CO2 hydrate in sulfate solutions. Additionally, the calculated dissociation enthalpies of CO2 hydrate show a dependence on both temperature and salt concentration. It is also revealed that Cu2+ exhibits ion specificity in affecting the dissociation enthalpy of CO2 hydrate, likely due to its distinct ability to impact the cage occupancy of CO2 hydrate compared with the other ions. These findings enhance our understanding of the impact of sulfate salts on the dissociation behavior of CO2 hydrate and offer valuable insights for CO2 sequestration.

Preparation, characterization, and stability of chitosan-tremella polysaccharide layer-by-layer encapsulated astaxanthin nanoemulsion delivery system

In this study, a layer-by-layer (LBL) encapsulated astaxanthin (Ast) nanoemulsion delivery system based on chitosan (CS) and tremella polysaccharide (TP) was successfully developed. The system constructed an Ast-CS-TP emulsion with high encapsulation efficiency and an excellent stability profile by utilizing the opposite charge properties of CS and TP. This study evaluated the effects of different stresses (including temperature, salt addition, pH, UV irradiation, and centrifugal force) on the emulsion's stability. To further investigate the protective mechanism of the emulsions, we performed antioxidant activity experiments after UV treatment. Additionally, an in vitro digestion experiment was conducted to assess the behavior of Ast emulsion under simulated gastrointestinal conditions. The stability correlation coefficients were calculated using the Python database Pandas. The results showed that Ast-CS-TP emulsions exhibited turbidity and enhanced homogeneity with a small particle size of around 400 nm and a high absolute zeta potential of 35 mV and exhibited excellent stability under various stresses. The Ast-CS-TP emulsions also exhibited pH-responsive release at pH ≥ 7, consistent with pH changes in the gastrointestinal tract, and were stable in highly concentrated salt solutions. We found that the CS and TP layers significantly improved the photostability of Ast. CS and TP significantly enhanced Ast's oral bioavailability. The stability correlation coeffcients showed that pH and salt concentration were the largest factors that affected the stability of the emulsion. This study provided important insights into the encapsulation and targeting of Ast, providing a theoretical foundation and technical guidance for the comprehensive utilization of Ast.

An orientational graphene/bamboo evaporator for efficient solar-powered steam generation and desalination

Solar-powered steam generation and desalination by interfacial solar steam generation (ISSG) are promising techniques for addressing the freshwater shortage. However, the insufficient conversion efficiency and complex pollutant components confine its further extension and application. This study innovatively constructs an orientational graphene/bamboo evaporator (GBE), maintaining a solvent-accessible surface area and reducing vaporization enthalpy by selective delignification and torrefaction. The GBE device features a channel oriented from bamboo, consolidating the parallel architecture with multilayer biofilm filtration that guides efficient bulk-water pumping, steam release, and pollutant interception. The GBE demonstrates full-spectrum optical absorption at 90.5 % and 33.4 s response time while maintaining operational stability across different salt concentrations and natural water environments. The GBE achieved an evaporation rate of 1.53 kg m-2h-1as 4.34 enhancement factor under 1 kW/m−2(−|-) illumination, surpassing microplastics (99.84 %) and tetracycline (99.87 %) desalination. This work provides a high-performance and innovative approach to bamboo evaporator design, offering a viable and alternative method to address freshwater shortage.

Fabrication of stable hydrogel microspheres with hydrophobic shell using water-in-water (W/W) Pickering emulsion template

Hydrogel microspheres are promising for food applications. The water-in-oil (W/O) emulsion template is commonly used to prepare the hydrogel microspheres. However, this method often involves synthetic surfactants and toxic organic solvents to remove the oil phase. The swelling problem of the resultant microspheres is another obstacle. In this study the water-in-water (W/W) emulsion template of gelatin-in-dextran was used to prepare the hydrogel microspheres, without the addition of surfactants, toxic reagents and high energy input. To prevent swelling, zein particles modified with alginate were served as a hydrophobic shell of the gelatin core. The formation evolution of these core–shell microspheres and its relevant factors including phase behavior of the immiscible gelatin/dextran, the binding of zein/alginate and the addition of the modified zein particles were investigated. It was found that small amount of alginate could induce zein particles to absorb on the gelatin surface, whereas the excess led to absorption competition. When using 0.6 wt% particles with zein/alginate ratio of 1:0.5, the ideal core–shell microspheres which were fully covered by the particles and with a self-supporting architecture in uniform size (18.8 ± 0.1 μm) and spherical shape were obtained. These microspheres showed remarkable stability under the conditions of heat treatment, varied pHs and salt concentrations and long-term storage either in refrigerator or room environment. Their sizes were easily manipulated by adjusting the concentration and molar mass of the biopolymers. It is believed that the desired stability and tunable sizes of these edible core–shell microspheres could contribute the development of their applications in foods.

Sticky Science: Using Complex Coacervate Adhesives for Biomedical Applications.

Tissue adhesives are used for various medical applications, including wound closure, bleeding control, and bone healing. Currently available options often show weak adhesion or cause adverse effects. Recently, there has been an increasing interest in complex coacervates as medical adhesives. Complex coacervates are formed by mixing oppositely charged macromolecules that associate and undergo liquid-liquid phase separation, in which the dense bottom phase is the complex coacervate. Complex coacervates are strong and often biocompatible, and show strong underwater adhesion. The properties of the resulting materials are tunable by intrinsic factors such as polymer chemistry, molecular weight, charge density, and topology of the macromolecules, as well as extrinsic factors such as temperature, pH, and salt concentration. Therefore, complex coacervates are interesting new candidates for medical adhesives. In this review, it is described how complex coacervates form and how different factors influence their behavior. Next, an overview of recent studies on complex coacervates in the context of medical adhesives is presented. The application of complex coacervates as hemostatic or embolic agents, skin or bone repair adhesives, and soft tissue sealants is discussed. Lastly, additional possibilities for utilizing these materials in the future are discussed.

Metataxonomy and pigments analyses unravel microbial diversity and the relevance of retinal-based photoheterotrophy at different salinities in the Odiel Salterns (SW, Spain)

Salinity has a strong influence on microorganisms distribution patterns and consequently on the relevance of photoheterotrophic metabolism, which since the discovery of proteorhodopsins is considered the main contributor to solar energy capture on the surface of the oceans. Solar salterns constitute an exceptional system for the simultaneous study of several salt concentrations, ranging from seawater, the most abundant environment on Earth, to saturated brine, one of the most extreme, which has been scarcely studied. In this study, pigment composition across the salinity gradient has been analyzed by spectrophotometry and RP-HPLC, and the influence of salinity on microbial diversity of the three domains of life has been evaluated by a metataxonomic study targeting hypervariable regions of 16S and 18S rRNA genes. Furthermore, based on the chlorophyll and retinal content, we have estimated the relative abundance of rhodopsins and photosynthetic reaction centers, concluding that there is a strong correlation between the retinal/chlorophyll a ratio and salinity. Retinal-based photoheterotrophy is particularly important for prokaryotic survival in hypersaline environments, surpassing the sunlight energy captured by photosynthesis, and being more relevant as salinity increases. This has implications for understanding the survival of microorganisms in extreme conditions and the energy dynamics in solar salter ponds.

Biological and Photocatalytic Activities of Silver Nanoparticles Synthesized from the Leaf Extract of Euphorbia royleana Boiss.

Silver nanoparticles (AgNPs) have gained significance due to their practical use in the medicinal field, especially in the treatment of tumors and cancer. The current article explores a green synthetic method for the preparation of AgNPs using leaf extract of Euphorbia royleanas. The synthesis was conducted at different parameters like concentration of AgNO3, pH, salt concentration, temperature and time to optimize best results for their biochemical applications. It was validated through UV-V spectroscopy (400-450 nm) with 1:3 (concentration ratio of leaf ethanolic extract and 1 mM AgNO3 solution) at a pH value of 8 at 35oC, which were the best optimization conditions. The FTIR spectral bands showed the presence of C-N and -OH functional groups, indicating that -OH stretching and the aliphatic -C-H stretching were involved in the reduction of Ag ions. The XRD pattern showed the face-centered cubic structure of silver nanoparticles. The results of SEM revealed that AgNPs were predominantly spherical in shape, mono-dispersed, and arranged in scattered form. EDX analysis testified the presence of metallic silver along with other elements like Cl, C, and O. The investigation of biochemical parameters showed that AgNPs were influential in the discoloration of dye wastewater (methylene blue ), where 80% of dye color was removed in 20 min, followed by the significant (p < 0.05) analgesic activity with an inhibition percentage of 86.45% at a dose of 500 mg/kg. Similarly, the antioxidant activity with the highest percent inhibition was 55.4% (p < 0.0001), shown by the AgNPs at 500 μg/mL. AgNPs showed a 30 mm zone of inhibition at 100 μl/mL against Aspergillus niger. It was concluded that AgNPs provide a baseline in medical technology for the treatment of simple to chronic diseases.

Different taste map for amiloride sensitivity, response frequency, and threshold to NaCl in the rostral nucleus of the solitary tract in rats.

Studies on taste bud cells and brain stem relay nuclei suggest that alternative pathways convey information regarding different taste qualities. Building on the hypothesis that amiloride (epithelial Na channel antagonist)-sensitive neurons respond to palatable salt (low-concentration) and amiloride-insensitive neurons respond to aversive salt (high-concentration), we investigated the histological distribution of taste-sensitive neurons in the rostral nucleus of the solitary tract in rats and their NaCl and amiloride sensitivities. We recorded neuronal activity in extracellular single units using multi-barrel glass micropipettes and reconstructed their locations on the rostrocaudal and mediolateral axes. Seventy-three taste-sensitive neurons were categorized into the best-taste category. The amiloride sensitivities of the 31 neurons were examined for 0.1, 0.2, 0.4, and 0.8 M NaCl. The neuronal distribution of amiloride-sensitive neurons was located in the lateral region, while amiloride-insensitive neurons were located in the medial region. The amiloride-sensitive neurons responded to low salt concentrations, signaling the NaCl levels required by body fluids. Amiloride-insensitive neurons were silent at low salt concentrations but may function as warning signals for high salt concentrations. Low-threshold and/or high-response neurons were located in the rostrolateral region. In contrast, high-threshold and/or low-response neurons were located in the caudal-medial region.

Growing polyion complex micelles: kinetics and mechanism of electrostatic template polymerization and assembly

HypothesisElectrostatic-templated polymerization (ETP) is a recently developed strategy for robust fabrication of stable polyion complex (PIC) micelles with regulated size and morphology, yet the kinetics and mechanism about this one pot process remain elusive. ExperimentsIn ETP method, ionic monomers are polymerized in the presence of an oppositely charged ionic-neutral diblock copolymer as template. We investigate the monomer conversion and electrostatic assembly as a function of time, under different polymerization conditions of ionic strength, pH, template/monomer molar ratio and the presence of a cross-linker. FindingsThe template copolymer accelerates the monomer conversion and formation of PIC micelles dependent on ionic strength and pH. The process follows the “Pick-up” mechanism, where monomers first convert into oligomers which complex with template to induce further chain growth and electrostatic assembly. Introducing cross-linker hardly impacts the reaction kinetics and “Pick-up” route, while it creates PIC micelles containing cross-linked ionic network assembly with the template. Further removing the template by concentrated salt provides purified ionic nanogels. The disclosed findings not only provide a better understanding of the polymerization-assembly process, but also optimize the controls of electrostatic-templated polymerization for the rational design and fabrication of diverse PIC micelles and polyelectrolyte particles.

Enhanced mechanical properties in transparent mullite glass-ceramics synthesized from EMT-type zeolites via spark plasma sintering

Transparent glass-ceramics offer a unique combination of optical clarity and the mechanical strength of ceramics, making them ideal for various advanced applications such as cell phone screens and telescope mirrors. However, traditional fabrication methods involve high temperatures and long processing times, which result in high energy consumption and limitations in material integration. In this study, we explore the fabrication of transparent mullite glass-ceramics from EMT-type zeolites using the spark plasma sintering (SPS) technique to address these challenges. By varying the concentrations of ammonium salts to replace Na+ in the zeolite, we modified the SiO2+Al2O3 content and successfully synthesized the mullite glass-ceramics at 950 °C. The resulting glass-ceramics exhibited high transmittance (>65 % in the visible region), improved mechanical properties with a Young's modulus up to 103 GPa, a Vickers hardness of 8.0 GPa, and an indentation fracture toughness of 1.8 MPa m1/2. X-ray diffraction and Raman spectroscopy confirmed the formation of mullite phases, with increased crystallinity and a strengthened glass structure, correlating with higher SiO2+Al2O3 content. The study demonstrates the potential of using high Al/Si ratio molecular sieves as precursors for high-performance glass-ceramics, offering significant advancements in both optical and mechanical properties.

Elucidating organic and nutrient transport mechanisms in polyelectrolyte modified membranes for selective nutrient recovery

This work focuses on understanding and analyzing the transport mechanisms of organics and nutrient ions (NH4+, K+) through polyelectrolyte-based membranes, aimed at the selective recovery of nutrients from nutrient-rich resources such as anaerobic digestate. In this study, commercial nanofiltration (NF) membranes were modified by the layer-by-layer (LbL) deposition of oppositely charged polyelectrolytes, utilizing a wide range of parameters such as polyelectrolyte type, deposition pH, salt (NaCl) concentration, polymer cross-linking, etc. Such modifications resulted in membranes exhibiting characteristics that indicate a trade-off relationship between nutrient passage and nutrients/organics selectivity. Our findings suggest that nutrient passage is primarily facilitated by surface charge, while size-exclusion plays a vital role in retaining the organics. Ionically crosslinked polyelectrolyte multilayer (PEM) membranes exhibit superior nutrient passage (up to ∼30 % higher) compared to commercial NF membranes, while covalently crosslinked PEM membranes achieve higher (∼12 % higher) organics rejection. In addition, membranes with such covalent crosslinking exhibit intra-nutrient (NH4+/K+) selectivity of ∼1.8, when tested with binary NH4+/K+ mixtures – a rather surprising membrane property, since both ions have similar hydrated radii. This study provides a fundamental framework of membrane design for selectively recovering nutrients from a variety of nutrient-rich sources.

Mangrove fungi in action: Novel bioremediation strategy for high-chloride wastewater

Bioremediation of extremely high-chloride wastewater poses significant challenges due to the adverse effects of elevated salt concentrations on most microorganisms, where chloride levels can be as high as 7% (w/v). Mangrove wetlands derived fungus, Aspergillus aculeatus, emerged as a promising candidate, capable of removing approximately 40% of chloride ions in environments with concentration of 15% (w/v), representative of industrial wastewater conditions. Transcriptomics and biochemical assays conducted under increasing salt conditions revealed that elevated chloride concentrations induce the expression and activity of S-adenosyl methionine-dependent methyltransferase, which facilitates the conversion of chloride into chloromethane. This is the first report characterizing the biological mechanism behind high salt tolerance and chloride removal capacity of Aspergillus aculeatus. This salt remediation mechanism may work as a starter for developing future bioremediation strategies to treat high-chloride wastewater using fungi, offering an eco-friendly alternative to traditional physical or chemical methods.

Benchmarking the Performance of Lithium and Sodium‐Ion Batteries With Different Electrode and Electrolyte Materials

ABSTRACTSodium‐ion (Na‐ion) batteries are considered a promising alternative to lithium‐ion (Li‐ion) batteries due to the abundant availability of sodium, which helps mitigate supply chain risks associated with Li‐ion batteries. Many studies have focused on the design of Li‐ion batteries, exploring their energy, power, and cost aspects. However, there is still a lack of similar research conducted on Na‐ion batteries. A comparison of the cell voltage characteristics and rate capability of sodium and lithium‐ion batteries using different types of electrodes and electrolytes. For sodium‐ion batteries electrolytes used are NaPF6 and NaClO4 and electrodes used are NaCoO2, NaNiO2, NaFePO4, (Na3V2(PO4)3), graphite, hard carbon, sodium metal, and sodium titanate. For lithium‐ion batteries with LiPF6 and KOH electrolytes and electrodes as LiCoO2, NMC, LVP, Li2MnSiO4, graphite, silicon, lithium titanate (LTO), lithium metal. A thorough analysis of six important performance metrics is part of the investigation: Ragone plots, Electrolyte salt concentration versus spatial coordinate, electrolyte potential versus spatial coordinate, Cell voltage versus battery cell state of charge, Cell voltage versus time, and state variable versus time. Comparing operating voltage and rated capacity NMC and graphite is selected for lithium‐ion batteries as this combination provides operating voltage up to 4.2 V and a rated capacity of 275 Wh/kg, for sodium‐ion for NaCoO2 and hard carbon which has an operating voltage of 2.5–3.8 V and rated capacity around 200 Wh/kg and another combination of electrode as NaFePO4 and sodium metal with NaClO4 electrolyte has a maximum operating voltage of 2.8–3.8 V and rated capacity around 200 Wh/kg. This paper shows significant influence of electrolyte selection on battery performance. The Ragone plots demonstrate that LiPF6 electrolytes in lithium‐ion batteries and NaPF6 electrolytes in sodium‐ion batteries both exhibit superior specific energy densities compared to their KOH and NaClO4 counterparts, respectively. The work presented in this paper encourages researchers to select alternate electrolytes and electrodes for lithium‐ion and sodium‐ion batteries in order to obtain optimal device performance.

Understanding the role of CaCl2 in salt substitute for low-salt and high-quality surimi products

Salt substitute has been widely used to prepare low-salt foods due to potential health benefits, though the role of CaCl2 in salt substitute and its unique impacts on food quality have been rarely investigated. In this study, comprehensive research has been conducted to elucidate the effects of replacing NaCl with varying concentrations of CaCl2 on the surimi gel characteristics. The introduction of CaCl2 interacted with surimi proteins differently from NaCl, thus leading to difference in protein aggregation behaviors and surimi gel properties. It has been found that a proper proportion of CaCl2 for NaCl substitution could create salt bridges between surimi proteins more effectively, resulting in an ordered, smooth and dense gel network with an increased water holding capacity (WHC) and improved gel strength. Furthermore, TGase activated by Ca2+ boosted the formation of ε-(γ-glutamyl) lysine bonds, which cross-linked surimi proteins to form a firm gel with a better three-dimensional structure. However, replacing NaCl with excessive amount of CaCl2 as divalent salts induced more serious protein aggregation, leading to water loss and gel properties deterioration. More specially, replacing NaCl with CaCl2 at 50% showed the best performance, as evidenced by the most abundant disulfide bonds and hydrophobic interactions, highest hardness and chewiness, and greatest storage modulus. This study provided new insights on developing high-quality surimi gels with significantly reduced salt concentration and improved gel characteristics.