High Salinity Environment Research Articles

Impact of static and dynamic foam properties on enhanced oil recovery: an experimental analysis

Foam performance is notably diminished in high-salinity environments. This study investigates foam stability at the optimal concentrations of various surfactants under different salinity conditions. Unlike many prior studies that focus on moderate salinity levels, this work specifically studies the surfactant performance under extreme salinity conditions representative of Persian Gulf seawater. Static tests were conducted using shaking bottle experiments, with brine salinities ranging from 0 to 4 wt% and surfactant concentrations between 0.1 and 0.5 wt%. For sodium dodecyl sulfate (SDS), foam stability was increased at higher salinity. This improvement was attributed to enhanced surfactant adsorption, which strengthened the liquid film stability and increased surface elasticity. To further explore the impact of surfactant type and concentration on oil recovery factor, a series of experiments were performed in a glass micromodel. The surfactant performance is highly dependent on the salinity of the injected solutions. Among the surfactants tested, Cetyl Trimethyl Ammonium Bromide (CTAB) demonstrated the highest oil recovery efficiency, particularly in conditions resembling Persian Gulf salinity, due to its superior ability to reduce interfacial tension (IFT). SDS also performed well, though its stability varied with salinity, whereas the effectiveness of Cocamidopropyl Betaine (betaine; CAPB) decreased significantly as salinity increased. The novelty of this research lies in the optimization of surfactant structures for micromodel tests and the comprehensive evaluation of surfactant performance across a range of salinities. The research meticulously determines the optimal surfactant concentrations based on foam half-life values, ensuring that the selected concentrations maximize foam stability and oil recovery efficiency.

A Novel Exopolysaccharide Produced by Sphingomonas sp. MT01 and Its Potential Application in Enhanced Oil Recovery.

Sphingan is a crucial exopolysaccharide (EPS) produced by Sphingomonas genus bacteria with wide-ranging applications in fields such as food, medicine, and petroleum. In this study, a novel sphingan, named MT gum, was overproduced from the wild-type strain Sphingomonas sp. MT01 at a yield of 25.6 g/L in a 5 L fermenter for 52 h at 35 °C. The MT gum was mainly composed of D-glucose (65.91%) and L-guluronic acid (30.69%), as confirmed by RP-HPLC, with Mw 7.24 × 105 Da. The MT gum exhibited excellent rheology and pseudoplasticity characteristics while maintaining function in high-temperature and high-salinity environments. The viscosity retention rates of MT gum (0.1%, w/v) were 54.06% (80 °C, 50,000 mg/L salinity) and 34.78% (90 °C, 50,000 mg/L salinity), respectively. The apparent viscosity of MT solutions (0.1%, w/v) was much higher than that of welan solutions under the same conditions. The MT gum also had the property of instant dissolution and completely swelled in 40 min. Meanwhile, the MT gum was resistant to 3-10 mg/L Fe2+ in the reservoir conditions, ensuring its application in offshore oil fields. These findings suggested that the biopolymer MT gum produced by the strain MT01 had significant potential in enhanced oil recovery (EOR) of high-temperature and high-salinity oil reservoirs.

Aquatic Invertebrate Antimicrobial Peptides in the Fight Against Aquaculture Pathogens.

The intensification of aquaculture has escalated disease outbreaks and overuse of antibiotics, driving the global antimicrobial resistance (AMR) crisis. Antimicrobial peptides (AMPs) provide a promising alternative due to their rapid, broad-spectrum activity, low AMR risk, and additional bioactivities, including immunomodulatory, anticancer, and antifouling properties. AMPs derived from aquatic invertebrates, particularly marine-derived, are well-suited for aquaculture, offering enhanced stability in high-salinity environments. This study compiles and analyzes data from AMP databases and over 200 scientific sources, identifying approximately 350 AMPs derived from aquatic invertebrates, mostly cationic and α-helical, across 65 protein families. While in vitro assays highlight their potential, limited in vivo studies hinder practical application. These AMPs could serve as feed additives, therapeutic agents, or in genetic engineering approaches like CRISPR/Cas9-mediated transgenesis to enhance resilience of farmed species. Despite challenges such as stability, ecological impacts, and regulatory hurdles, advancements in peptidomimetics and genetic engineering hold significant promise. Future research should emphasize refining AMP enhancement techniques, expanding their diversity and bioactivity profiles, and prioritizing comprehensive in vivo evaluations. Harnessing the potential of AMPs represents a significant step forward on the path to aquaculture sustainability, reducing antibiotic dependency, and combating AMR, ultimately safeguarding public health and ecosystem resilience.

Salinity-dependent effects of integrated biofloc technology on reproductive performance, biological responses, and offspring quality in red tilapia aquaculture

The study aims to evaluate the reproductive performance, serum biochemical indices, growth, antioxidant capacity, and immune response of Florida Red Tilapia (Oreochromis sp.) progeny reared at different salinity levels within biofloc technology (BFT) systems, focusing on egg production, fertilization rates, tolerance to oxidative stress, and offspring performance. Broodstock reared in biofloc systems (BF) were compared to those in clear water (Without biofloc, WBF) across three salinity levels (18, 28, and 36‰) over a 7-month period. The study also assessed the tolerance of fry reared in biofloc systems to direct transfer to high salinity (36‰) without prior acclimatization. A total of 216 females (initial body weight: 182 ± 1.8 g) and 72 males (initial body weight: 201 ± 0.88 g) were randomly assigned to 18 concrete tanks (2 × 6 × 1 m) to investigate the effects of BFT on spawning performance and larval survival under high-salinity conditions. The findings indicated that appropriate salinity (18‰) in BFT systems positively affected reproductive efficiency, enhanced immunological parameters, and improved growth performance, but elevated salinity levels (36‰) led to reduced reproductive success and hindered growth performance. Florida red tilapia thrive in water quality conditions that are within acceptable limits. High salinity environments led to increased dissolved oxygen but reduced pH, especially in BFT ponds. BFT improved reproductive performance, reduced spawning time, and increased egg production. It also improved hatchability, larval quality, and yolk sac absorption. The BFT broodstock showed higher levels of key proteins (total protein, albumin, and globulin) and improved immune parameters, which helped counteract the negative effects of elevated salinity and enhanced their overall health and stress tolerance. In high-salinity environments, offspring in BFT systems showed higher survival rates and growth rates. In conclusion, BFT improves the reproductive performance, growth, and immune response of Florida red tilapia under high salinity. It enhances egg production, hatchability, and larval survival, while also improving water quality and immune function, making it a sustainable solution for tilapia aquaculture in saline environments.

Boosting Cu ion capture in high-salinity environments with amino-functionalized millispheres.

High salinity in wastewater often hampers the performance of traditional adsorbents by disrupting electrostatic interactions and ion exchange processes, limiting their efficiency. This study addresses these challenges by investigating the salt-promoted adsorption of Cu ions onto amino-functionalized chloromethylated polystyrene (EDA@CMPS) millispheres. The adsorbent was synthesized by grafting ethylenediamine (EDA) onto CMPS, which significantly improved Cu adsorption, achieving nearly three times the capacity in saline solutions (1.65 mmol g-1) compared to non-saline solutions (0.66 mmol g-1). Mechanistic analysis showed that the presence of salts, such as NaCl, promoted the protonation of amino groups on EDA@CMPS, increasing their positive charge and enhancing their affinity for Cu ions. The solution's ionic strength further amplified this protonation, reducing electrostatic repulsion between the adsorbent and the Cu ions, thus improving binding efficiency. Additionally, the increased ionic strength altered Cu speciation, favoring the formation of Cu(NH3)42+ complexes, which were more easily adsorbed. These synergistic effects resulted in faster adsorption kinetics, higher capacity, and improved Cu ion removal, particularly in saline environments. Overall, these findings bridge the gap between material design and functional performance in high-salinity wastewater, offering a promising strategy for efficient heavy metal removal and environmental remediation.

Exploitation of Key Regulatory Modules and Genes for High-Salt Adaptation in Schizothoracine by Weighted Gene Co-Expression Network Analysis

Schizothoracine fishes in saltwater lakes of the Tibetan Plateau are important models for studying the evolution and uplift of the Tibetan Plateau. Examining their adaptation to the high-salt environment is interesting. In this study, we first assembled the RNA-Seq data of each tissue of G. przewalskii, G. selincuoensis, and G. namensis from Qinghai Lake, Selincuo Lake, and Namtso Lake, respectively, obtained by the group previously. After obtaining reliable results, the adaptation of the gills, kidneys, and livers of the three species to the high-salinity environment was assessed by weighted gene co-expression network analysis (WGCNA). Using module eigengenes (ME), 21, 22, and 22 gene modules were identified for G. przewalskii, G. selincuoensis, and G. nemesis, respectively. Functional clustering analysis of genes in the significant association module identified several genes associated with osmolarity-regulated potential KEGG pathways in the gills of three species of Schizothoracine fish. Th17 cell differentiation pathway was up-regulated in the gills of all three species; histocompatibility class 2 II antigen and E alpha (h2-ea) were up-regulated genes in this pathway. Functional clustering analysis of genes in apparently related modules in the kidney unveiled several differential KEGG pathways. The pentose phosphate pathway was up-regulated in the three Schizothoracine fishes, and glucose-6-phosphate dehydrogenase (g6pd) was an up-regulated gene in this pathway. In the livers of the three Schizothorax species, the propanoate metabolism pathway was up-regulated, and succinate-CoA ligase GDP-forming subunit beta (suclg2) was an up-regulated gene in this pathway. The above analyses provide reference data for the adaptation of Schizothorax to high-salt environments and lay the foundation for future studies on the adaptive mechanism of Schizothorax in the plateau. These results partly fill the void in the knowledge gap in the survival adaptations of Schizothoracine fishes to highland saline lakes.

Dehalogenimonas Strain W from Estuarine Sediments Dechlorinates 1,2-Dichloroethane under Elevated Salinity.

Organohalide-respiring bacteria (OHRB) have been found in various environments and play an indispensable role in the biogeochemical cycling and detoxification of halogenated organic compounds (HOCs). Currently, few ORHB have been reported to perform reductive dechlorination under high salinity conditions, indicating a knowledge gap on the diversity of OHRB and the survival strategy of OHRB in saline environments (e.g., estuarine, marine). This study reports the characterization of an enrichment culture dominated by a new Dehalogenimonas population strain W derived from estuarine sediments, which demonstrates the capability to dechlorinate 1,2-dichloroethane (1,2-DCA) to ethene under elevated salinity (≥5.1% NaCl, w/v). Metagenomic and proteomic analyses revealed that the distinctive high-salinity dechlorination of strain W is primarily attributed to a putative reductive dehalogenase (RDase) DdeA, which shares >91.4% amino acid identity with the dihaloeliminating RDase DcpA from other Dehalogenimonas strains. Additionally, ectoine biosynthesis enzymes (EctABC) contribute to the strain's salt tolerance. These findings underscore the potential of OHRB, particularly Dehalogenimonas, to detoxify HOCs in high-salinity environments, such as estuarine and marine ecosystems, by employing compatible solutes as an adaptive mechanism.

Conditioning rice seeds with chitosan to mitigate salt stress

ABSTRACT Rice is considered to be moderately salt-tolerant during germination, development, and ripening stages, and environmentally sensitive during seedling and reproductive stages, which affects seedling emergence and growth, resulting in significant yield losses. Seed conditioning with chitosan has been employed as a useful tool in high-salinity environments with the aim of increasing crop productivity and quality, as well as promoting more sustainable agricultural practices. Therefore, this study aimed to examine the effect of seed conditioning with chitosan on seed germination and rice seedling growth under salinity stress. The experiment consisted of three seeds conditioning and 4 salinity levels, arranged in a completely randomized design with 4 replications. Seeds were sown on germitest paper, and the rolls were placed in a germination chamber (25 ± 2°C and 12 hr photoperiod). Germination and seedling growth parameters were determined. The high salt concentration resulted in reduced growth of rice seedlings, and exogenous application of chitosan at different concentrations and soaking times exerted no apparent adverse effect on germination and growth variables. The attenuating effect of chitosan was observed in the length of the seedlings at all the concentrations utilized. Therefore, evidence indicates that conditioning rice seeds with chitosan might serve as an alternative to mitigate the adverse effects of exposure to stress induced by high salt concentrations.

Intracellular and Extracellular Metabolic Response of the Lactic Acid Bacterium Weissella confusa Under Salt Stress.

Weissella confusa is a member of the lactic acid bacterium group commonly found in many salt-fermented foods. Strains of W. confusa isolated from high-salinity environments have been shown to tolerate salt stress to some extent. However, the specific responses and mechanisms of W. confusa under salt stress are not fully understood. To study the effect of NaCl stress on W. confusa, growth performance and metabolite profiles of the strains were compared between a NaCl-free group and a 35% NaCl-treated group. Growth performance was assessed by measuring viable cell counts and examining the cells using scanning electron microscopy (SEM). Intracellular and extracellular metabolites were analyzed by non-targeted metabolomics based on liquid chromatography-mass spectrometry (LC-MS). It was found that the viable cell count of W. confusa decreased with increasing salinity, and cells could survive even in saturated saline (35%) medium for 24 h. When exposed to 35% NaCl, W. confusa cells exhibited surface pores and protein leakage. Based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, 42 different metabolites were identified in the cells and 18 different metabolites in the culture medium. These different metabolites were mainly involved in amino acid metabolism, carbohydrate metabolism, and nucleotide metabolism. In addition, salt-exposed cells exhibited higher levels of intracellular ectoine and lactose, whose precursors, such as aspartate, L-2,4-diaminobutanoate, and galactinol, were reduced in the culture medium. This study provides insight into the metabolic responses of W. confusa under salt stress, revealing its ability to maintain viability and alter metabolism in response to high NaCl concentrations. Key metabolites such as ectoine and lactose, as well as changes in amino acid and nucleotide metabolism, may contribute to its tolerance to salt. These findings may improve our understanding of the bacterium's survival mechanisms and have potential applications in food fermentation and biotechnology.

Flavonoids from the whole plants of limonium sinense and their anti-inflammatory activity

Medicinal plants in the high salinity and high alkaline environment might possess some special chemical constituents with new skeleton and high bioactivity. In this work, the main chemical constituents of Limonium sinense, namely flavonoids, were comprehensively studied for the first time. A new flavonoid together with five known compounds were isolated from the whole plants of L. sinense. Their structures were determined by the analysis of comprehensive spectroscopic data. All isolates were evaluated for their anti-inflammatory activity. Compound 1 exhibited moderate anti-inflammatory activity on NO production with IC50 value of 20.5 ± 1.3 μM. In addition, 38 flavonoids were identified by UPLC-MS/MS method and 18 reported flavonoids were summarised.

Physiological Function Disturbances and Adaptive Responses in Nile Tilapia (Oreochromis niloticus) Under Different Salinity Stresses

The physiological functions of aquatic organisms are closely linked to changes in environmental salinity. High-salinity environments can disrupt energy metabolism, induce inflammation, and negatively impact normal growth and development. However, aquatic organisms possess self-regulatory mechanisms that can mitigate these impacts to some extent. This study aimed to investigate the adaptive regulatory processes in Nile tilapia (Oreochromis niloticus, Linnaeus, 1758) exposed to high-salinity environments by evaluating metabolic enzyme activities and levels of inflammatory markers. The increased levels of IL-1β and elevated ACP activity suggested that high-salinity conditions (15 and 30 ppt) induced intestinal inflammation. Concurrently, the elevated activities of SOD and GSH, along with decreased SDH activity, pointed to heightened oxidative stress in the brain and a reduced mitochondrial energy supply. Additionally, the adaptive features of intestinal energy metabolism under high-salinity conditions were evident, with adjustments in HK and PK activities mitigating the effects of suppressed PFK activity. Moreover, elevated lipase (LPS) activity in muscle tissue under salinity stress indicated that fat is mobilized to supply energy for muscle activity without affecting muscle protein. In conclusion, salinity stress triggered inflammatory and oxidative stress responses in Nile tilapia, yet the fish exhibited self-regulatory processes in energy metabolism. This study provides a theoretical basis for understanding the adaptive mechanisms of aquatic organisms in stressful environments.

Preparation of nutrient hydrogels with core-shell structure for seed germination and seedling growth in high temperature saline environment.

Drought and soil degradation are the key factors in desertification control. How to improve the utilization efficiency of water and fertilizer has always been the focus of research in desert areas. The conventional hydrogel-loaded fertilizer is not suitable because of the high salinity and large temperature difference in sandy land. Therefore we prepared a novel temperature/pH-responsive core-shell structured hydrogel and loaded urea in three ways: in situ polymerization, encapsulation, and immersion, and germination and seedling growth experiments on Artemisia absinthium and Cabbage (Brassica campestris L. ssp. chinensis Makino) seeds. The results showed that the immersion hydrogel SAP4 (PCP-g-PAA/P(DMAEMA-co-AMPS))/urea had the best repetitive swelling performance, achieving 163.89% of the original water absorption performance after 16 repetitions and the highest nitrogen release of 151.37mg at 40days. For A. desertorum, the treatment group applying the in situ composite hydrogel SAP2 (PCP-g-PAA/P(DMAEMA-co-AMPS)/urea) had the highest germination rate of 70%; for B. campestris, the treatment groups applying SAP2, the encapsulated hydrogel SAP3 (PCP-g-PAA/urea/P(DMAEMA-co-AMPS)) and SAP4 hydrogels had higher germination rates, with SAP3 having a 100% germination rate. This phenomenon suggests that the three urea-loaded temperature/pH-responsive core-shell structured hydrogels we have prepared are very promising as an aid to seed germination and seedling growth in high temperature saline environment.

Differential regulation of magnesium transporters Slc41, Cnnm and Trpm6-7 in the kidney of salmonids may represent evolutionary adaptations to high salinity environments

Magnesium is important for enzymatic reactions and physiological functions, and its intracellular concentration is tightly regulated. Atlantic salmon has the ability to handle large changes in environmental Mg2+ concentration when migrating between freshwater and seawater habitats, making it a relevant model to investigate Mg2+ homeostasis. Parr-smolt transformation (PST) is a life history transition which prepares the freshwater juvenile for the marine environment. The kidney is one of the key organs involved in handling higher salt load in teleosts. Though several key Mg2+ transport families (SLC41, CNNM and TRPM6-7) have recently been identified in mammals and a few fishes, the molecular bases of Mg2+ homeostasis in salmon are not known. We found that all three families are represented in the salmon genome and exhibit a clear conservation of key functional domains and residues. Present study indicates a selective retention of paralogous Mg2+ transporters from the fourth whole genome duplication round (Ss4R) and a differential regulation of these genes, which suggests neo- and/or sub-functionalization events. slc41a1-1, cnnm4a1, -4a2 and trpm7-2 are the main upregulated genes in the kidney during PST and remain high or further increase after exposure to seawater (33 ppt). By contrast, slc41a1-2, -3a, cnnm3-1, and cnnm3-2 are only upregulated after seawater exposure. In addition, slc41a1-1, -2, and trpm7-2 respond when exposed to brackish water (12 ppt), while cnnm3-1 and cnnm3-2 do not, indicating the existence of a lower salinity threshold response for these members. Finally, the response of slc41a1-1, -2 and trpm7-2 in salmon was significantly reduced or completely abolished when exposed to Mg2+-reduced brackish water, while others were not, suggesting they might be specifically regulated by Mg2+. Our results are consistent with previous findings on other euryhaline teleosts and chondrichthyan species, suggesting the existence of common adaptive strategies to thrive in high salinity environments. Concomitantly, salmonid-specific innovations, such as differential regulation and recruitment of family members not previously shown to be regulated in the kidney (Cnnm1 and Cnnm4) of other vertebrates might point to adaptions associated with their very plastic anadromous life cycle.

Degradation mechanism and toxicity assessment of clofibric acid by Fe2+/PS process in saline pharmaceutical wastewater

ABSTRACT A considerable effort has been made to exploring the oxidation of clofibric acid (CA) in advanced oxidation processes (AOPs). However, few studies are available on degradation mechanism and toxicity assessment of CA in saline pharmaceutical wastewater. Here the effect of chlorine on the degradation kinetics of CA by Fe2+/ persulfate (PS) process were studied. Oxidation efficiency, mineralisation, intermediate by-products, reactive oxygen species (ROS) and toxicity assessment were examined. Notably, a high removal efficiency (70.91%) but low mineralisation (20.99%) of CA were observed at pH 3.0 during the Fe2+/PS system. Furthermore, we found Cl− exerted a beneficial impact on CA degradation. However, the degree of CA mineralisation was relatively minor. Under high salinity (100 mM) condition, the primary reactive species within the Fe2+/PS system were SO 4 ⋅ − , OH·, Cl2/HClO, and Fe(IV). Several undesirable chlorinated by-products were formed. A reasonable degradation pathway was proposed. According to the ecological structure–activity relationship (ECOSAR) programme, some transformation products exhibited higher toxicity levels than CA itself in both acute and chronic toxicity assessment, especially in high-salinity environments. These findings elucidate an increased challenges and ecological risk for CA oxidation by Fe2+/PS treatment in saline pharmaceutical wastewater.

Influencing Factors and Ecological Risks of Organochlorine Pesticide Adsorption in Surface Sediments of Qingshui River

ABSTRACT Taking the first-level tributary of Ningxia section of the Yellow River (Qingshui River) as the study area, surface sediment samples were collected during the seasons in 2018. The distribution characteristics, pollution levels, possible sources, influencing factors, and ecological risks of organochloride pesticides (OCPs) in the surface sediments were studied. The detected mean amounts were n.d. ~10.640 (1.474) ng·g−1, and the detection rate was 80.95%. The content (mean values) of Hexachlorocyclohexanes (HCHs), Endosulfan, Chlordane, and Dichlorodiphenyltrichloroethane (DDT) with higher detection amounts and detection rates were n.d. ~0.949 (0.153), n.d. ~1.973 (0.331), n.d. ~0.271 (0.052), and n.d. ~10.583 (0.819) ng·g−1, respectively. The total OCP amounts were detected in Changshantou and Liwang research sections, which have surrounding farmlands and low water flow. The total organic carbon plays a vital role in the residue and distribution of β-HCH and Dieldrin. In a high-salinity environment, the lower-layer sediments had higher adsorption efficiencies for DDT and γ-HCH and the HCH content decreased with the increase in pH. The total nitrogen and phosphorus in sediments were among the controlling factors affecting the distribution of Endosulfan II and p,p’-DDT, respectively, but their effects on Dieldrin only appeared in the spring flood season. Further, a functional model was established with respect to the adsorption amount of various OCPs and the influencing factors. The component analysis results showed that OCPs primarily originated from historical residues; however, only small amounts of Lindane, Dicofol, Endosulfan, and Chlordane compounds have been observed recently in the local environment. Using the low-effect interval and median method for potential ecological risk assessment, Endosulfan was noted to have potential ecological risks, mainly distributed in the middle and lower reaches of the river. The reasons for the potential harm require attention and further research.

Study on the Enhanced Oil Recovery Properties of the Pickering Emulsions for Harsh Reservoirs.

Pickering emulsions stabilized by surfactant-modified SiO2 nanoparticles demonstrate good stability against droplet coalescence, showing application potential for enhanced oil recovery in high-temperature and high-salinity environments. Adjusting the adsorption ratio of surfactant on the nanoparticles significantly affects the wettability of nanoparticles and therefore regulates the microstructure and properties of Pickering emulsions. In this study, a saturated monolayer adsorption occurs at a surfactant-to-nanoparticles ratio of 0.1:1.0%, where an optimal hydrophilic-hydrophobic balance is achieved. However, below or above this ratio, the SiO2 nanoparticles become more hydrophilic with the decreasing or increasing surfactant concentration. Pickering emulsions stabilized by the intermediate wet nanoparticles exhibit the best stability and highest viscosity. Laser confocal scanning microscopy and cryo-scanning electron microscopy reveal that the SiO2 nanoparticles can form a bridge-structure network among the droplets of these emulsions. Microfluidic experiments and sand pack experiments show that Pickering emulsions provide greater permeation resistance than conventional emulsions stabilized solely by surfactant solely. In addition, microscopic experiments show that Pickering emulsions enhance oil recovery by 20% after second waterflooding, compared to a 12% recovery rate with conventional emulsions. It is found that the Pickering emulsions with bridge-structures may be accumulated in and plug channels much larger than their droplets, which results in higher properties of conformance control.

Rethinking nanofiltration membrane design for breaking the trade-off in Li/Mg separation: A comprehensive analysis based on the separation factor-lithium flux (S-JLi) framework

Nanofiltration (NF) membranes are crucial for lithium (Li) recovery from salt-lake brine, but efficient Li/magnesium (Mg) separation remains challenging. This study employs the recently proposed S-JLi (separation factor vs Li flux) framework to evaluate NF membrane performance for Li/Mg separation, addressing limitations in traditional S-A (separation factor vs water permeance) frameworks. Using the Donnan Steric Pore Model with Dielectric Exclusion (DSPM-DE), we systematically investigate how operating conditions, feedwater properties, and membrane characteristics affect Li/Mg separation. Our results reveal that positively charged membranes outperform negatively charged ones, despite experiencing performance drops in high-salinity environments. We identify a trade-off between Li/Mg selectivity and Li flux that cannot be overcome by adjusting single membrane parameters. Multi-parameter synergistic regulation, particularly minimizing effective membrane thickness while optimizing charge density and pore size, emerges as a promising strategy to enhance separation performance. Our numerical simulations align well with experimental data, providing theoretical insights for designing high-performance Li/Mg separation membranes and emphasizing the importance of considering both selectivity and Li recovery in membrane development and evaluation.

Prediction of Corrosion Rate for Carbon Steel Using Regression Model with Commercial LPR Sensor Data

In this study, a model was proposed to predict the corrosion rate (Mils per Year, MPY) of carbon steel in a 3.5% NaCl solution, with the objective of comparing the effectiveness of a commercial LPR sensor against traditional electrochemical methods, using potentiostat-based LPR techniques. The primary factors considered in the experiments were temperature, flow velocity, and pH, tested through a full factorial design to identify the most influential variables. Statistical analysis showed that temperature and flow velocity had a significant effect on corrosion rate, with their interaction having the most substantial impact. In contrast, pH had no statistically significant influence within the tested conditions, likely due to the dominant effects of temperature and flow velocity in the high-salinity environment. The MPY data were validated through Tafel plots, immersion coupon tests, and other electrochemical techniques to confirm the reliability of the measurements. A regression model trained on 54 MPY data points demonstrated high accuracy, achieving a coefficient of determination (R2) of 0.9733. The model also provided reliable predictions for factor combinations excluded from the training dataset. Additionally, scenario-based evaluations highlighted the model’s performance under simulated operating conditions, while revealing challenges related to sensor contamination during long-term use. These findings emphasize the potential of commercial LPR sensors as effective tools for real-time corrosion monitoring and demonstrate the utility of the regression model in marine environments.

Zwitterion-Conjugated Protein Coatings for Enhanced Antifouling in Complex Biofluids: Underlying Molecular Interaction Mechanisms.

Biofouling can cause severe infections, device malfunctions, and failures in diagnostics and therapeutics. Proteins such as bovine serum albumin (BSA) have recently been used as coatings to resist biofouling because they combine surface anchoring and antifouling properties. However, their antifouling effectiveness will significantly deteriorate in complex biofluids with high salinity, limiting their practical applications. In this work, we developed a zwitterion-conjugated protein with enhanced antifouling capability by grafting zwitterionic 2-methacryloyloxyethyl phosphorylcholine (MPC) onto BSA protein via a click reaction. This conjugated protein can easily anchor on various substrates, both inorganic and organic, and exhibits efficient and broad-spectrum fouling resistance to metabolites, proteins, and complex biofluids. Even in the complex fetal bovine serum with higher salinity, the BSA@MPC coating can also maintain 99% fouling resistance robustly, over 6-fold superior to native BSA-coated surfaces in antifouling capability. Direct surface forces measurement reveals that such outstanding antifouling properties of conjugated protein BSA@MPC could be attributed to the stable hydration layer on its surface and the steric repulsion from the antipolyelectrolyte behavior of zwitterionic MPC polymer in the high-salinity environment. Our findings advance the development of protein-based functional materials and provide valuable insights for designing novel antifouling surfaces for marine, food, and bioengineering applications.

Co-precipitation of radium in high–salinity environments: Implications from laboratory experiments and field surveys

The co-precipitation of radium (Ra) with minerals is prevalent in high-salinity environmental systems, with significant implications for geochemical cycling and radiation risk management. This study extensively investigated Ra co-precipitation through both indoor lake experiments and field investigations of saline lakes. 1) In the indoor experiments, calcium ions (Ca2+) concentration remained stable under high-salinity conditions, while barium ions (Ba2+) showed a marked and continuous decline. Ra is less likely to co-precipitate with Ca minerals but has a higher tendency to co-precipitate with Ba sulfates. However, field investigations provided limited support for co-precipitation based on water chemistry. Variations in Ca2+ and Ba2+ with total dissolved solids (TDS) in saline lakes showed no significant correlation, and both calcite and Ba sulfates may precipitate from solution. Thus, water chemistry profiles can provide an initial assessment of potential co-precipitation occurrences. 2) Our study revealed the responses of four Ra species in high-salinity solutions. Within the selected salinity range, the activity of long-lived Ra significantly decreased, and the calculated precipitation rates indicated their co-precipitation with minerals. Although the co-precipitation signals of short-lived Ra may be obscured by desorption and rapid decay, reasonable calculations confirm that they also underwent co-precipitation. The co-precipitation of all Ra species may be attributed to the compression of the anti-ionic diffusion layer around particles under high-salinity conditions. The molar ratio of Ra to Ba in Ba sulfates is significantly higher than that in gypsum and calcite (Ra/Ca), indicating the probably dominant role of Ba sulfates in co-precipitation. Additionally, variations in Ra/Ba ratios and concentrations of Ba and SO₄2− across these systems further elucidate the control exerted by Ba sulfates on Ra co-precipitation. 3) Previous studies have focused primarily on Ra co-precipitation mechanisms in groundwater and controlled experimental systems, while research on other high-salinity environments, such as saline lakes, remains limited. Findings from our saline lake systems further confirm the prevalence of Ra co-precipitation and provide important insights for other high-salinity natural systems (e.g., the Dead Sea) and polluted environments (e.g., mining sites) where Ra co-precipitation constraints may differ from those in saline lakes. In saline lake systems, salinity/TDS regulate mineral saturation indices (SI) by modulating Ra desorption and SO₄2− levels, thereby controlling (Ra, Ba)SO₄ formation, while the effects of pH and temperature are relatively minor. A limitation of this study is the lack of investigation into the influence of fine colloids and potential complexes on Ra species, a discussion that could offer preliminary insights into Ra transport and applications in other high-salinity systems.