High Salinity Environment Research Articles

Correction: Tilapia venturing into high-salinity environments: A cause for concern?

Correction: Tilapia venturing into high-salinity environments: A cause for concern?

Microbial Life in Playa-Lake Sediments: Adapted Structure, Plastic Function to Extreme Water Activity Variations

Saline shallow lakes in arid and semi-arid regions frequently undergo drying episodes, leading to significant variations in salinity and water availability. Research on the impacts of salinity and drought on the structure and function of biofilms in hypersaline shallow lakes is limited. This study aimed to understand the potential changes of biofilms in playa-lake sediments during the drying process. Sediments were sampled at different depths (surface, subsurface) and hydrological periods (wet, retraction, and dry), which included a decrease in water activity (aw, the availability of water for microbial use) from 0.99 to 0.72. aw reduction caused a greater effect on functional variables compared to structural variables, indicating the high resistance of the studied biofilms to changes in salinity and water availability. Respiration and hydrolytic extracellular enzyme activities exhibited higher values under high aw, while phenol oxidase activity and prokaryote biomass increased at lower aw. This shift occurred at both depths but was more pronounced at the surface, possibly due to the more extreme conditions (up to 0.7 aw). The increased levels of extracellular polymeric substances and carotenoids developed at low aw may help protect microorganisms in high salinity and drought environments. However, these harsh conditions may interfere with the activity of hydrolytic enzymes and their producers, while promoting the growth of resistant prokaryotes and their capacity to obtain C and N sources from recalcitrant compounds. The resilience of biofilms in hypersaline lakes under extreme conditions is given by their resistant biochemichal structure and the adaptability of their microbial functioning.

Study on the differences in microscopic oil displacement effects and action mechanisms of different rhamnolipid systems

Rhamnolipids are a class of anionic glycolipid surfactants produced through microbial metabolism. As a widely researched biosurfactant, rhamnolipids possess several advantages over traditional chemical surfactants, including non-toxicity, eco-friendliness, biodegradability, and biocompatibility, particularly in the context of microbial oil recovery applications. This class of surfactants enhances oil recovery by reducing the interfacial tension between oil and water, emulsifying residual oil, and modifying the wettability of rock surfaces. Furthermore, rhamnolipids maintain stability in high-temperature and high-salinity environments. However, rhamnolipids derived from different fermentation substrates exhibit variations in structure, composition, and properties, resulting in distinct displacement effects and mechanisms of action. This study focuses on two types of rhamnolipids: typical rhamnolipid and high-yield rhamnolipid, which are fermented using glycerol and rapeseed oil, respectively. Based on the characteristics of the target heavy oil reservoir, micromodels were designed and manufactured to conduct microfluidic experiments. The results obtained from imaging and video recording were analyzed qualitatively and quantitatively to explore the differences in effects and mechanisms between the two rhamnolipid systems. Results indicate that typical rhamnolipid increased recovery by 4.41% through delayed mechanisms involving wettability modification and residual oil emulsification. Conversely, high-yield rhamnolipid demonstrates an immediate effect by reducing interfacial tension, resulting in a recovery increase in 5.68%. According to the observed experimental phenomena and analytical trends, the conclusions evaluate the production increase, clarify the differences in mechanisms of action, and enhance the microscopic understanding of these surfactants. These findings provide directions for future investigations and serve as a reference for the design of related schemes.

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 151.37 mg at 40 days. 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.

Insights into the Epigenetic Basis of Plant Salt Tolerance.

The increasing salinity of agricultural lands highlights the urgent need to improve salt tolerance in crops, a critical factor for ensuring food security. Epigenetic mechanisms are pivotal in plant adaptation to salt stress. This review elucidates the complex roles of DNA methylation, histone modifications, histone variants, and non-coding RNAs in the fine-tuning of gene expression in response to salt stress. It emphasizes how heritable changes, which do not alter the DNA sequence but significantly impact plant phenotype, contribute to this adaptation. DNA methylation is notably prevalent under high-salinity conditions and is associated with changes in gene expression that enhance plant resilience to salt. Modifications in histones, including both methylation and acetylation, are directly linked to the regulation of salt-tolerance genes. The presence of histone variants, such as H2A.Z, is altered under salt stress, promoting plant adaptation to high-salinity environments. Additionally, non-coding RNAs, such as miRNAs and lncRNAs, contribute to the intricate gene regulatory network under salt stress. This review also underscores the importance of understanding these epigenetic changes in developing plant stress memory and enhancing stress tolerance.

Practical Remediation of Hg-Contaminated Groundwater by MoS2: Batch and Column Tests.

Trace mercury contamination in groundwater poses a serious threat to ecological systems and human health. The kinetics and isotherms of MoS2 (MS) for Hg removal were studied in batch tests under an unfavorable high salinity and low mercury environment. Flower-like MS with nanosheets can effectively remove Hg in the groundwater matrix, with a shorter equilibrium time (3 h), superior removal efficiency (94.26%), excellent distribution coefficient (5.69 × 106 mL g-1), and higher maximum adsorption capacity (926.10 ± 165.25 mg g-1). Furthermore, the Adams-Bohart model (R2 = 0.9052-0.9416) can accurately describe the dynamic interception process of the initial stage (≤40 PVs), and the Yan model (R2 = 0.9765-0.9941) depicts the whole process (140 PVs) of MS in a fixed column well. A higher dosage of m, but lower C0 and νp facilitate the interception efficiency in column tests. Based on the characterizations of X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), which were used to simultaneously consider the species of Hg and the groundwater matrix, surface complexation, electrostatic attraction, ion exchange, and precipitation is a plausible interfacial adsorption mechanism of MS for mercury. The excellent performance demonstrates that MS with nanosheets is a promising candidate for the PRB remediation of trace Hg in saline groundwater.

Chemical Constituents from the Whole Plants of Limonium sinense and Their in vitro Anti-inflammatory Activity.

The Yellow River Delta possesses lots of characteristic medicinal plants due to its high salinity and high alkaline environment and Limonium sinense is an iconic plant. However, there are very few studies on L. sinense and its chemical constituents have not been investigated in recent ten years. In the present study, the chemical constituents and bioactivities of L. sinense were fully studied for the first time. UPLC-MS/MS method combined with database comparison identified 109 compounds mainly including flavonoids, alkaloids and polyphenols. In addition, the potential bioactivities of L. sinense were considerated as anti-inflammatory, anti-oxidative, anti-tumor, hepatoprotective and hpyerglycemic activities based on these identified compounds and their related literature. Furthermore, four derivatives of 12-oxo-phytodienoic acid and butenolide including two new ones (1 and 2) were isolated from the whole plants of L. sinense. Their structures, including the absolute configurations, 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 with IC50 value of 37.5±1.2 μM on NO production level.

HaloClass: Salt-Tolerant Protein Classification with Protein Language Models.

Salt-tolerant proteins, also known as halophilic proteins, have unique adaptations to function in high-salinity environments. These proteins have naturally evolved in extremophilic organisms, and more recently, are being increasingly applied as enzymes in industrial processes. Due to an abundance of salt-tolerant sequences and a simultaneous lack of experimental structures, most computational methods to predict stability are sequence-based only. These approaches, however, are hindered by a lack of structural understanding of these proteins. Here, we present HaloClass, an SVM classifier that leverages ESM-2 protein language model embeddings to accurately identify salt-tolerant proteins. On a newer and larger test dataset, HaloClass outperforms existing approaches when predicting the stability of never-before-seen proteins that are distal to its training set. Finally, on a mutation study that evaluated changes in salt tolerance based on single- and multiple-point mutants, HaloClass outperforms existing approaches, suggesting applications in the guided design of salt-tolerant enzymes.

Enhanced bioremediation of saline azo dye effluents using PersiLac3: A thermo-halotolerant laccase from a tannery metagenome

Large quantities of recalcitrant azo dye wastewater represent an important environmental issue, owing to their toxicity and the difficulty of their treatment under hypersaline conditions. By maintaining high activity under salt-rich conditions, salt-tolerant laccases offer a promising solution for the effective breakdown of toxic azo dyes, making them indispensable for the sustainable treatment of industrial wastewater. This study explored the identification and application of a thermo-halotolerant laccase, PersiLac3, for bioremediation of azo dye wastewater under high-salt conditions typical of textile effluents. The broad substrate oxidation potential of PersiLac3 was assessed across diverse temperatures, pH levels, and challenging conditions, such as high salt levels, and in the presence of organic solvents and inhibitors. Remarkably, PersiLac3 showed enhanced activity (112.25 %) in 3 M NaCl, highlighting its superior ability to adapt to saline conditions. Kinetic studies of PersiLac3 indicated high efficiency and affinity for its substrate at saline concentrations ranging from 1 to 6 M NaCl. PersiLac3 effectively decolorized the Congo red dye (82.9 %) in highly concentrated solutions (5000 mg/L) within 15 min, and its performance was further improved in the presence of wastewater-relevant ions, achieving 92.3 % dye removal. Monitoring real wastewater treatments, PersiLac3 reduced optical density, underscoring its potential for application in the bioremediation of dye-laden and saline wastewater streams. The adaptability of PersiLac3 to harsh, high-salinity environments, coupled with its rapid dye decolorization efficiency, is an innovative and powerful tool for addressing environmental pollution challenges and advancing waste treatment methodologies.

Physicochemical characteristics and nutritional value of safflower oil: A potential sustainable crop for Egypt

Background: The Increasing demand for sustainable and economical non-traditional edible oils, as alternatives to common oils is pivotal to bridge the edible oils gap, coupled with negative impacts of climate change on the agroecological settings for common oilseed crop productivity. Safflower, being one of the fast-growing medicinal oilseeds crops rich in polyunsaturated fatty acids, known as the “king of linoleic acid”, exhibits resilience to adverse environmental conditions such as high temperatures, drought, salinity, and marginal environments. Aims: This study aimed to comprehensively assess the physicochemical characteristics and lipid nutritional indices of safflower oil to validate its potential for expanded cultivation in Egypt. Materials and Methods: Safflower oil was extracted from seeds of two spineless varieties cultivated in Egypt. The oil was subjected to proximate analysis, physicochemical characterization, fatty acid profile determination, and α-tocopherol content analysis. Additionally, a frying stability test was carried out for safflower oil and its blends with soybean oil in different ratios, monitoring changes in free fatty acid, peroxide value, and total polar compounds. Lipid nutritional indices were calculated to assess the oil’s health-promoting properties. Results: Safflower oil exhibited similar proximate composition and physicochemical characteristics to sunflower oil. The fatty acid profile of safflower oil was comparable to sunflower oil, with a lower oleic acid content and a higher linoleic acid content. Furthermore, safflower oil demonstrated satisfactory stability during the frying process. Lipid nutritional indices calculated based on the fatty acid profile revealed that safflower oil is a valuable source of ω-6 fatty acids. The oil exhibited favorable values for atherogenicity index (AI), thrombogenicity index (TI), hypocholesterolemic / hypercholesterolemic (HH), health-promoting index (HPI), and possessed strong antioxidant properties due to its high α-tocopherol content. Conclusion: The findings of this study support the potential of safflower oil as a promising non-traditional edible oil, suitable for expanded cultivation in Egypt. Its favorable nutritional profile and stability make it a valuable addition to the dietary landscape. Keywords: Carthamus tinctorius L., safflower oil, edible oil gap, lipid nutritional indices, frying stability, non-traditional edible oils.

Understanding of Plant Salt Tolerance Mechanisms and Application to Molecular Breeding.

Soil salinization is a widespread hindrance that endangers agricultural production and ecological security. High salt concentrations in saline soils are primarily caused by osmotic stress, ionic toxicity and oxidative stress, which have a negative impact on plant growth and development. In order to withstand salt stress, plants have developed a series of complicated physiological and molecular mechanisms, encompassing adaptive changes in the structure and function of various plant organs, as well as the intricate signal transduction networks enabling plants to survive in high-salinity environments. This review summarizes the recent advances in salt perception under different tissues, physiological responses and signaling regulations of plant tolerance to salt stress. We also examine the current knowledge of strategies for breeding salt-tolerant plants, including the applications of omics technologies and transgenic approaches, aiming to provide the basis for the cultivation of salt-tolerant crops through molecular breeding. Finally, future research on the application of wild germplasm resources and muti-omics technologies to discover new tolerant genes as well as investigation of crosstalk among plant hormone signaling pathways to uncover plant salt tolerance mechanisms are also discussed in this review.

A 3D aerogel evaporator for efficient solar interfacial evaporation: Breaking through the upper limit of steam production rate

Solar desalination is the most effective way to obtain clean and cheap fresh water. However, its lower upper limit of steam production rate limits its development and practical applications. In this paper, a microcrystalline cellulose aerogel composite Mo2C evaporator (MCAM) was prepared by combining Mo2C with microcrystalline cellulose aerogel (MCA). The evaporator consists of MCAM photothermal layer, polyurethane (PU) sponge insulation layer and one-dimensional water channel. Mo2C has high-light absorption efficiency. At the same time, the vertical channel inside the MCA makes the incident light be reflected and absorbed for many times inside. Benefiting from the synergistic effect of the vertical channel of MCA and the light absorption ability of Mo2C, MCAM obtained a high light absorption efficiency of 96.96 %. The interaction between the MCAM evaporator and water can reduce the evaporation enthalpy, thereby breaking the upper limit of the steam generation rate. Therefore, the evaporator achieved a steam production rate of 1.92 kg⋅m−2⋅h−1 and an energy utilization efficiency of 118.2 %. In addition, MCAM shows excellent salt tolerance and self-discharging salt ability, which ensures its stable operation in high-salinity environment. Besides its high efficiency, MCAM has significant purification effect on simulated seawater, heavy metal wastewater, and organic wastewater. This study provides a new strategy for further improving the steam production rate of the solar interface evaporator.

Giant gateable thermoelectric conversion by tuning the ion linkage interactions in covalent organic framework membranes

Efficient energy conversion using ions as carriers necessitates membranes that sustain high permselectivity in high salinity conditions, which presents a significant challenge. This study addresses the issue by manipulating the linkages in covalent-organic-framework membranes, altering the distribution of electrostatic potentials and thereby influencing the short-range interactions between ions and membranes. We show that a charge-neutral covalent-organic-framework membrane with β-ketoenamine linkages achieves record permselectivity in high salinity environments. Additionally, the membrane retains its permselectivity under temperature gradients, providing a method for converting low-grade waste heat into electrical energy. Experiments reveal that with a 3 M KCl solution and a 50 K temperature difference, the membrane generates an output power density of 5.70 W m−2. Furthermore, guided by a short-range ionic screening mechanism, the membrane exhibits adaptable permselectivity, allowing reversible and controllable operations by finely adjusting charge polarity and magnitude on the membrane’s channel surfaces via ion adsorption. Notably, treatment with K3PO4 solutions significantly enhances permselectivity, resulting in a giant output power density of 20.22 W m−2, a 3.6-fold increase over the untreated membrane, setting a benchmark for converting low-grade heat into electrical energy.

Unveiling the impacts of salts on halotolerant bacteria during filtration: A new perspective on membrane biofouling formation in MBR treating high-saline organic wastewater

In recent decades, membrane bioreactor (MBR) has been prevalently employed to treat high-saline organic wastewater, where the halotolerant microorganisms should be intensively utilized. However, limited works were devoted to investigating the biofouling characteristics from the perspective of the relationship between halotolerant bacteria and salts. This work filled the knowledge gap by exploring the biofouling formation mechanisms affected by high salinity. The results showed that the amount of negative charge on halotolerant bacteria surface was significantly reduced by high content of NaCl, probably leading to the obvious cell agglomeration. Despite the normal proliferation, the halotolerant bacteria still produced substantial EPS triggered by high salinity. Compared with the case of control without salt addition, the enhanced biofouling development was observed under high-saline conditions, with the fouling mechanism dramatically transformed from cake filtration to intermediate blocking. It was inferred that the halotolerant bacteria initially adhered on membrane created an extra filter layer, which contributed to the subsequent NaCl retention, resulting in the simultaneous occurrences of pore blockage and cake layer formation because of NaCl deposition both on membrane pores as well as on biofilm layer. Under high-saline environment, remarkable salt crystallization occurred on the biofilm layer, with more protein secreted by the attached halotolerant bacteria. Consequently, the potential mechanisms for the enhanced biofouling formation influenced by high salinity were proposed, which should provide new insights and enlightenments on fouling control strategies for MBR operation when treating high-saline organic wastewater.

Characterization of a Halostable Metalloprotease from the Halophilic Bacterium Bacillus clausii J1G-0%B

Protein plays a crucial role as a biocatalyst in various industries, particularly in breaking down proteins into amino acids. The demand for proteases capable of functioning under extreme conditions, such as high salinity, temperature, and pH, is increasing. To address this, the exploration of bacteria that produce stable proteases in such environments is essential. Bacillus clausii J1G-0%B, a halophilic bacterium isolated from Madura salt ponds, thrives in salinity levels of 0-20% NaCl. This study aims to obtain and characterize the protease produced by Bacillus clausii J1G-0%B, focusing on its activity and stability under extreme conditions. The research involved screening, production, and purification of the protease using ammonium sulfate fractionation and dialysis. Protease activity was measured using the Kunitz method, and protein content was determined using the Lowry method. Characterization included optimizing enzymatic conditions (pH, temperature, NaCl concentration), identifying metalloprotease types, and analyzing enzyme kinetics and thermodynamics. The study successfully produced protease using a halophilic medium with casein and 5% NaCl. After 96 hours of incubation, the protease exhibited a specific activity of 654.737 U/mg. Optimal activity was observed at pH 7, 50°C, and 10% NaCl, with stability between 2.5% and 15% NaCl concentration. Enzyme kinetics revealed a high affinity for casein, with a KM value of 0.164 mg/mL and Vmax of 13.182 µmol/mL·min. Thermodynamic analysis indicated high stability, as shown by a positive ΔGi value (+105.84 kJ/mol), a low inactivation constant (ki = 0.0031 min-1), and a long half-life (t½ = 223.548 minutes). EDTA chelation tests confirmed that the protease is a metalloprotease. The halostable protease from Bacillus clausii J1G-0%B shows significant potential for industrial applications and bioremediation in high-salinity environments.

In vitro Bioaccesibility of Phenolic Compounds from the Halophytes Suaeda Edulis and Suaeda Esteroa: Opportunity for the Development of Novel Foods

Halophytic plants grow in high salinity environments and present phytochemicals with antioxidant properties, such as phenolic compounds; due to the uncertain availability of healthy foods, there is a growing interest in their nutritional potential. However, their bioactive compounds with beneficial health effects are limited in their bioaccessibility. The objective of this study was to subject S. edulis and S. esteroa to an in vitro digestion process to evaluate the bioaccessibility and total antioxidant capacity of phenolic compounds during three phases of digestion. We determined phenolic compounds, flavonoids, and antioxidant capacity by colorimetric methods and phenolic composition by UHPLC-DAD. Total phenols, total flavonoids, and total antioxidant capacity by DPPH and TEAC in the three phases of digestion (oral, gastric, and intestinal) of S. esteroa were higher than in S. edulis, founding 4.84 % higher in total phenol content, and 0.05 % in total flavonoid content; also, and 28.94 and 23.93 % higher in total antioxidant capacity by DPPH and TEAC, respectively in the intestinal digestion phase. The bioaccessibility of S. edulis was higher than in S. esteroa; the intestinal was the phase reflecting more bioaccessible compounds. The bioaccessibility percentages of total phenols and flavonoids were 590.16 and 1012.93 %, and the percentage recovery of total antioxidant capacity by DPPH and TEAC were 181.37 and 139.74 %. We identified phenolic acids ferulic, p-Coumaric, and synaptic (hydroxycinnamic), gallic and protocatechuic (hydroxybenzoic), the flavonoids catechin (flavan-3-oles), myricetin and ruthin (flavonols), naringenin and naringin (flavonones). S. esteroa presented bioactive compounds in higher concentrations than S. edulis due to the stress imposed by its habitat; nevertheless, the determined bioactive compounds of S. edulis showed a higher bioaccessibility because it was managed under local improvement.

Super-Elastic and Temperature-Tolerant Hydrogel Electrodes for Supercapacitors via MXene Enhanced Ice-Templating Synthesis.

Developing flexible energy storage devices with good deformation resistance under extreme operating conditions is highly desirable yet remains very challenging. Super-elastic MXene-enhanced polyvinyl alcohol/polyaniline (AMPH) hydrogel electrodes are designed and synthesized through vertical gradient ice templating-induced polymerization. This approach allows for the unidirectional growth of polyaniline (PANI) and 2D MXene layers along the elongated arrayed ice crystals in a controlled manner. The resulting 3D unidirectional AMPH hydrogel exhibits inherent stretchability and electronic conductivity, with the ability to completely recover its shape even under extreme conditions, such as 500% tensile strain, 50% compressive strain. The presence of MXene in the hydrogel electrode enhances its resilience to mechanical compression and stretching, resulting in less variation in resistance. AMPH has a specific capacitance of 130.68 and 88.02mFcm-2 at a current density of 0.2 and 2mAcm-2, respectively, and retains 90% and 70% of its original capacitance at elongation of 100% and 200%, respectively. AMPH-based supercapacitors demonstrate exceptional performance in high salinity environments and wide temperature ranges (-30-80°C). The high electrochemical activity, temperature tolerance, and mechanical robustness of AMPH-based supercapacitor endow it promising as the power supply for flexible and wearable electronic devices.

Revolutionizing Tetracycline Hydrochloride Remediation: 3D Motile Light-Driven MOFs Based Micromotors in Harsh Saline Environments.

Traditional light-driven metal-organic-frameworks (MOFs)-based micromotors (MOFtors) are typically constrained to two-dimensional (2D) motion under ultraviolet or near-infrared light and often demonstrate instability and susceptibility to ions in high-saline environments. This limitation is particularly relevant to employing micromotors in water purification, as real wastewater is frequently coupled with high salinity. In response to these challenges, ultrastable MOFtors capable of three-dimensional (3D) motion under a broad spectrum of light through thermophoresis and electrophoresis are successfully synthesized. The MOFtors integrated photocatalytic porphyrin MOFs (PCN-224) with a photothermal component made of polypyrrole (PPy) by three distinct methodologies, resulting in micromotors with different motion behavior and catalytic performance. Impressively, the optimized MOFtors display exceptional maximum velocity of 1305±327µms-1 under blue light and 2357±453µms-1 under UV light. In harsh saline environments, these MOFtors are not only maintain high motility but also exhibit superior tetracycline hydrochloride (TCH) removal efficiency of 3578±510mgg-1, coupling with sulfate radical-based advanced oxidation processes and peroxymonosulfate. This research underscores the significant potential of highly efficient MOFtors with robust photocatalytic activity in effectively removing TCH in challenging saline conditions, representing a substantial advancement in applying MOFtors within real-world water treatment technologies.

Electrochemical lithium extraction from high Mg/Li brine using LiMn2O4-Zn mixed-Ion battery

In China, 80 % of lithium resources are in the salt lakes of the Tibetan Plateau, although the Mg2+/Li+ ratios in them are too high, limiting the development of China’s lithium extraction industry from the salt lakes. This study investigates the potential of the LiMn2O4-Zn cell system for lithium extraction from brines with high Mg2+/Li+ ratios. The system demonstrates excellent selectivity for Li+ and efficiently extracts Li+ even in brines with Mg2+/Li+ ratios as high as 100:1 (wt%). The system operates stably at various brine concentrations, particularly in high-salinity environments. The study also investigates the kinetic performance of the LMO-Zn system, revealing optimal performance at high Li+ concentrations and moderate current densities. The LiMn2O4-Zn cell system presents a promising approach for lithium extraction from brines, offering high selectivity, reversibility, and adaptability.

Enhancing structural strength and water retention of crosslinked polyacrylamide gel with the T-ZnOw

Crosslinked polyacrylamide gel serves as an effective plugging material, crucial for preventing water/gas channeling in reservoirs and enhancing the swept volume and oil recovery. However, its practical application encounters a significant challenge in maintaining long-term stability of strength and volume, particularly under high temperatures. This study investigates the reinforcement of polyacrylamide gel with three-dimensional (3D) nanomaterials, specifically tetra-needle-like zinc oxide whiskers (T-ZnOw), to enhance its structural stability and bound water content. The stress sweep tests showed that the addition of 0.15 wt% T-ZnOw increased the maximum elastic modulus of the gel to 28.5 Pa, representing a 51.2 % improvement compared to before the addition. After 60 days of high-temperature aging at 130 °C, the T-ZnOw strengthened gel still maintained an elastic modulus of 21.8 Pa. With increasing T-ZnOw concentration, the yield point of the gel increased from 4.74 Pa to 9.57 Pa, the anti-deformation of the gel has significantly increased. The stability test results in high salinity water indicate that at a salinity of 150,000 mg/L, the dehydration rate of the strengthened gel is less than 5 %, with an elastic modulus retention rate exceeding 88 %. Furthermore, thermodynamic testing confirms the enhanced thermal degradation resistance and water retention capacity of the gel. Under reservoir temperature conditions, the T-ZnOw strengthened gel exhibits a weight loss of less than 3 %. Additionally, the inclusion of T-ZnOw results in an increase in the bound water capacity index from 4.65 to 12.28. In conclusion, the integration of T-ZnOw into the polyacrylamide gel network not only enhances its mechanical performance and water retention under high-temperature conditions but also demonstrates superior stability in high-salinity environments. This innovative material shows significant potential for improving oil recovery rates in high-temperature reservoirs and can be applied to other high-temperature underground scenarios such as geothermal development and CO2 utilization and storage.