Salt Deposits Research Articles

Resource recovery from acid mine drainage in membrane distillation crystallization

Acid mine drainage (AMD) remains a global threat with no exception to South African water bodies and the environment. It promotes environmental challenges with emerging concerns on water security and drinking water pollution. This study evaluated membrane distillation crystallization (MDC) towards resource recovery from AMD. To ensure high process performance, polyvinylidene fluoride (PVDF) membranes evaluated in the current study were modified using hydrophobic nanoparticle additives and compared with PTFE-20 reference membrane. The produced permeate flux of PTFE-20 reference membranes and M4 (fSiO2NPs-modified membrane) were 2.426 kg m-2·h-1 and 1.459 kg m-2·h-1, respectively. Similarly, salt rejections were 99.96% and 97.52%, respectively. Based on single crystal x-ray diffraction and scanning electron microscopy analysis, MDC predominantly produced monoclinic gypsum (CaSO4.2H2O) with the C2/c space group. Also, crystal properties obtained in fSiO2NPs-modified and PTFE-20 reference membranes were comparable. Though a considerable amount of gypsum was obtained, membrane surfaces were characterized by traces of salt deposit, with possible membrane scaling leading to performance deterioration. The permeate conductivity increased rapidly at the highest water recovery factor, indicating membrane wetting caused by scaling.

IMPACT OF CHLORIDE AND LEAD ION CONTENT IN OPEN WATER SOURCES IN KYZYLORDA REGION ON POPULATION’S CANCER INCIDENCE

Relevance: In 2004-2013, the cumulative cancer incidence was about 200 cases per 100 thousand in Kazakhstan, while in the disaster area of Aral Sea – about 225 cases per 100 thousand. For comparison, cancer incidence in the prosperous region of Karaganda was 140 cases per 100,000 population. As of 2021, the incidence of colorectal cancer in Kyzylorda was 17.73 compared to 5.81 per 100,000 population in 2015.
 Factors of the surrounding macro- and microenvironment are trigger factors for tumor initiation. Salt deposits of the dried Aral Sea in the form of solonchaks spread to the territory of the entire Kyzylorda region. Pesticides and process water have been discharged into rivers for many years, which has led to the accumulation of heavy metal salts in water and soil on the banks of the rivers and in the place of the dried-up Aral Sea, which in turn can affect the increase in cancer incidence.
 The study aimed to study the dependence of cancer incidence on water pollution by ions of chlorine and lead in open water bodies in the Kyzylorda region.
 Methods: Analysis of cancer incidence in 2021 by localization: intestines, stomach, sarcomas, lungs, and melanomas in the Kyzylorda region. Determination of the content of chlorine ions by titration with silver nitrate, spectrophotometric determination of lead ions in the open water sources. Comparative correlation analysis of the concentration of chlorine ions and lead with cancer incidence in this region.
 Results: The maximum permissible chlorine and lead ions concentrations in all studied open water sources of the Kyzylorda region exceeded the norm by 1.024-20.26 times and 1.4-14.1 times, respectively. The presence of chlorides in the water increased intestine cancer incidence by 17% with an approximation certainty of 0.38. The presence of lead in water increased the incidence of melanomas by 22%, with an approximation certainty of 0.79. The correlation coefficient was r=0.618; p=0.07 for exceeding chlorides’ MPC and bowel cancer incidence.
 Conclusion: Heavy metals like lead in water samples in regions with increased cancer incidence indicate a co-dependent relationship of these factors. Pollutants such as chlorides and lead increase intestine cancer and melanoma incidence.

Rhinolith in a 19-Year-Old Girl: A Case Report of a Rare Condition

Rhinolith means formation of stone in the nasal cavity which is an uncommon cause of nasal obstruction. It occurs due to mineralization of an endogenous or exogenous nidus with deposition of mineral salts, calcium and magnesium phosphates. Patients usually present with foul smelling/ purulent nasal discharge, nasal bleeding, nasal obstruction, halitosis, tooth ache or palatal perforation. Endoscopic removal of rhinolith leads to less morbidity which the treatment of choice. We report a case of 19-year-old female with rhinolith on the right nasal cavity which was removed endoscopically.

Thermo-optical performance of building glass under salt sedimentation

The phenomenon of salt sedimentation on the building glass surface occurs in coastal salt-fog climates, leading to the changes in surface heat transfer characteristics and optical properties, which affects the indoor environment and gradually reduces building energy performance. Regrettably, there remains a paucity of research concerning the impact of salt sedimentation on the thermal and optical performances of building glass. This study investigated the salt sedimentation features of building glass using an indoor accelerated test, and explored the relationships between surface heat transfer coefficients, optical properties and salt sedimentation. As the spray duration grew, the sedimented salt stains appeared more dispersed and less dense, but their dimensions increased, exhibiting an exponential growth tendency. The salt sedimentation per unit area grew logarithmically with the spray duration, with the magnitudes being 14.4 to 40.0 mg/m2 and 15.6 to 44.3 mg/m2 under 5% and 10% brine concentration conditions, respectively. The convection heat transfer coefficient (CHTC) and radiative heat transfer coefficient (RHTC) showed a linear monotonic increase with the salt sedimentation, in contrast to the control condition, with the maximum growth rates reaching 178.7% and 97.2%, respectively. The extended CHTC model could be used to calculate the CHTC regarding the impact of salt sedimentation and wind speed. The entire solar spectral transmittance and reflectance was affected by salt sedimentation, and the visible light transmittance, reflectance, hemispherical emissivity, and shading coefficient of low-E and clear glasses all decreased linearly with the increase of salt sedimentation.

Construction of a biomimetic wood structure with cellulose nanofiber/molybdenum disulfide hybrid aerogel for highly-efficient solar-driven interfacial evaporation

Solar-driven interfacial water evaporation is a promising solution to water scarcity and pollution problems because it can efficiently convert solar energy into thermal energy and produce sustainable clean water. In this work, inspired by the multi-channel structure in the xylem of plants, cellulose nanofibers (CNF) and molybdenum disulfide (MoS2) nanosheets were selected to construct CNF/MoS2 nanosheets aerogel (CMoA) with vertical pores by directional freeze-drying method. Then we utilized the aerogel as an interfacial solar evaporator. The super-hydrophilic and internal vertical pore structure of this evaporator gives CMoA a high capacity to store and transport water, with a water evaporation rate of 1.81 ± 0.06 kg·m−2·h−1 under 1 sun. The vertical pore structure and the strong ability to transport water of the evaporator also enable the salt on the evaporator surface to diffuse into the bulk water in time, without causing salt deposition. Therefore, CMoA has high salt resistance and stability and can achieve fast evaporation even in high-concentration salt water. In addition, CMoA can also produce water at a rate of up to 10.3 kg·m−2 per day in the outdoor environment. By combining the natural bio-based material CNF with the biomimetic wood structure of aerogel, CMoA has a facile water transport process similar to that of plants. Moreover, our CMoA is a monolayer structure, which makes the preparation process simple and less costly. These multiple advantages make CMoA a promising application for future practical desalination work.

IMPACT OF CHLORIDE AND LEAD ION CONTENT IN OPEN WATER SOURCES
 IN KYZYLORDA REGION ON POPULATION’S CANCER INCIDENCE

Relevance: In 2004-2013, the cumulative cancer incidence was about 200 cases per 100 thousand in Kazakhstan, while in the disaster area
 of Aral Sea – about 225 cases per 100 thousand. For comparison, cancer incidence in the prosperous region of Karaganda was 140 cases per
 100,000 population. As of 2021, the incidence of colorectal cancer in Kyzylorda was 17.73 compared to 5.81 per 100,000 population in 2015.
 Factors of the surrounding macro- and microenvironment are trigger factors for tumor initiation. Salt deposits of the dried Aral Sea in the
 form of solonchaks spread to the territory of the entire Kyzylorda region. Pesticides and process water have been discharged into rivers for
 many years, which has led to the accumulation of heavy metal salts in water and soil on the banks of the rivers and in the place of the dried-up
 Aral Sea, which in turn can affect the increase in cancer incidence.
 The study aimed to study the dependence of cancer incidence on water pollution by ions of chlorine and lead in open water bodies in the
 Kyzylorda region.
 Methods: Analysis of cancer incidence in 2021 by localization: intestines, stomach, sarcomas, lungs, and melanomas in the Kyzylorda
 region. Determination of the content of chlorine ions by titration with silver nitrate, spectrophotometric determination of lead ions in the open
 water sources. Comparative correlation analysis of the concentration of chlorine ions and lead with cancer incidence in this region.
 Results: The maximum permissible chlorine and lead ions concentrations in all studied open water sources of the Kyzylorda region exceeded the norm by 1.024-20.26 times and 1.4-14.1 times, respectively. The presence of chlorides in the water increased intestine cancer incidence
 by 17% with an approximation certainty of 0.38. The presence of lead in water increased the incidence of melanomas by 22%, with an approximation certainty of 0.79. The correlation coefficient was r=0.618; p=0.07 for exceeding chlorides’ MPC and bowel cancer incidence.
 Conclusion: Heavy metals like lead in water samples in regions with increased cancer incidence indicate a co-dependent relationship of
 these factors. Pollutants such as chlorides and lead increase intestine cancer and melanoma incidence

Lipid Biosignatures From SO4‐Rich Hypersaline Lakes of the Cariboo Plateau

AbstractModern and ancient hypersaline brines have been identified across the solar system, but the habitability of these environments remains unknown. Here, we evaluate organic matter (OM) production in MgSO4 and Na2CO3 rich hypersaline lakes whose chemistries resemble deposits on Mars such as those identified in Jezero crater. We focus our analysis on lipid biomarkers including fatty acids, alkanes, and ether‐bound lipids in modern brines, salt deposits, and surface sediments. We also report total organic carbon (TOC), carbon/nitrogen (C/N) ratios, and bulk OC (δ13C and δ15N) isotopes to contextualize the lipid biomarker data. In all lakes, the predominant biosignatures include midchain (12 < C < 23) fatty acids and alkanes suggesting microbial origin. Sediments also incorporate a greater diversity of lipids. Ether‐bound lipids derived from archaea and bacteria constitute a minor but measurable fraction of the lipids. This result contrasts with typical findings from other studies with NaCl brines which contain significant archeal biomass. TOC concentrations in all sediments are high, ranging from 0.7% to 12% with sulfate‐rich sediments having the highest concentrations. The isotopic and elemental compositions of TOC corroborate the biomarker results, showing δ13C values and C/N values indicative of aquatic microbial origin. This richness of organic matter and in situ microbial biosignatures differ from previously studied Cl‐dominated Mars‐analog sites which have shown limited OM production and preservation and acidic SO4‐rich hypersaline environments which were dominated by terrestrial inputs. Overall, our results suggest that MgSO4‐rich hypersaline environments are conducive for life and harbor a rich microbial biomarker landscape.

Corrosion Behaviour of Fe-Based and Ni-Based Alloys in Wet CO2 Gas with and without Chloride Deposits at 750 °C

Corrosion behaviours of Fe–25Cr, Fe–25Cr–2Mn–1Si, Fe–25Cr–20Ni, 310SS, Ni–25Cr, and Ni–25Cr–2Mn–1Si (all in wt%) with and without NaCl–KCl deposits in Ar–60%CO2–20%H2O gas at 750 °C were studied. Without salt deposits, Fe–25Cr performed protectively, while Fe–25Cr–20Ni and Ni–25Cr underwent breakaway oxidation with multilayered scales formed. Adding alloy elements Si + Mn increased the corrosion resistance of all alloys by forming additional Mn-rich oxides and silica. Surface deposits of NaCl–KCl accelerated corrosion, forming porous Fe-rich oxide nodules for Fe–25Cr and thick, porous scales and internal oxidation zones for all other alloys. The protective effect of Si + Mn alloying disappeared in the presence of chlorides. Limited intergranular carbides were observed for all alloys in the gas-only condition. The extent of carburisation increased with the presence of chloride deposits for all Fe-based alloys, but remained unchanged for Ni-based alloys. Corrosion of these alloys at 750 °C is compared with that at 650 °C. The effect of chlorides in volatilising metals at 750 °C is discussed.

A Fully Automatic DEXP Method for Gravity Data and Its Application on a Potash Salt Deposit

We developed an improved depth of extreme point (DEXP) method, characterized as an effective and rapid imaging method that can estimate the depth and distribution of a source quickly. Its main purpose is to solve various challenges. The automatic calculation aspect of the traditional method is often limited; namely, there is a problem with achieving automatic and reliable processing when the observed surface presents undulating topography, and this problem cannot be ignored. Therefore, we propose the addition of the constant method and the hypothetical observed surface method to achieve improvements in the traditional method. Firstly, we test the improved method on the synthetic models to demonstrate its notable advantage: the achievement of a fully automatic calculation without requiring any other additional information such as structural index (SI) values and threshold values. Meanwhile, we also demonstrate its ability and reliability to handle undulating topography with acceptable accuracy for imaging results. Furthermore, we verify the robustness of the improved method by applying it to real gravity data from the potash salt deposit in the Sakhon Nakhon basin, Laos. In this case, the improved DEXP method effectively identified the location of the potash deposit. Moreover, combined with the optimal edge detection method, gravity prospecting for potash salt deposits exhibited significant advantages.

Braving the extremes: foraminifera document changes in climate-induced and anthropogenic stress in Wadden Sea salt marshes

Tidal wetlands are highly dynamic ecosystems that are susceptible to changes in sea level and flooding from storm surges. Among them, salt marshes play a key role in coastal protection as they contribute to wave attenuation through their regulating ecosystem services, thereby promoting sediment deposition and shoreline stabilization. However, the resilience of salt marshes, particularly those that have been modified and cultivated for centuries, is questionable in the face of accelerated sea-level rise (SLR) and increasing run-up heights of storm surges. In this context, this study aims to investigate the historical foraminiferal records of two sedimentary salt marsh archives from the Wadden Sea area (Dithmarschen and North Frisia, Germany) that have been modified to varying degrees by human management activities over the last century. The foraminiferal records document how physico-chemical traits of salt marshes of the central Wadden Sea have responded to storm tide inundation over the last century, providing information about salt marsh stability and vulnerability. Abnormally grown tests of the salt marsh indicator speciesEntzia macrescensincreased in number between 1950 CE and the late 1980s, indicating the concurrent increase of environmental stress caused by the effects of times of increased salt marsh flooding. These trends can be linked to observations of amplified North Sea storm surges, corroborating that salt marsh ecosystems respond to changing climate conditions. Differences in the number of abnormal foraminifera between the studied salt marshes suggest a particularly high vulnerability of intensively human-modified coastal wetland ecosystems to amplified storm climate conditions.

Characterization and Resource Potential of Li in the Clay Minerals of Mahai Salt Lake in the Qaidam Basin, China

The strategic importance of lithium in global development has become increasingly prominent due to the rapid growth of the new energy automotive industry and the continuous advancements in controllable nuclear fusion technology. Lithium minerals in salt lakes possess advantageous characteristics, such as abundant reserves, environmental sustainability, and economic viability. Furthermore, with ongoing improvements in the lithium extraction process, the availability of lithium minerals in salt lakes is expected to further increase. The Qaidam Basin Salt Lake in China has served as the location for the establishment of numerous lithium carbonate production enterprises, resulting in a lithium carbonate production volume of 7 × 104 t/yr in 2022. How to meet the growing need for lithium resources has become an enterprise focus. Nevertheless, there are large amounts of clay minerals in and around the bottom and periphery of the salt lake in the Qaidam Basin, and whether these minerals are of exploitable value, regardless of the state of the occurrence of lithium resources, remains unexplored. To ascertain the attributes, extent, and distribution of the lithium occurrence within the clayey layer of the Qaidam Basin, as well as to assess its resource potential, a total of 87 drill holes were conducted within a designated area of the Mahai Basin, which is a secondary basin in the Qaidam Basin. The subsequent analysis encompassed the examination of the lithium content within the clay minerals, the mineral composition of the clay, and, ultimately, the evaluation of the resource potential within the region. Compared with Quaternary salt lake deposits, brine deposits in gravel pores, and the Paleogene–Neogene Li-bearing salt deposits that have been studied, it is suggested that this is a novel form of a clay-type sedimentary Li deposit within the Qaidam Basin. The findings of this research will serve as a fundamental basis for future endeavors pertaining to the exploration and exploitation of lithium deposits within salt lake areas.

Developing a phenomenological model to simulate single and mixed scale formation during flow in porous media: Coupling a salt precipitation model with an ion transport equation under dynamic conditions

Water flooding and pressure maintenance are recommended to improve oil recovery practices after low recovery of petroleum reservoirs occurs during primary production. Salt crystal formation is a frequent occurrence when using these techniques. Several experimental, numerical, and theoretical studies have been done on the mechanisms underlying scaling and permeability reduction in porous media; however, there has not been a satisfactory model developed. This study developed a phenomenological model to predict formation damage caused by salt deposition. Compared with existing models, which provide a scaling tendency, the proposed model predicts the profile of scale deposition. The salt precipitation model simulates reactive fluid flow through porous media. A thermodynamic, kinetic, and flow hydrodynamic model was developed and coupled with the ion transport equation to describe the movement of ions. Further, a set of carefully designed dynamic experiments were conducted and the data were compared with the model predictions. Model forecasts and experimental data were observed to have an average absolute error (AAE) ranging from 0.68% to 5.94%, which indicates the model's suitability.

Morph-genetic biomimetic multiscale porous hydrogels for high-efficient solar evaporation from seawater

Huge seawater resources are of utmost importance in addressing the increasing and severe water shortage worldwide. However, high-efficiently and sustainably extracting fresh water from seawater through solar evaporation remains a challenging task. Herein, we propose a novel approach based on the morph-genetic biomimetic concept, utilizing a cuttlebone-templated directional porous hydrogel (CTDPH). By etching away the cuttlebone (CaCO3) in the hydrogel network, we have developed a zwitterionic material that exhibits high-efficiency photo-thermal conversion, resistance to salt deposition, and super hydrophilicity, enabling high-efficiency solar evaporation. The resultant CTDPH demonstrates a high level of photo-thermal conversion efficiency, thanks to the incorporation of MXene (Ti3C2Tx) 2D nanosheets. By introducing polyzwitterions into the hydrogel matrix, the CTDPH achieves superhydrophilicity, greatly enhancing the transport of seawater. More importantly, the CTDPH possesses a penetrating oriented macro-porous structure, enabling rapid seawater transportation while effectively preventing salt crystallization. This prevents salt deposition on the surface of the hydrogel even during continuous 12-hour 1.0 sun irradiation. As a result, compared with the MXene-free gels and cuttlebone-reserved gels, this CTDPH can largely increase the seawater evaporating rate from 0.73 or 1.75 to 3.11 kg m-2h−1 under 1.0 sun irradiation. Furthermore, even after undergoing 10 cycles of seawater evaporation, the CTDPH still maintains 91.6% of its original solar evaporation rate (2.85 kg m-2h−1). The CTDPH emerges as a promising contender, offering both high efficiency and sustainability for solar evaporation from seawater, while simultaneously paving the way for innovative approaches to explore other materials and systems in the realm of solar evaporation.

THE INFLUENCE OF SALT DEPOSITS ON THE PRESERVATION OF THE HISTORICAL AND ARCHITECTURAL MONUMENT OF THE MAUSOLEUM OF KHOJA AHMED YASAWI

The article presents the results of environmental monitoring of the state of the mausoleum of Khoja Ahmed Yasavi, which is a monument of architecture and history. Mechanisms of processes of formation and development of salt deposits on its building structures are considered. The prospective application of the sorption method for the elimination and inhibition of corrosive salt destruction processes of monuments is shown based on the superimposition of compressing with the complexing agent Trilon B (disodium salt of ethylenediaminetetraacetic acid).

RHEOLOGICAL PARAMETERS OPTIMIZATION OF HYDROCARBON-BASED DRILLING FLUID DEPENDING ON THE MINING AND GEOLOGICAL CONDITIONS OF THEIR APPLICATION

Hydrocarbon-based solutions (HCBS) today are capable ofperforming tasks that water-based muds cannot do. First of all — theability to keep the well walls at a lower density, their insensitivity to clayand salt deposits, the similar nature of the hydrocarbon base and reservoirfluids. These advantages make it possible to use HCBS in the constructionof wells characterized by intensive caving, with high zenithangles and extended horizontal sections. HCBS is successfully appliedat the fields located beyond the Arctic Circle when opening, for example,Devonian deposits. But in addition to the indisputable positive aspects,HCBS also have disadvantages. Among their main disadvantages, highcost is distinguished, which increases the requirements for the quality ofthe solution for trouble-free and fast well drilling, the impossibility ofusing HCBS in absorbing horizons. In addition to the high cost, hydrocarbon-based fluids, due to their nature, are characterized by compressibilityand a non-linear dependence of viscosity on temperature. Simplyput, under the influence of high temperatures, the rheological parametersof the solution decrease, and under the influence of low temperatures,they increase. And if solutions are constantly being found for the firstproblem, improving and developing new viscosity modifiers, emulsifiersand additives, then the second problem has long gone unnoticed. But forthe deposits of the Arctic, characterized by vast zones of permafrost, thesolution of this problem is more relevant than ever. An increase in plasticviscosity when the solution is cooled (for example, in permafrost zones)is possible during long-term circulation stops: during tripping operationsor running casing, etc. This increase in rheology can cause circulationloss, fluid loss, increased timewell construction, and hydraulic fracturing.In this work, we decided to investigate the dependence of the HCBSrheology on temperature and to choose the concentration of reagents thatwill allow leveling this dependence, since, due to the nature of theHCBS, it is impossible to eliminate it completely.

Efforts To Sustain Fresh Water Production in Order to Improve The Performance of Fresh Water Generator On The Mt. Rubra

Fresh water generator is an auxiliary aircraft aboard a ship that produces fresh water by evaporating seawater in the evaporator and the seawater is cooled by condensation in a distillation vessel or condenser (condenser), thus producing condensed water called condensate. Fresh water generator running optimally is one of the important factors to support ship operations, especially the results of the fresh water generator used for cooling systems and daily needs on board. This study aims to find out the causes of the problems and efforts that occur in the fresh water generator so that it can maintain fresh water production results in the fresh water generator. While data analysis is to identify the data set that has been obtained, so that the data can be analyzed and the purpose is analyzed in order to get a clearer picture in the preparation of this research both from the problems and the final results. It is hoped that this research research can produce ideas, solutions and appropriate problem solving, both in observing and dealing with the problems raised in this study. Based on research on fresh water production on fresh water generators in MT. Rubra has decreased from 19 tonnes/day to 12 tonnes/day. This is caused by the occurrence of salt deposits on the evaporator plate so that evaporation becomes late and the low pressure of sea water leading to the fresh water generator causes fresh water production to decrease

Effect of hybridization on mechanical and water absorption properties of short palmyra palm leaf stalk/carbon fibers reinforced polyester composites

AbstractRecently, there has been interest in the development of hybrid composites for diverse industrial applications. In this aspect, this paper explores the mechanical (tensile, flexural, impact, and dynamic mechanical analysis) and water (distilled and seawater) absorption properties of palmyra palm leaf stalk/carbon fiber‐based composites. Hybrid composites with various reinforcement weight ratios were manufactured for the experiment employing the compression molding procedure. To analyze the hybridization effect, composites with a single reinforcement were also produced and evaluated. The results demonstrated that adding carbon fiber to palmyra fiber in the matrix enhances the composites' overall mechanical properties. Field emission scanning electron microscope (FESEM) was used to assess the broken surface of mechanically tested composites to better comprehend the failure causes. The findings of the moisture absorption test have shown that using carbon fiber in composites reduces moisture absorption due to their hydrophobic behavior. In addition, the specimens dipped in seawater absorbed more water due to the higher pH value of seawater and gained more weight due to salt deposition. The results of this study indicate that the hybrid composite formulation P25C75 exhibits a balance between its mechanical properties and environmental resilience, making it a possible lightweight material for structural applications.Highlights Various properties of palmyra palm/carbon hybrid composites were investigated. Addition of carbon fibers to palmyra palm composites enhanced their properties. Hybrid composites exhibit better‐damping property. Performance, environmental effect, and cost are balanced in hybrid composites.

Experimental and Theoretical Study of the Influence of Saline Soils on Frozen Wall Formation

This paper examines the impact of salinity on the thermophysical properties of soils during artificial freezing. It focuses on analyzing heat and mass transfer in saline soils for constructing a frozen wall around a mineshaft at a potash salt deposit. The presence of salts in the groundwater near the contact point with water-protective strata is common in these deposits. Experimental studies were conducted on clay, chalk, and sand to understand the effect of salinity on the freezing temperature, unfrozen water content, specific heat capacity, and thermal conductivity of wet soil. These findings were used to simulate heat and mass transfer in saline soils using a one-dimensional model. The technique of circumferential averaging was introduced to account for the thermal impact of freeze pipes. The results indicate that higher soil salinity leads to a faster decrease in soil temperature under freezing conditions, although this dependence is weak for clay. This study also revealed that an increase in initial salinity results in a reduction in the thickness of the frozen wall. It was found that, for chalk and sand, there exists a range of initial salinity during which the frozen wall’s thickness is almost independent of the initial salinity.

Hydrogel fiber fabric combining rapid water transport, thermal localization, and large-scale production for ultra-high salt-resistant solar desalination

Solar vapor generation (SVG) is one of the most promising strategies for addressing the freshwater shortage crisis. However, fewer existing solar evaporators combine excellent evaporation rates, salt resistance, and large-scale production potential, which are the keys to realizing industrialization. Herein, we prepare sodium alginate/reduced graphene oxide (SA/rGO) hydrogel fibers with complex nano-network structures and introduce a novel compact hydrogel fiber fabric (HFF-C) evaporator by integrating the advantages of hydrogel and fabric for the first time. The HFF-C evaporator exhibits a synergistic impact based on its porous structure and capillary effect between the fibers, along with efficient thermal management, resulting in both efficient water transport and thermal localization. The constructed HFF-C evaporator demonstrates an exceptional evaporation rate (4.13 kg m−2 h−1) in 20 wt% brine under one sun illumination, which is the highest reported value to our knowledge. Importantly, no salt deposition occurs on the evaporator’s surface over 8 h of operation. Furthermore, we successfully prepare an HFF-C evaporator with a large size of 13 × 100 cm2 using a multibeam loom. This study presents a novel design concept for a solar hydrogel-based evaporator with excellent evaporation rates, ultra-high salt resistance, and large-scale production potential, thus promising significant advancements in the practical application of SVG.

Compatible Solutes Accumulated by <i>Glutamicibacter</i> sp. Strain SMB32 in Response to Abiotic Environmental Factors

Abstract—Proton magnetic resonance spectroscopy was used for investigation of the pool of compatible solutes accumulated in the cells of Glutamicibacter sp. strain SMB32 in response to abiotic environmental factors. The original habitat of the strain was anthropogenically salinated soil at the Verkhnekamsk deposit of potassium and magnesium salts (Perm krai, Russia). The strain grew within the temperature range from 5 to 35°C. At 5 and 32°C, the intracellular content of trehalose in the cells of Glutamicibacter sp. SMB32 was significantly higher than at 25°C. Glutamicibacter sp. SMB32 was able to grow both in the absence of NaCl and at its concentrations up to 11%. Glutamate predominated in the cells growth without NaCl. At high salinity (8% NaCl), predominant compounds in the studied strain cells were trehalose, proline, glutamine, and glutamate. Increasing salinity of the growth medium resulted in higher levels of intracellular proline. This is the first report of ability of a Glutamicibacter strain to synthesize mannitol; its accumulation was found to depend on the aeration mode. Thus, Glutamicibacter sp. strain SMB32 possesses high metabolic plasticity and is able to adapt to the action of unfavorable physicochemical factors.