Saturated NaCl Research Articles

Surfactant-assisted air flotation: A novel approach for the removal of microplastics from municipal solid waste incineration bottom ash

The potential for the presence of microplastics (MPs) in municipal solid waste incineration bottom ash (MSWI-BA) has not been fully explored. In this study, surfactant-assisted air flotation separation in aqueous media was used to examine the removal of MPs and other pollutants from different particle size fractions of MSWI-BA. The use of 1 mmol L−1 sodium dodecylbenzene sulfonate (SDBS), at a liquid-solid ratio of 60:1, increased by 66 % the quantity of MPs floated from the MSWI-BA 0–0.3 mm fraction, as compared to pure water. The four most common shapes of the floated MPs were pellets, fragments, films and fibers, and the major polymers were polypropylene, polyethylene, polymethyl methacrylate, and polystyrene (approximately 450 μg g−1 BA). The flotation of <10 μm MPs increased by up to 7 % using this method compared to flotation in saturated NaCl solution. Reuse of the flotation solution with the SDBS concentration maintained resulted in reduced MPs removal abundance by 22 % in the fourth use as compared to the first use. MPs removal correlated positively to SDBS concentration and negatively to turbidity. Precipitation from the fourth flotation solution was evaluated using polyacrylamide (PAM) and polyaluminium chloride (PAC) for the purpose of promoting the regeneration and recycling of the flotation solution. This treatment reduced MPs abundance, turbidity, and potential heavy metals in the recycled flotation solution. It is estimated that 3.4 kg of MPs could be removed from each ton of MSWI-BA. The findings of this study contribute to a better understanding of the redistribution of MPs during MSWI-BA pre-use treatment and provides a reference for the practical application of surfactant-assisted air flotation separation.

Two-dimensional acetate-based light lanthanide fluoride nanomaterials: An ultrahigh adsorption capacity and salt-tolerance endowed by surface acetates exchange

To develop an excellent two-dimensional (2D) adsorbent with an ultrahigh adsorption capacity and salt-tolerance is much of importance in actual wastewater treatment. In this work, 2D acetate-based light lanthanide fluoride nanomaterials (F–Ln nanosheets) are identified as high-efficient adsorbents for anionic dye decoloration. F–Ln nanosheets are prepared through a hydrothermal synthetic methodology at room temperature and pressure. Multiple characterizations demonstrate that surface acetates exchange with exogenous anions is the prominent characteristic of these nanosheets. Adsorption experiments infer that adsorption processes obey a pseudo-second-order kinetics model and a Langmuir isotherm model. The maximum Langmuir adsorption capacity for Congo red and Coomassie brilliant blue G-250 is 4334 mg/g and 2827 mg/g, respectively. The mechanism analysis suggests that surface acetates exchange of F–Ln nanosheets is responsible for their ultrahigh adsorption capacity. Besides, F–Ln nanosheets present an ultrahigh salt-tolerance in saturated NaCl or high-concentration Na2SO4, K2CO3 and NaNO3 solution. Computational studies claim that surface acetates exchange with dye anions, which has a higher binding strength than common salts, is the key to induce an ultrahigh salt-tolerance. With an ultrahigh adsorption capacity and salt-tolerance, we believe that F–Ln nanosheets promise an outstanding platform to develop excellent adsorbents for environment remediation.

SiO2 modified superwetting cotton fabric with anti-crude oil fouling, mechanical stability and corrosion resistance

A superwetting SiO2/PDA/CF membrane was simply fabricated by modifying cotton fabric (CF) with SiO2 and polydopamine (PDA), which exhibits superoleophobicity (i.e., an underwater oil contact angle (UOCA) is 159.7°), and was characterized by TG, SEM, EDS and FTIR. The oil/water separation performance, mechanical stability and corrosion resistance of SiO2/PDA/CF were investigated. The results show that the water fluxes are 34000 and 31300 L·m−2·h−1 for “crude oil/water” and “toluene/water”, respectively. And the oil/water separation efficiencies all are more than 99%. Continuous separation of “crude oil/water” and “toluene/water” for 15 and 100 times, the separation efficiencies are more than 98% and 99%, and the fluxes decrease by 2.9% and 19.7%, respectively. The membrane shows ultra-low adhesion towards crude oil. The as-prepared SiO2/PDA/CF maintains underwater superoleophobicity (i.e., UOCA>150°) after ultrasonically treating for 9 h or 240# sandpaper abrasion for 500 cycles or after exposure to harsh conditions of saturated NaCl, 1 M H2SO4, 1 M NaOH, respectively for 31 days. SiO2/PDA/CF, which is low-cost and environmentally friendly, has good oil/water separation performance, anti-oil fouling, low oil adhesion, mechanical stability, and corrosion resistance, exhibiting great potential applications in solving the serious problem of oily industrial wastewater and oil spills in the ocean.

AUTHENTICATION OF RATTUS NORVEGICUS FAT AND OTHER ANIMAL FATS USING GAS CHROMATOGRAPHY-MASS SPECTROMETRY (GC-MS) AND PRINCIPAL COMPONENT ANALYSIS (PCA)

Objective: The objective of this study was to analyze fatty acids using Gas Chromatography-Mass Spectrometry (GC-MS) in combination with chemometric Principal Component Analysis (PCA) for the authentication of Rattus norvegicus fat from other animal fats.&#x0D; Methods: Extraction of fat from raw meat of Rattus norvegicus, beef, chicken, pork, and dogs using the Bligh Dyer method, then derivatized with 0.2 N NaOCH3, precipitation of sodium glycerol was carried out by adding saturated NaCl to obtain methyl esters which were then injected into the GC-MS instrument. The GC-MS data were then processed using chemometric Principal Component Analysis (PCA) to group Rattus norvegicus fat with other animal fats (beef, chicken, pork, and dog).&#x0D; Results: The results of the study revealed that fatty acids in Rattus norvegicus using GC-MS produced eleven types of fatty acids, namely: Lauric acid (1,1%), Myristic acid (1,15%), Palmitic acid (21,12%), Palmitoleic acid (2,06%), Stearic acid (8,23%), Vaccenic acid (2,43%), Oleic acid (26,51%), Linoleic acid (19,19%), Arachidic acid (0,09%), and Eucosatrienoic acid (0,39%). Chemometrics Principal Component Analysis (PCA) of Rattus norvegicus fat allows it to be classified with other animal fats.&#x0D; Conclusion: The Gas Chromatography-Mass Spectrometry (GC-MS) method, in combination with chemometric Principal Component Analysis (PCA), offered effective tools for the authentication of fatty acid of Rattus norvegicus.

Membrane Distillation Crystallizer Applied for Separation of NaCl Solutions Contaminated with Oil.

In the present study, the membrane crystallizer was used to separate a saturated NaCl solution contaminated with an oil emulsion. The crystallizer was connected via a mesh separator with a feed tank in which capillary submerged modules were assembled. The effect of scaling and oil sorption on the wetting of polypropylene (PP) membranes has been investigated during the long-term studies. It has been found that cooling the solution in the crystallizer by 15 K below the feed temperature resulted in intensive NaCl crystallization in the zone below the mesh separator. A result, the salt crystallization on the membrane surface was eliminated. Contamination of saturated brines with oil in the concentration exceeding 100 mg/L caused the oil penetration into the membrane pores. The application of a PP net assembled on the capillary membranes surface reduced the intensity of wetting phenomenon caused by scaling and the oil sorption, which provides a stable membrane module performance during 1300 h test.

The effects of fibers layer assembled on the capillary membranes applied for separation of brines by membrane distillation

The wetting of hydrophobic membranes caused by scaling phenomenon is the main issue that may constraint the successful applications of membrane distillation (MD) and membrane crystallization, especially during implementation of the Zero Liquid Discharge technologies. In this work, the submerged polypropylene modules were applied for separation of saturated NaCl solutions. The idea that membranes wetting can be reduced when the salts crystallize on the macrostructures covering the membrane surface is presented. To verify this idea, the effect of utilization of protective fibers layer assembled on the capillary membranes on the process performance was investigated. The permeate flux decreased 90% when the salt crystals covered membranes, thus the deposit was periodically dissolved. This operation accelerated the pore wetting and as a result the distillate conductivity increased from 5 to 200 μS/cm. On the contrary, the conductivity increased only to 20 μS/cm for membrane covered by fibers layer. In this case the salt crystalized mainly on the fibers surface, thus the salt dissolution did not wet the pores. The SEM studies confirmed that the fibers layer reduced the formation of salt deposits directly on the membrane surface. In the case of nonprotected membrane, a large amount of NaCl crystals were formed inside the membrane pores, which caused a mechanical damage of the membrane matrix. The scaling intensity and membrane wettability were studied during long-term tests, carried out over 2000 h. It has been found that the application of fibers layer allows to maintain the membranes durability despite intensive scaling phenomenon. In this case, it is essential to obtain mixing conditions in the boundary layer that ensure the feed flow inside the fibers layer.

Self-healing of the textile-reinforced concrete: Additives and coatings

Textile reinforced concrete (TRC) is an attractive alternative to the classic steel rebar reinforcement since the textile is stronger, more flexible, and non-corrosive compared to steel. Moreover, the TRC approach promotes the formation of multiple thin cracks pattern upon loading instead of a few wide cracks in rebar reinforcement. We found that the self-healing of these multiple thin cracks was accelerated by modifying the concrete matrix (addition of crystalline additive and alumina nanofibers) and by decorating the carbon-based textile with micro silica particles. Exposing the TRC samples to a saturated NaCl environment (as in coastal constructions) improved the bonding strength between the textile and the matrix, hence increasing the self-healing capability (compared to samples cured in tap water).

Macroplastics and Microplastics in Intertidal Sediment of Vinces and Los Tintos Rivers, Guayas Province, Ecuador

The composition, abundance and distribution of macroplastics (MAPs) and microplastics (MPs) in the Vinces and Los Tintos rivers were determined in three sites (Pueblo Nuevo, Santa Marianita, Los Tintos) from the low basin in the coastal province of Guayas, Ecuador. MAPS were recorded by visual census, covering a total distance of 140 m, and MPs were extracted in the intertidal sediments via density separation using a saturated NaCl solution, and these were counted using a stereomicroscope. A total of 940 plastic items were identified. The predominant debris was plastic with 85.2%, followed by manufactured materials and metals. The Vinces River contained the highest abundance of plastic in the locality of Pueblo Nuevo. The most abundant plastic was MPs. The most common MAPs were plastic bags (23%), food packaging (17%) and foamed plastic (8%). MP size classes quantified between 0.15 and 2.52 mm in intertidal, very fine sandy sediment and decreased in abundance with increasing grain size. The most common MPs were fibres (65.2%) (black (43.8%) and blue (25.8%)), and their distribution has a high correlation with population density and water flow direction: Santa Marianita 5.55 g−1, Pueblo Nuevo 7.39 g−1, Los Tintos 8.17−1. A significant abundance of fibres was identified in Pueblo Nuevo. The plastic spatial distribution revealed major plastic pollution in areas where recreational and tourism activities have been developed. Therefore, we recommend implementing awareness campaigns by educating businesses, residents and tourists on managing solid waste (especially plastic) and wastewater. Our results can serve as a baseline for future plastic monitoring in the area.

Construction of hierarchical and porous cellulosic wood with high mechanical strength towards directional Evaporation-driven electrical generation

Tremendous efforts have been dedicated to harvesting energy from the ubiquitous natural water evaporation process. Inspired by the plant's bioelectric phenomenon during the transport of sap from bottom to top, the hierarchically porous cellulosic wood was engineered as the robust carrier for efficiently capturing and transferring water and moisture by removing lignin and hemicellulose, releasing the microscale pore in the cell wall and nanoscale pores in the middle lamella. A conductive polymer, poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS), was impregnated in the cellulosic wood, which was further lyophilized to increase the specific surface area and improve the charge transport as an evaporation-driven electrical generator (EEG) with high Young’s modulus. This EEG produces a sustained voltage of around 385 mV and current over 11 μA across the porous and conductive cellulosic wood in a saturated NaCl solution. The anisotropic nature of the cellulosic wood leads to a higher output voltage in the growth direction than in the transverse direction. The driving force behind this energy generation is a self-maintained moisture gradient to generate an ion concentration difference between the output electrodes when the system is exposed to water or moisture. Furthermore, the critical factor of energy generation is the coupling between naturally aligned cellulose microfibrils in wood and water molecule. The generated voltage could be increased by elevating the concentration of ions in the aqueous solution and the temperature difference between the output electrodes. These strong and hierarchical cellulosic wood have a significant potential for electric energy collection through water evaporation and waste heat energy.

One-step hydrothermal synthesis of hierarchically structured MoS2 nanorods via reaction intermediates as self-templates for chemoselective hydrogenation

Two-dimensional (2D) materials have unique planar structures and ultrathin thicknesses, but are prone to restacking and agglomerate due to the high surface energy. Building hierarchical structures is one of the effective ways to exploit their inherent properties and unique structural advantages. We unexpectedly found that the introduction of saturated NaCl solution to the hydrothermal synthesis of MoS2 could significantly change its structure, resulting in the hierarchically structured nanosheet-assembled MoS2 nanorods (R-MoS2) with intercalated alkali ions. The formation process and synthesis mechanism of R-MoS2 via NaNH4Mo3O10·H2O reaction intermediate are systematically revealed by morphology and spectroscopy. Benefiting from this interesting hierarchical structure, the catalytic conversion of R-MoS2 for p-chloronitrobenzene hydrogenation is significantly improved. Density functional theory calculation also demonstrates the intercalation of Na in MoS2 can downshift the d-band center of Mo and favors the key final desorption process.

Estimation of Seed Longevity in Onion Seed Lots by a Vigor Test of Radicle Emergence Test in Artificial Ageing Conditions

The study was conducted to test whether a vigor test of a single count of radicle emergence (RE test) would correlate with the storage potential of 10 seed lots of onion (Allium cepa L.) cultivars in artificial storage conditions. The RE test was performed by counting radicle emergence (2 mm) percentage at 80 h after germination was set up at 20 °C. Seed longevity was determined by storage at 75% relative humidity, obtained by saturated NaCl, at 35 °C over 60 days. Twelve seed samples were taken out during ageing, and seed survival curves were constructed based on normal germination percentages conducted at 20 °C for 12 days in the dark. The seed longevity criterion was P50 (time for the viability to fall to 50%), which was determined through probit analysis by using survival curves. Correlation analysis showed that RE counts at 80 h during germination were highly correlated (p &lt; 0.001) with initial seed quality, Ki (R2 = 0.888) and the half-viability period, P50 (R2 = 0.823). Non-aged pre-storage final normal germination percentages of seed lots were also significantly related to longevity (Ki, R2 = 0.808, p &lt; 0.001, P50, R2 = 0.750, p &lt;0.01), while the level of significance was lower. It can be concluded that the RE test can be used as a fast vigor test to estimate the longevity in onion seed lots.

A multi-omics framework reveals strawberry flavor genes and their regulatory elements.

Flavor is essential to consumer preference of foods and is an increasing focus of plant breeding programs. In fruit crops, identifying genes underlying volatile organic compounds has great promise to accelerate flavor improvement, but polyploidy and heterozygosity in many species have slowed progress. Here we use octoploid cultivated strawberry to demonstrate how genomic heterozygosity, transcriptomic intricacy and fruit metabolomic diversity can be treated as strengths and leveraged to uncover fruit flavor genes and their regulatory elements. Multi-omics datasets were generated including an expression quantitative trait loci map with 196 diverse breeding lines, haplotype-phased genomes of a highly-flavored breeding selection, a genome-wide structural variant map using five haplotypes, and volatile genome-wide association study (GWAS) with &gt; 300 individuals. Overlaying regulatory elements, structural variants and GWAS-linked allele-specific expression of numerous genes to variation in volatile compounds important to flavor. In one example, the functional role of anthranilate synthase alpha subunit 1 in methyl anthranilate biosynthesis was supported via fruit transient gene expression assays. These results demonstrate a framework for flavor gene discovery in fruit crops and a pathway to molecular breeding of cultivars with complex and desirable flavor.

Plastic debris in plastic-mulched soil-a screening study from western Germany.

BackgroundAgricultural plastic mulches offer great benefits such as higher yields and lower pesticide use. Yet, plastic mulches may disintegrate over time and fragment into smaller debris. Such plastic debris is expected to remain in the field after removal of the plastic mulch and thus contributes to soil contamination with plastics.MethodTo investigate this, we collected soil samples at 0–10 cm and 10–40 cm depth from three fields covered with black mulch film for three consecutive years. Three fields without any reported plastic use served as control. Visual plastic debris > 1 cm (macroplastics) was collected from the soil surface. Mesoplastics between 2 mm and 1 cm were density separated from the sampled soil using saturated NaCl solution and analyzed by Fourier-transform infrared spectroscopy. Debris ≤ 2 mm (microplastics) was dispersed from 50 g soil using sodium hexametaphosphate solution followed by the aforementioned density separation. The separated polyethylene (PE), polypropylene (PP), and polystyrene (PS) were quantified via solvent-based pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS).ResultsWith 89–206 fragments ha−1, the majority of macroplastics were located in fields previously covered with mulch films. 80% of the collected specimen were identified as black PE film. The number of mesoplastics in plastic-mulched soil was 2.3 particles kg−1, while only 1.0 particles kg−1 were found in the reference fields. Py–GC/MS revealed microplastic levels of up to 13 mg kg−1. The PE content was significantly higher in plastic-mulched fields than in reference fields.DiscussionAlthough the identified plastic levels are lower than those reported in comparable studies, our results still suggest that plastic mulching functions as a source of plastic debris in agricultural systems. Due to its severely restricted degradability, these plastics are likely to accumulate in soil in the long term and further fragment into smaller and smaller debris.

Salt template tuning morphology and porosity of biomass-derived N-doped porous carbon with high redox-activation for efficient energy storage

In this work, N-doped porous carbon with effective Faraday reaction activation is fabricated by pyrolysis of egg white in air at high temperature using a mixed KCl and NaCl salt sealing strategy. The mechanism of the morphology and pores affecting the redox reaction are discussed in depth and the morphology and porosity of the carbon product are regulated by adding different amounts of saturated NaCl salt solution to egg white before cooking in a water bath. The increasing amounts of saturated NaCl salt solution added to egg white can enable more salt particles to penetrate into carbon framework at high temperature due to the interaction between water molecules and salt particles, leading to the achievement of N-doped porous carbon with thin sheet and mesopore structure. The sheets and mesopores can accelerate the reaction kinetics involved with fast Faraday reaction and diffusion-controlled process by providing more electron and ion transfer expressways, producing the effective Faraday effects of carbon electrodes. Therefore, explored the supercapacitor applications, as-synthesized N-doped porous carbon is exhibited a superb three-electrode specific capacitance of 304 F g−1 at 1 A g −1. The symmetrical surpercapacitors are also displayed a high specific capacitance of 248 F g−1 at 1 A g −1 and a good cycling stability with 98.7% of initial capacitance retention rate undergoing 15 000 cycles at 2.5 A g−1. This work has fundamental merits for the use of the sustainable abandoned eggs and concentrated protein solution feedstocks to prepare carbon electrode materials and further expands the application field of the salt sealing technique.

Initial survey on microplastic waste in coastal water in Nam Dinh

Plastic materials are defined as including the whole of organic polymers owning plasticity. Their production increases rapidly due to their superior properties and applications in our life. Currently, the annual production of plastic is estimated at nearly 400 million tons. About 10% of the plastic produced is discharged into the seas and oceans. Microplastics (MP, less than 5 mm in size) are non-biodegradable and persistent in the environment and have the ability to accumulate in various environmental components, organisms and other human beings through the food chain. Therefore, assessing microplastic pollution becomes essential for the marine and ocean environment. This study aims to evaluate microplastic pollution in Nam Dinh seawater. Water samples were taken in summer 2020 and spring 2021 in Giao Thuy district, Nam Dinh province. Samples were treated with 30% H2O2 solution to remove organic matters and then microplastic buoyantly separated using saturated NaCl solution. MP was identified through observation under a stereo microscope (Olympus SZX2-TR300) and its nature was determined through infrared spectroscopy (µFTIR). Results show that a large level of pollution (average 6 to 8 particles/m3 and 10–14 million particles/km2) is associated with the predominant of colored fibers among MP characteristics. Most of the microplastics identified are Polypropylene in nature. Next, more research needs to be invested in this pollution problem, such as expanding the scope and research object.

Microplastic Extraction from Agricultural Soils Using Canola Oil and Unsaturated Sodium Chloride Solution and Evaluation by Incineration Method

Environmental pollution by microplastics (MPs) has become a global problem, but little is known about MPs in soils. This is because MP extraction methods from soils have not yet been standardized. In this study, we tried to establish a simple and economical method to extract soil MPs using the buoyancy of canola oil and the density separation process using sodium chloride (NaCl). In addition, the incineration method was adapted to evaluate the effectiveness of extraction methods precisely. First, the ability and suitability of seven different oils to extract MP from soil were investigated and canola oil was selected. Then, the spiking and recovery test was performed with canola oil and NaCl solution for low-density polyethylene (LDPE), polypropylene (PP), and polyvinylchloride (PVC) as follows: (1) soil and MP mixtures were prepared, (2) 5 g L−1 NaCl and canola oil were added and shaken thoroughly, (3) the oil phase containing MPs were separated after sedimentation, (4) the extracted MPs were rinsed with 99.5% ethanol, and (5) the organic adherents to the extracted MPs were digested with hydrogen peroxide. After drying and incineration, the substantial recovery rates were calculated. In the spiking and recovery test for MP particles (&lt;1 mm) from five typical Japanese agricultural soils, the recoveries of LDPE, PP, and PVC were 95.2–98.3%, 95.2–98.7%, and 76.0–80.5%, respectively, higher than those obtained by the density separation using saturated NaCl solution. In conclusion, the method is effective for extracting MPs, especially LDPE and PP, from soils and is less sensitive to soil type, texture, and physicochemical properties.

Nanoporous Vesicular Membranes of Amphiphilic Polymers Containing Trans / Cis Isomers

Nanoporous Vesicular Membranes of Amphiphilic Polymers Containing <i>Trans</i> / <i>Cis</i> Isomers

The influence of inorganic salt on coal-water wetting angle and its mechanism on eliminating water blocking effect

Hydraulic stimulation techniques are widely used to improve the CBM production. However, the water blocking effect severely restricts the stimulation effect. In this work, the different kinds of inorganic salts were used to increase the liquid surface tension so that the water blocking effect can be diluted by reversing the capillary force direction. Moreover, the FTIR, XRD, Low-temperature N2 adsorption and coal surface 3D morphology experiments were carried out to analyse the influence of coal surface structure on the wettability. Results showed that the inorganic salts significantly improve the liquid surface tension and coal-water contact angle, can even change the direction of capillary force because the inorganic salt ions are able to combine water molecules and thus lead to a higher mutual attraction of water. The NaCl and CaCl2 show the most remarkable effect on changing wettability and reverse the capillary force. The surface tension of saturated NaCl solutions and saturated CaCl2 solutions increased by 13.92% and 15.79%, respectively. The contact angle of DL coal with saturated NaCl solutions and saturated CaCl2 solutions increased by 42.39% and 42.36%. The contact angle of WL coal with saturated NaCl solutions and saturated CaCl2 solutions increased by 23.35% and 22.88%. Based on Laplace's equation, the maximum reduction of capillary force for DL coal and WL coal are 183.01% (CaCl2) and 374.17% (NaCl), respectively. Finally, the influence of surface structure on the coal wettability were analysed. The carboxyl groups, hydroxyl groups and minerals in the coal can promote the wettability of the coal, leading to a higher water blocking effect. Similarly, the smaller pore size of the coal leads to a greater capillary force and thus inhibit gas transport. This work provides a new idea for eliminating the water blocking effect and improving the effectiveness of hydraulic stimulation techniques.

Surviving in the Brine: A Multi-Omics Approach for Understanding the Physiology of the Halophile Fungus Aspergillus sydowii at Saturated NaCl Concentration.

Although various studies have investigated osmoadaptations of halophilic fungi to saline conditions, only few analyzed the fungal mechanisms occurring at saturated NaCl concentrations. Halophilic Aspergillus sydowii is a model organism for the study of molecular adaptations of filamentous fungi to hyperosmolarity. For the first time a multi-omics approach (i.e., transcriptomics and metabolomics) was used to compare A. sydowii at saturated concentration (5.13 M NaCl) to optimal salinity (1 M NaCl). Analysis revealed 1,842 genes differentially expressed of which 704 were overexpressed. Most differentially expressed genes were involved in metabolism and signal transduction. A gene ontology multi-scale network showed that ATP binding constituted the main network node with direct interactions to phosphorelay signal transduction, polysaccharide metabolism, and transferase activity. Free amino acids significantly decreased and amino acid metabolism was reprogrammed at 5.13 M NaCl. mRNA transcriptional analysis revealed upregulation of genes involved in methionine and cysteine biosynthesis at extreme water deprivation by NaCl. No modifications of membrane fatty acid composition occurred. Upregulated genes were involved in high-osmolarity glycerol signal transduction pathways, biosynthesis of β-1,3-glucans, and cross-membrane ion transporters. Downregulated genes were related to the synthesis of chitin, mannose, cell wall proteins, starvation, pheromone synthesis, and cell cycle. Non-coding RNAs represented the 20% of the total transcripts with 7% classified as long non-coding RNAs (lncRNAs). The 42% and 69% of the total lncRNAs and RNAs encoding transcription factors, respectively, were differentially expressed. A network analysis showed that differentially expressed lncRNAs and RNAs coding transcriptional factors were mainly related to the regulation of metabolic processes, protein phosphorylation, protein kinase activity, and plasma membrane composition. Metabolomic analyses revealed more complex and unknown metabolites at saturated NaCl concentration than at optimal salinity. This study is the first attempt to unravel the molecular ecology of an ascomycetous fungus at extreme water deprivation by NaCl (5.13 M). This work also represents a pioneer study to investigate the importance of lncRNAs and transcriptional factors in the transcriptomic response to high NaCl stress in halophilic fungi.

Creating saturated sodium chloride solutions through osmotically assisted reverse osmosis

Increasing sustainability awareness has created opportunities for the recovery and reuse of salt solutions in industrial processes. Osmotically assisted reverse osmosis (OARO) has the potential to concentrate these salt solutions. Until now OARO research focussed on the production of purified water yielding an unsaturated salt solution as retentate, whereas a saturated salt solution is often needed for reuse. OARO featuring recycling of part of the saturated salt solution to the permeate side of the membrane has now been investigated. The introduction of a saturated NaCl solution results in strongly changing osmotic pressure difference and flux profiles along the length of the modules, with a maximum osmotic pressure difference and a minimum flux close to the outlet of the OARO system. In contrast to the NaCl retention of the membrane, the NaCl feed concentration does not have an influence on the maximum osmotic pressure difference. The osmotic pressure difference and membrane flux are strongly dependent on the applied concentrate split factor, which has a strong effect on the required membrane area per feed flow supplied as well. The amount of surface area required per flow of saturated NaCl solution leaving the OARO unit has an optimum as function of the concentrate split factor. This is due to two counteracting effects, the lower osmotic pressure difference, and the lower fraction of saturated NaCl solution leaving the OARO for a higher concentrate split factor. Based on the modelling, essential knowledge has been generated for the further research and development of OARO.