High Concentrations Of Sodium Chloride Research Articles

Engineering an upconversion fluorescence sensing platform with "off-on" pattern through specific DNAzyme-mediated signal amplification for supersensitive detection of uranyl ion.

Anupconversion fluorescence sensing platform was developedwith upconversion nanoparticles (UCNPs) as energy donors and gold nanoparticles (AuNPs) as energy acceptors, based on the FRET principle. They were used for quantitativedetection ofuranyl ions (UO22+) by amplifying the signal of the hybrid chain reaction (HCR). When UO22+ are introduced, the FRET between AuNPs and UCNPs can be modulated through a HCR in the presence of high concentrations of sodium chloride. This platform providesexceptional sensitivity, with a detection limit as low as 68pM for UO22+ recognition. We have successfully validated the reliability of this method by analyzing authentic water samples, achieving satisfactory recoveries (89.00%-112.50%) that are comparable to those of ICP-MS. These results indicate that the developed sensing platform has the capability to identify trace UO22+ in complex environmentalsamples.

Screening and identification of salt tolerance soybean varieties and germplasms

Soil salinization is a globally prevalent abiotic environmental stress. The imbalance of ions caused by high concentrations of sodium chloride results in a 40% reduction in soybean yield. Soybean, as an important crop for soil quality improvement, necessitates the identification of salt-tolerant varieties and germplasms to effectively utilize and enhance saline-alkali land. In this study, we assessed the salt tolerance of 435 soybean varieties and germplasms during the seedling stage. Among them, Qihuang34, You2104, Hongzhudou, Pamanheidou, and Osage exhibited grade 1 salt tolerance rates surpassing other tested materials. Furthermore, Hongzhudou and Qihuang34 demonstrated higher salt tolerance during germination and emergence stages based on their elevated rates of emergence, salt tolerance index, chlorophyll content, and shoot fresh weights. Overall findings provide valuable resources for molecular breeding efforts aimed at developing salt-tolerant soybean varieties suitable for cultivation in saline-alkali soils.

Evaluation of microwave irradiated Polyacrylamide grafted Opuntia leaf mucilage graft copolymer (OPM-g-PAM) as effective controlled release polymer for release of Rosuvastastin as model drug

Controlled drug delivery systems offer numerous advantages. This research evaluates Opuntia leaf mucilage grafted with polyacrylamide (OPM-g-PAM) as a promising controlled-release polymer. PAM chains were grafted onto the backbone of OPM using a microwave-assisted method. Optimization of the best grade was based on % grafting efficiency and intrinsic viscosity, followed by extensive physical and analytical characterizations. Analytical characterizations revealed semicrystalline nature of the biomaterial. SEM and AFM observations revealed rough and porous surfaces, indicating effective grafting. Swelling behavior showed maximum sensitivity at pH 7, with reduced swelling at higher sodium chloride concentrations. A comparative study of % drug release of Rosuvastatin over 24 h showed that the optimized grade controlled drug release effectively, achieving 78.5 % release compared to 98.8 % for GF-3. The release data fitted the Korsmeyer-Peppas model, with an “n” value of 0.8334, indicating non-Fickian (anomalous) diffusion. Bacterial biodegradability studies confirmed the high biodegradability of the graft copolymer. In vitro acute toxicity tests showed no toxicity, as confirmed by histopathological studies of heart, liver, and kidney. Overall, the results indicate that OPM-g-PAM is a highly promising material for use in drug delivery systems, demonstrating potential as a novel controlled-release polymer.

Wood Distillate Promotes the Tolerance of Lettuce in Extreme Salt Stress Conditions.

Soil salinization is an adverse phenomenon in agriculture that severely affects crop growth and yield. The use of natural products, such as wood distillate (WD, derived from the pyrolysis of woody biomass), could be a sustainable approach to enhance the tolerance of plants cultivated in the saline soils. Hence, this study aimed to evaluate the potential of WD, a foliar sprayed at 0.2% (v/v), in lettuce plants subjected to grow under both moderate and high soil sodium chloride (NaCl) concentrations (ranging from 0 to 300 mM). The changes in the physiological and biochemical responses of these plants to the varying salt stress conditions allowed the identification of a maximum tolerance threshold (100 mM NaCl), specific to lettuce. Beyond this threshold, levels related to plant defense antioxidant power (antiradical activity) were lowered, while those indicative of oxidative stress (malondialdehyde content and electrolyte leakage) were raised, causing significant losses in leaf fresh biomass. On the other hand, WD significantly improved plant growth, enabling plants to survive high salt conditions >200 mM NaCl. Collectively, these observations highlight that treatments with WD could be of paramount importance in coping with current environmental challenges to have better yields under soil conditions of high salt concentrations.

Assessment of the phenotypic and genotypic diversity of endophytic strains of Bacillus and closely related genera from Carpinus betulus in the Hyrcanian forests of Iran.

Identification and characterization of the endophytic microorganism, is gaining their underestimated significance in influencing health, performance, and other biological attributions of plants in general and forest tree species in particular. Because of the scarcity of information on the endophytic microbiome of the Hyrcanian forests species, including hornbeam (Carpinus betulus L.) trees, as a major constituent thereof, the present study aimed at the identification and partial characterization of the endophytic Bacillus species of Carpinus betulus as the first step in this context. Shoot samples were collected from the Hyrcanian forest locations of Mazandaran and Golestan provinces in Iran. Bacterial strains were isolated from the surface-disinfected shoot segments and subjected to phenotypic characterization. Following assessment of the genetic diversity of the isolates by BOX-PCR fingerprinting, the representative isolates of each of the 15 groups were used for further characterization. Analysis of the nucleotide sequences of the 16S rDNA and HSP60 gene of the isolates led to the identification of 10 species. The predominant species was B. cereus followed by B. subtilis. The other species encountered were B. thuringiensis, Priestia filamentosa, B. velezensis, B. mojavensis, B. amyloliquefaciens, B. safensis, P. aryabhattai, and Gottfriedia acidiceleris. Most isolates possessed characteristics which could contribute to the biocontrol potential of the isolates, including formation of biofilm, production of hydrogen cyanide, tolerant to relatively high concentration of sodium chloride, and antibacterial activity. Ten Bacillus species were identified as the prevailing endophytic species of C. betulus in the Hyrcanian forest of northern Iran, most turned up to possess biological activities involved in biocontrol capability of the isolates against some plant pathogens. These potentially capable bacteria could be implemented in the promotion of plant growth as well as in the biological control of pathogens. This is the first report on the characterization and elucidation of the diversity of the potentially beneficial endophytic species of Bacillus and the closely related genera living in the internal tissues of hornbeam trees.

SarCTAB: an efficient and cost-effective DNA isolation protocol from geophytes.

Geophytes are herbaceous plants that grow anew from underground buds and are excellent models to study storage organ formation. However, molecular studies involving geophytes are constrained due to the presence of a wide spectrum of polysaccharides and polyphenols that contaminate the genomic DNA. At present, several protocols exist for the extraction of genomic DNA from different plant species; however, isolating high-quality DNA from geophytes is challenging. Such challenges are further complexed by longer incubation time and multiple precipitation steps involved in existing DNA isolation methods. To overcome such problems, we aimed to establish a DNA extraction method (SarCTAB) which is an economical, quick, and sustainable way of DNA isolation from geophytes. We improved the traditional CTAB method by optimizing key ingredients such as sarcosine, β-mercaptoethanol, and high molar concentration of sodium chloride (NaCl), which resulted in high concentration and good-quality DNA with lesser polysaccharides, proteins, and polyphenols. This method was evaluated to extract DNA from storage organs of six different geophytes. The SarCTAB method provides an average yield of 1755ng/µl of high-quality DNA from 100mg of underground storage tissues with an average standard purity of 1.86 (260/280) and 1.42 (260/230). The isolated genomic DNA performed well with Inter-simple sequence repeat (ISSR) amplification, restriction digestion with EcoRI, and PCR amplification of plant barcode genes viz. matK and rbcL. Also, the cost involved in DNA isolation was low when compared to that with commercially available kits. Overall, SarCTAB method works effectively to isolate high-quality genomic DNA in a cost-effective manner from the underground storage tissues of geophytes, and can be applied for next-generation sequencing, DNA barcoding, and whole genome bisulfite sequencing.

Metods for creating salt – tolerant long – grin varieties in Karakalpakstan

The article presents the results of breeding methods for creating salt-tolerant long – grain rice varieties. For this purpose, collection samples and the best varieties of rice from different ecological and geographical zones were studied according to agrobiological characteristics in comparison with the zoned ultra-early ripening long – grain varieties “Sanam”. After a comprehensive study and comprehensive assessment in the field conditions, ultra-early ripening long-grain forms with positive traits and properties were identified. These selected varieties were assessed far salt tolerance in laboratory conditions during the seed germination phase in an artificially created 1.5% solution (NaCl) of sodium chloride. A high concentration of sodium chloride has an adverse effect on germination rates and seedling size. At high concentrations of saline solution, these indicators sharply decrease in all studied varieties. However, such a decrease, depending on the genotypic characteristics of the variety samples, does not occur to the same extent. Under saline conditions, the characteristic differences between the characteristic of the seedling and the root system changes greatly. The growth and formation of roots was particularly inhibited compared aboveground part of the seedlings. Changes in the performance of the root system in a saline environment for the better can be considered adaptive properties to stressful salinity conditions. Based on the study of germination and seedling parameters, the most salt-tolerant varieties were identified, including Almaz; D-42 (D-11) 35-05-2); D-134 (D-34) (D-143); D-61 (K-316) Viktoriya). These varieties successfully overcome the adverse effects of high concentrations, of sodium chloride solution.

Differential gene expression patterns and physiological responses improve adaptation to high salinity concentration in pepper accessions.

High salinity decreases the productivity of crops worldwide. Pepper is particularly sensitive to high salt concentrations. Herein, we subjected three tolerant pepper accessions (C12, B14 and A25) to high sodium chloride concentration (70 mM NaCl). The aerial and root biomass, leaf and root osmotic potential (Ψπ ), Na+ , Cl- , K+ and proline concentrations and the relative expression of the putative genes CaSOS1, CaHKT1, three CaNHXs and CaP5CS were measured. Different salinity tolerance strategies depending on the pepper accession were identified. In C12, tolerance was attributed to the accumulation of Na+ in vacuoles and endosomes by the activation of vacuolar CaNHXs genes and the reduction in Ψπ ; additionally, the activation of CaHKT1 and CaSOS1 in leaves and roots moved and accumulated Na+ ions in the xylem and xylem parenchyma cells (XPC) as well as expulsed it out of the root cells. A25 accession, on the contrary, was specialized in compartmentalizing Na+ ions in root and leaf vacuoles and root XPC by the up-regulation of CaNHXs and CaHKT1, respectively, avoiding a toxic accumulation in leaves. Finally, B14 accession moved and accumulated Na+ in xylem and XPC, reducing its concentration in roots by the activation of CaSOS1 and CaHKT1. This study shade light on different tolerance mechanisms of pepper plants to overcome salt stress.

High-cell-density cultivation of Vibrio natriegens in a low-chloride chemically defined medium

Vibrio natriegens is a halophilic bacterium with the fastest generation time of non-pathogenic bacteria reported so far. It therefore has high potential as a production strain for biotechnological production processes or other applications in biotechnology. Culture media for V. natriegens typically contain high sodium chloride concentrations. The corresponding high chloride concentrations can lead to corrosion processes on metal surfaces in bioreactors. Here we report the development of a low-chloride chemically defined medium for V. natriegens. Sodium chloride was completely replaced by the sodium salts disodium hydrogen phosphate, disodium sulfate, and sodium citrate, while keeping the total concentration of sodium ions constant. The use of citrate prevents the occurrence of precipitates, especially of ammonium magnesium phosphate. With this defined medium, high-cell-density fed-batch cultivations in laboratory-scale bioreactors using exponential feeding yielded biomass concentrations of more than 60 g L−1.Key pointsA defined medium for V. natriegens that only contains traces of chloride was developedCorrosion processes on metal surfaces in industrial bioreactors can thus be preventedHigh yields of biomass can be achieved in fed-batch cultivation with this medium

Efficacy of BREATHOX® Device Inhalation on Acute Symptoms Associated with COVID-19 (BREATH Study): A Randomized Pilot Clinical Trial.

(1) Background: A high concentration of sodium chloride on in vitro cell culture leads to reduced SARS-CoV-2 replication. Therefore, our aim was to evaluate the effects of inhaling hypertonic NaCl particles (BREATHOX®) on the duration of COVID-19-induced acute symptoms. (2) Methods: A prospective, open label, randomized, standard of care-controlled group (SOC) pilot trial compared inhaled oral and nasal administered BREATHOX® (2.0 mg NaCl, particles size between 1-10 μm), with five or ten inhalations per day for ten days. The primary endpoint was the time to resolve COVID-19-related symptoms. Safety outcomes included adverse clinical and laboratory events. (3) Results: A total of 101 individuals were screened and 98 were randomly assigned to BREATHOX® ten sessions per day (Group 1; 33 patients), BREATHOX® five sessions per day (Group 2; 32 patients), or SOC (33 patients), and followed up for 28 days. There was an association with cough frequency after 10 days BREATHOX® compared to SOC [Group 1: hazard ratio (HR) 2.01, 95% confidence interval (CI) 1.06-3.81; Group 2: HR 2.17, 95% CI 1.17-4.04]. No differences between the groups for the reported symptoms' resolution time were seen after 28 days. After combining both BREATHOX® groups, the period to cough resolution 10 days after randomization was significantly lower than in SOC (HR 2.10, 95% CI 1.20-3.67). An adverse event occurred in 30% of Group 1, 36% of Group 2, and 9% in SOC individuals. One patient from SOC had a serious adverse event. Nasal burning, sore or itchy nose, and dry mouth were considered related to BREATHOX® use and resolved after stopping inhalations. (4) Conclusion: BREATHOX® inhalation is safe and may be effective in reducing the duration of COVID-19-induced coughing.

Germination Ecology of African Lovegrass (Eragrostis curvula) and Herbicide Options for Its Control

African lovegrass (Eragrostis curvula) is one of the invasive perennial grasses that continues to disturb natural ecosystems globally. Experiments were conducted in southeast Queensland, Australia, to evaluate the effects of temperature, salt stress, water stress, burial depth, and sorghum crop residue load on the emergence and efficacy of postemergence herbicides on two populations (Clifton and Crows Nest) of E. curvula. The optimal germination temperature regimes for E. curvula were 30/20 and 35/25 °C, but seeds did not germinate at temperatures commonly occurring in the Queensland winter (15/5 °C). Total darkness inhibited germination by 79%, indicating that the shade cover effect would reduce germination of E. curvula. The Clifton population tolerated a higher concentration of sodium chloride (160 mM) and osmotic potential (−0.8 MPa). Under both salt and water stress, germination was 31% and 20% greater in the Clifton population than in Crows Nest, respectively, suggesting that the Clifton population is more tolerant to salt and drought stress. The maximum germination was obtained for the surface seeds while emergence declined with increased burial depth up to 4 cm. No seedlings emerged from the 8 cm depth. The addition of sorghum residue amounts up to 8 Mg ha−1 to the soil surface inhibited emergence compared to the no-residue treatment, suggesting that retention of heavy cereal residue will further delay or restrict emergence. Several postemergence herbicides were found to be effective in controlling E. curvula at an early stage. Information from this study will further compliment earlier studies on the targeted management of E. curvula populations.

Energy-related wastewater contamination alters microbial communities of sediment, water, and amphibian skin

To inform responsible energy development, it is important to understand the ecological effects of contamination events. Wastewaters, a common byproduct of oil and gas extraction, often contain high concentrations of sodium chloride (NaCl) and heavy metals (e.g., strontium and vanadium). These constituents can negatively affect aquatic organisms, but there is scarce information for how wastewaters influence potentially distinct microbiomes in wetland ecosystems. Additionally, few studies have concomitantly investigated effects of wastewaters on the habitat (water and sediment) and skin microbiomes of amphibians or relationships among these microbial communities. We sampled microbiomes of water, sediment, and skin of four larval amphibian species across a gradient of chloride contamination (0.04–17,500 mg/L Cl) in the Prairie Pothole Region of North America. We detected 3129 genetic phylotypes and 68 % of those phylotypes were shared among the three sample types. The most common shared phylotypes were Proteobacteria, Firmicutes, and Bacteroidetes. Salinity of wastewaters increased dissimilarity within all three microbial communities, but not the diversity or richness of water and skin microbial communities. Strontium was associated with lower diversity and richness of sediment microbial communities, but not those of water or amphibian skin, likely because metal deposition occurs in sediment when wetlands dry. Based on Bray Curtis distance matrices, sediment microbiomes were similar to those of water, but neither had substantial overlap with amphibian microbiomes. Species identity was the strongest predictor of amphibian microbiomes; frog microbiomes were similar but differed from that of the salamander, whose microbiome had the lowest richness and diversity. Understanding how effects of wastewaters on the dissimilarity, richness, and diversity of microbial communities also influence the ecosystem function of communities will be an important next step. However, our study provides novel insight into the characteristics of, and associations among, different wetland microbial communities and effects of wastewaters from energy production.

High extracellular sodium chloride concentrations induce resistance to LPS signal in human dendritic cells.

Recent evidence showed that in response to elevated sodium dietary intakes, many body tissues retain Na+ ions for long periods of time and can reach concentrations up to 200mM. This could modulate the immune system and be responsible for several diseases. However, studies brought contrasted results and the effects of external sodium on human dendritic cell (DC) responses to danger signals remain largely unknown. Considering their central role in triggering T cell response, we tested how NaCl-enriched medium influences human DCs properties. We found that DCs submitted to high extracellular Na+ concentrations up to 200mM remain viable and maintain the expression of specific DC markers, however, their maturation, chemotaxis toward CCL19, production of pro-inflammatory cytokines and ROS in response to LPS were also partially inhibited. In line with these results, the T-cell allostimulatory capacity of DCs was also inhibited. Finally, our data indicate that high NaCl concentrations triggered the phosphorylation of SGK1 and ERK1/2 kinases. These results raised the possibility that the previously reported pro-inflammatory effects of high NaCl concentrations on T cells might be counterbalanced by a downregulation of DC activation.

Exploring Uncharted Marine Bacteria as a Source of Novel Antimicrobials

Marine microbes are defined by their habitat as microorganisms living in the sea or ocean. The term “marine microbes” includes viruses, protozoa and fungi. This microbial life constitutes 70% To 90% of marine biomass. More than 15000 bioactive compounds have been isolated from marine fungi, and other organisms and used as anti-inflammatory, and anticancer leads. Among the microorganisms of marine, bacteria are the least explored ones. Marine actinobacteria have adapted to high hydrostatic pressure, high concentration of Sodium Chloride, low concentration of organic matter, and low temperature. The phylum actinobacteria is a Gram-positive, nonmotile, and aerobic bacteria. Streptomyces and Actinomycetes are studied largely in this phylum due to their ability to produce a wide array of extracellular enzymes and secondary metabolites. Examples of active compounds isolated from Streptomyces include Fijimycins, etamycin A, Chlorinated bisindole pyrroles, and dynamics A–E. There may be diverse extremo enzymes hidden in the shadows that are currently unknown and, if discovered, may open up interesting new methods for the production and use of novel antimicrobials. In pharmaceutical research, a very small fraction of such organisms is studied. If discovered may open up interesting new ingenious, and cost-effective methods for the production and use of many novel anti-microbials.

Surface electrostatics dictate RNA-binding protein CAPRIN1 condensate concentration and hydrodynamic properties

Biomolecular condensates concentrate proteins, nucleic acids, and small molecules and play an essential role in many biological processes. Their formation is tuned by a balance between energetically favorable and unfavorable contacts, with charge-charge interactions playing a central role in some systems. The positively charged intrinsically disordered carboxy-terminal region of the RNA-binding protein CAPRIN1 is one such example, phase separating upon addition of negatively charged ATP or high concentrations of sodium chloride (NaCl). Using solution NMR spectroscopy, we measured residue-specific near-surface electrostatic potentials (ϕENS) of CAPRIN1 along its NaCl-induced phase separation trajectory to compare with those obtained using ATP. In both cases, electrostatic shielding decreases ϕENS values, yet surface potentials of CAPRIN1 in the two condensates can be different, depending on the amount of NaCl or ATP added. Our results establish that even small differences in ϕENS can significantly affect the level of protein enrichment and the mechanical properties of the condensed phase, leading, potentially, to the regulation of biological processes.

Interactions of Candida tropicalis pH-related antigen 1 with complement proteins C3, C3b, factor-H, C4BP and complement evasion

Candida, as a part of the human microbiota, can cause opportunistic infections that are either localised or systemic candidiasis. Emerging resistance to the standard antifungal drugs is associated with increased mortality rate due to invasive Candida infections, particularly in immunocompromised patients. While there are several species of Candida, an increasing number of Candida tropicalis isolates have been recently reported from patients with invasive candidiasis or inflammatory bowel diseases. In order to establish infections, C. tropicalis has to adopt several strategies to escape the host immune attack. Understanding the immune evasion strategies is of great importance as these can be exploited as novel therapeutic targets. C. albicans pH-related antigen 1 (CaPra1), a surface bound and secretory protein, has been found to interact strongly with the immune system and help in complement evasion. However, the role of C. tropicalis Pra1 (CtPra1) and its interaction with the complement is not studied yet. Thus, we characterised how pH-related antigen 1 of C. tropicalis (CtPra1) interacts with some of the key complement proteins of the innate immune system. CtPra1 was recombinantly produced using a Kluyveromyces lactis yeast expression system. Recombinant CtPra1, was found to bind human C3 and C3b, central molecules of the complement pathways that are important components of the innate immune system. It was also found to bind human complement regulatory proteins factor-H and C4b-binding protein (C4BP). CtPra1-factor-H and CtPra1-C4BP interactions were found to be ionic in nature as the binding intensity affected by high sodium chloride concentrations. CtPra1 inhibited functional complement activation with different effects on classical (∼20 %), lectin (∼25 %) and alternative (∼30 %) pathways. qPCR experiments using C. tropicalis clinical isolates (oral, blood and peritoneal fluid) revealed relatively higher levels of expression of CtPra1 gene when compared to the reference strain. Native CtPra1 was found to be expressed both as membrane-bound and secretory forms in the clinical isolates. Thus, C. tropicalis appears to be a master of immune evasion by using Pra1 protein. Further investigation using in-vivo models will help ascertain if these proteins can be novel therapeutic targets.

Use of Slightly Pressurized Carbon Dioxide to Enhance the Antimicrobial Properties of Brines in Naturally Processed Black Table Olives.

Naturally fermented black table olives are processed at low pH in the presence of high sodium chloride concentrations ranging from 8 to 12% (w v−1). Reducing the salt content of brine has become an urgent issue as it is responsible for several health and environmental problems. The study aim was to evaluate slightly pressurized CO2 (spCO2) as a third barrier to microbial growth in naturally processed black table olives with low pH and a reduced NaCl concentration. Based on the assessments performed on a pilot plant scale, an spCO2 of 1 bar completely inhibited the growth of the bacteria and molds in the presence of reduced saline concentrations. Furthermore, the amount of yeast decreased in the brine as a function of the NaCl content. Laboratory tests performed under spCO2 conditions using a single yeast species from the same habitat confirmed the high sensitivity of some oxidizing yeasts and indicated that the fermenting yeast, Saccharomyces cerevisiae, is the most tolerant species. Overall, in the brine of naturally processed olives with a low pH between 4 and 4.2, the antimicrobial properties observed with the high concentrations of NaCl can be achieved with a lower salt dose of 5% (w v−1) when combined with spCO2.

PERFORMANCE OF POLYMER GROUTS MADE FROM WASTES FOR PERMEABLE RIGID PAVEMENT CONNECTIONS

This research developed polymer grouts made from wastes such as fly ash, palm oil fuel ash, and silica fume. The selected polymer grouts served as an interlocking key between the StormPav covers and as a grout to seal the gaps between the interlocking keys and StormPav covers. Based on compressive strength and workability of the polymer grouts, mix ratio of resin to fly ash = 1:1.00 was chosen as the grout, while mix ratio of resin to fly ash = 1:1.50 was used to form an interlocking key. Mix ratios of resin to fly ash = 1:1.00 and resin to fly ash = 1:1.50 had a compressive strength of 98.90 MPa and 81.70 MPa, respectively, and flexural strength of 53.00 MPa and 61.90 MPa. Moreover, increasing the fly ash content in polymer grout decreased the water absorption and volume of permeable voids. In terms of shear strength, the mix ratio of resin to fly ash = 1:1.00 performed well as grout, with a determined shear strength of 3.98 MPa. Even after 25 days of exposure to the high concentration of sodium hydroxide, sulphuric acid, sodium chloride, and magnesium sulphate, the determined shear strength met the minimum shear strength requirement of 1.38 MPa as stated by the Iowa Department of Transportation. Therefore, it can be concluded that both selected mix ratios were suitable for use as grout and interlocking key due to their good physical and mechanical properties.

Simultaneous phosphate recovery and sodium removal from brackish aquaculture effluent via diafiltration-nanofiltration process

Expansion of the aquaculture industry has been accompanied by environmental impact as the discharged effluent contains excess nutrients such as phosphorus compounds. Recovery of such nutrients is not economically feasible as it presents in trace amounts. Furthermore, brackish aquaculture effluent which contains high sodium chloride (NaCl) content makes the treated solution inappropriate for fertilizer production. Herein, this study proposed a diafiltration-nanofiltration route to perform a simultaneous phosphate concentrating and osmotion (sodium) removal from brackish aquaculture effluent. Effects of operating pressure, phosphate, and sodium content on membrane performance were first determined using Desal-5 DK membrane with three types of solutions namely (i) freshwater without NaCl, (ii) dilute brackish water with 1,500 mg/L NaCl, and (iii) brackish water with 10,000 mg/L NaCl. It was found that at 4 bar operating pressure, it could achieve higher phosphate rejection and sodium permeance. The presence of NaCl negatively influenced both phosphate rejection and concentrating factor (CF) due to the salt screening effect. It was noteworthy that negative sodium rejection (up to -16%, CF <1) could be attained, indicating the concentrating effect for sodium was negligible. The concentrating process was effective to concentrate phosphate by 2-fold but less effective in removing sodium. Diafiltration was then introduced and resulted in about 76% of sodium removal. Diafiltration-nanofiltration (DF-NF) mode was shown to be a more efficient method than nanofiltration-diafiltration (NF-DF) mode as phosphate could be concentrated up to 2 factors with 99 wt% of sodium being removed from the real brackish aquaculture effluent. These findings showed that DF-NF is a feasible approach for concentrating phosphate while removing sodium ions from aquaculture effluent and the recovered nutrient solution has huge potential to be applied as liquid fertilizer for hydroponic plants.

Sweet basil can be grown hydroponically at low phosphorus and high sodium chloride concentration: Effect on plant and nutrient solution management

Agronomic inputs in agriculture easily exceed crop needs causing environment pollution. Phosphorus (P) is a macronutrient largely used in agriculture as a mineral fertilizer that requires an accurate management because it is a finite and non-renewable resource. Growing plants hydroponically can optimize plant nutrition achieving high crop nutrient use efficiency. However, irrigation water of poor quality (saline) interferes with crop performance. In this study, the effects of different P and NaCl levels in the root zone were evaluated on basil plants grown in a deep liquid culture system in a growth chamber. Two experiments with different P (from 0.1 to 1.0 mol m−3) and NaCl (from 0 to 60 mol m−3) concentrations in the nutrient solution were carried out. Plant growth, leaf gas exchanges and fluorescence, uptake of minerals and water, and leaf quality (content of minerals and pigments, and antioxidant capacity) were analysed. The most relevant morphological plant response to the low P (i.e., roughly 0.1 x of a standard nutrient solution) concentration consisted in a greater root/shoot ratio. However, plants growing at low P concentration did not show any reduction in yield and quality. Sodium chloride did not significantly affect plants yield and quality up to a concentration of 30 mol m−3 confirming the tolerance of basil to moderate saline stress. Significant reduction in the total biomass, water uptake and photosynthesis instead occurred at NaCl 60 mol m−3. These results confirmed the hypotheses that basil can be grown hydroponically at low P and high NaCl concentration with proper management of the nutrient solution. The absence of significant interactions between P and NaCl suggests that these two factors can be managed independently with potential benefits for crop economic and environmental sustainability.