High Salinity Concentrations Research Articles

Management of groundwater resources in the Tolga region (south-east Algeria)

This study attempted to assess and map the quality of Tolga's groundwater in order to determine its suitability for human consumption and agricultural use. The results of analyses of the physicochemical parameters of the water samples were compared with WHO potability standards and standard agricultural water quality indices, namely sodium adsorption ratio SAR ,Soluble sodium percentage Na% , Magnesium risk MH , Kelly ratio KR and permeability index PI. According to the results analysed, most of the physicochemical parameters are above WHO tolerance limits and within the limits of empirical water quality indices for agricultural use. In our study, the graphical maps obtained by kriging are fitted with theoretical variogram models that best approximate the point cloud. The suitability of these models for our sample is verified by cross-validation results. The graphical representation shows high concentrations of conductivity, salinity, calcium, magnesium, sodium, bicarbonate and chloride, which are located in the Eastern part of the region, and increase progressively from northwest to east. These waters are highly charged with salts and have maximum conductivity values.

Effect of Salt Stress on Botanical Characteristics of Some Table Beet (Beta vulgaris L.) Cultivars.

Salinity inhibits the uptake of nitrogen, which slows down the growth and prevents plant reproduction. Certain ions, especially chloride, are poisonous to plants; when their concentration increases, the plant becomes poisoned and eventually perishes. The adaptability of several table beet cultivars (Beta vulgaris L.) to saline water irrigation creates new opportunities for extending beet production, increases the added economic value, and has a positive environmental impact. A pot experiment is carried out for two successive seasons, 2019/2020 and 2020/2021, to investigate the effect of irrigation with agriculture saline drainage water on the growth and biochemical traits of three selected cultivars (Detroit Dark Red, Red Ball, and Red Ace). Four levels of salinity are applied (1000, 2000, 3000, and 4000 ppm) along with tap water of 260 ppm salinity, which serves as the control. Detroit Dark Red beets show the best results among the other cultivars under consideration. Irrigation with the first level of saline water (1000 ppm) at both seasons of cultivation results in a significant increase rate in growth parameters (13-23%). The second level of salinity (2000 ppm) shows the maximum increase rate of some chemical constituents, such as ascorbic acid (16.26%), nitrogen (58.21%), phosphorus (11.94%), potassium (34.66%), and sodium (85.14%). The levels of total soluble solids (TSS), anthocyanins, proline, total sugars, water saturation deficit, and sodium increase significantly in proportion to saline water concentrations. The selected table beet mature leaves show slight variations in anatomical structure, especially in the B. vulgaris L. cv. Detroit Dark Red under the highest salinity concentration (4000 ppm) was less than that of the control and the other two cultivars. Other cultivars may be the subject in the near future to study the effect of their salinity tolerance with the aim of increasing productivity, enhancing their characteristics, and preserving the environment.

Assessment of Groundwater Quality in the Semi-Arid Environment: Implications of Climate Change

The hydrogeochemical properties and evolution of groundwater in the Essaouira syncline basin in northwestern Morocco were investigated in this study, with a total of 447 samples during different campaigns (April 2017, May 2018, March 2019, and July 2020). These samples were analyzed for major ions and stable and radioactive water isotopes (δ2H, δ18O, and 3H). With decreasing rainfall from climate change in Morocco, it is crucial to assess the sustainability of groundwater reserves. This shortage leads to the degradation of water and soil quality. To ensure sustainable water management and preserve the environment in the study area, it is necessary to assess groundwater quality for drinking and irrigation, take precautions, and establish management plans. This study assessed groundwater quality using two water quality index methods (WQI and IWQI). Several natural processes control groundwater mineralization, including the dissolution of evaporite and carbonate minerals, cation exchange phenomena, evaporation, and seawater intrusion. According to the results obtained using the WQI method, all groundwater samples in the study area are generally of poor quality and must be treated before being used for domestic purposes. Based on the results obtained by the IWQI method, the samples are suitable for use as irrigation water, especially for plants resistant to high salinity concentrations. Stable isotope measurements (δ2H and δ18O) indicate that Atlantic precipitation continuously recharges the recharge areas of the Essaouira Basin. Thus, the low values of tritium (3H) in groundwater mean that the freshwater in the Essaouira Basin is ancient.

Treatment of sugarcane vinasse in AnMBR and UASB: process performance and microbial community comparison.

Vinasse is a by-product of sugarcane processing which is often used in fertigation; however, the direct use of vinasse harms the environment and reduces soil productivity due to its physicochemical properties. Anaerobic digestion (AD) offers an alternative to mitigate part of the negative effects. Anaerobic high-rate reactors, which mainly rely on sludge granulation, are mostly used in AD of vinasse wastewater. However, the composition of vinasse such as high concentration of solids and organic matter, high salinity, low pH, and high concentrations of sulfate, affect granule formation, leading to sludge washout. Anaerobic membrane bioreactors (AnMBR) present an alternative for vinasse treatment, eliminating the need for sludge granulation and producing a nutrient-rich effluent with minimal residual organics and no suspended solids. Research on sugarcane vinasse treatment using AnMBRs is limited. Most studies have employed submerged internal membrane modules, highlighting the need for further research with different reactor configurations to enhance process performance. In this study, an AnMBR equipped with an external inside-out crossflow ultrafiltration membrane was compared to an upflow anaerobic sludge blanket (UASB) reactor for the treatment of sugarcane vinasse. At a volumetric organic loading rate of up to 6g COD. L-1.d-1, the UASB reactor reached 75% ± 7% of COD removal efficiency whereas the AnMBR generated a solids-free effluent and reached 88% ± 2% of COD removal efficiency. Microorganisms such as Clostridia, Bacteroidia, Mesotaga, Syner-01, Dehalococcoidia, Bacteroidia-DMER64, and Methanolinea were found as the most abundant. The results highlight the AnMBR potential as an effective alternative for treating sugarcane vinasse while overcoming the challenges posed by unsatisfactory sludge granulation.

Squid-Inspired Anti-Salt Skin-Like Elastomers With Superhigh Damage Resistance for Aquatic Soft Robots.

Cephalopod skins evolve multiple functions in response to environmental adaptation, encompassing nonlinear mechanoreponse, damage tolerance property, and resistance to seawater. Despite tremendous progress in skin-mimicking materials, the integration of these desirable properties into a single material system remains an ongoing challenge. Here, drawing inspiration from the structure of reflectin proteins in cephalopod skins, a long-term anti-salt elastomer with skin-like nonlinear mechanical properties and extraordinary damage resistance properties is presented. Cation-π interaction is incorporated to induce the geometrically confined nanophases of hydrogen bond domains, resulting in elastomers with exceptional true tensile strength (456.5 ± 68.9MPa) and unprecedently high fracture energy (103.7 ± 45.7kJ m-2). Furthermore, the cation-π interaction effectively protects the hydrogen bond domains from corrosion by high-concentration saline solution. The utilization of the resultant skin-like elastomer has been demonstrated by aquatic soft robotics capable of grasping sharp objects. The combined advantages render the present elastomer highly promising for salt enviroment applications, particularly in addressing the challenges posed by sweat, in vivo, and harsh oceanic environments.

Optimization of iron, phosphate, and salinity in nutrient medium using response surface methodology for enhancing biochemical composition in Chlorella sp. culture

Microalga Chlorella sp. is a highly scientifically and commercially attractive unicellular microorganism and has developed a stable industry as a nutritional supplement for people and animals. Various nutrient media have been used to grow Chlorella sp. cultures to enhance their growth, pigmentation, and lipid content. However, the optimal biochemical composition and density of Chlorella sp. cultures require an understanding of optimizing the nutrient medium to study their production. The present study aims to investigate the effects of iron, phosphate, and salinity concentrations by working synergically in a nutrient medium on the growth responses, pigments, and lipid accumulation of Chlorella sp. culture using a response surface methodology (RSM) approach. Using the result from the RSM software, a total of 18 experimental groups (E1 – E18) were evaluated, and one confirmation (C) study was conducted. The results revealed that the E7 experiment in Chlorella sp. culture provided the highest cell density and specific growth rate (SGR) with 176.00 × 106 cells mL−1 and 0.35 day−1, respectively. Similarly, the E5 and E1 experiments produced the highest cell density of 166.10 × 106 cells. mL−1 and 152.13 × 106 cells mL−1, respectively. The SGR was also increased at 0.33 day−1 in the E5 experiment and 0.33 day−1 in the E1 experiment. Consequently, the culture of Chlorella sp. containing high iron and phosphate concentrations and lower salinity in a nutrient medium had the highest number of cells, SGR, and pigment accumulation (chlorophyll a and total carotenoid). In addition, the presence of high salinity concentrations reduces Chlorella sp. growth. However, the increase in the growth of Chlorella sp. culture did not indicate an increase in other biochemical compositions. In some cases, biochemical compositions are high due to nutritional limitations or stress factors. For example, in pigment accumulation, chlorophyll a pigment accumulation was increased in experiment E7 (51.57 μg mL−1), while total carotenoid accumulation was increased in experiment E8 (20.68 μg mL−1). In addition, increasing salinity concentration increased chlorophyll a and total carotenoid contents per cell, but decreased Chlorella sp. growth as shown in the E4 experiment, which achieved chlorophyll a levels of 1.38 pg cell−1 and total carotenoid levels of 0.52 pg cell−1. Furthermore, Chlorella sp. culture produces a higher lipid accumulation of 37.38 % in the E3 experiment. Hence, the results of this study contribute to understanding the optimal biochemical composition and cell growth of Chlorella sp. cultures.

Soil Salinity Inversion Based on a Stacking Integrated Learning Algorithm

Soil salinization is an essential risk factor for agricultural development and food security, and obtaining regional soil salinity information more reliably remains a priority problem to be solved. To improve the accuracy of soil salinity inversion, this study focuses on the Manas River Basin oasis area, the largest oasis farming area in Xinjiang, as the study area and proposes a new soil salinity inversion model based on stacked integrated learning algorithms. Firstly, we selected four machine learning regression models, namely, random forest (RF), back propagation neural network, support vector regression, and convolutional neural network, for performance evaluation. Based on the model performance, we selected the more effective RF and BPNN as the basic regression models and further constructed a stacking integrated learning model. This stacking integration learning model improved the prediction accuracy by training a secondary model to fuse the prediction results of these two basic models as new features. We compared and analyzed the stacking integrated learning model with four single machine learning regression models. Findings indicated that the stacking integrated learning regression model fitted better and had good stability; on the test set, the stacking integrated learning regression model showed a relative increase of 8.2% in R2, a relative decrease of 14.0% in RMSE, and a relative increase of 6.5% in RPD when compared to the RF model, which was the single most effective machine learning regression model, and the stacking model was able to achieve soil salinity inversion more accurately. The soil salinity in the oasis areas of the Manas River Basin tended to decrease from north to south from 2016 to 2020 from a spatial point of view, and it was reduced in April from a temporal point of view. The percentage of pixels with a high soil salinity content of 2.75–2.80 g kg−1 in the study area had decreased by 19.6% in April 2020 compared to April 2016. The innovatively constructed stacking integrated learning regression model improved the accuracy of soil salinity estimation on the basis of the superior results obtained in the training of the single optimal machine learning regression model. As a consequence, this model can provide technological backup for fast monitoring and inversion of soil salinity as well as prevention and containment of salinization.

A novel green nanocomposite for EOR: Experimental Investigation of IFT Reduction, wettability Shift, and nanofluid stability

A stable nanofluid (NF) is crucial for success of nano-enhanced oil recovery (nEOR) processes. However, this represents a significant challenge as nanoparticles (NPs) tend to agglomerate under high salinity and NP concentration adversely affecting the oil recovery. New nanomaterials including functionalized nanoparticles also known as nanocomposites (NC) can help to overcome these issues. In this paper, first, we reported synthesis, characterization, and performance evaluation of a novel hydrophobic CuO-SiO2-Montmorillonite-K+-Thiazine NC for the first time. The NC was characterized using Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Analysis (EDAX), X-Ray Diffraction (XRD), Thermogravimetry Analysis (TGA), and Fourier Transform Infrared Spectroscopy (FTIR). SEM analysis showed that the NC is composed of uniformly distributed NPs. EDAX results confirmed presence of Cu, SiO2, O2, and Cl in the NC. XRD analysis indicated that SiO2 is the dominant phase in the crystal lattice and responsible for adsorption capacity of the NC. TGA analysis showed that the NC will be thermally stable in typical reservoir temperatures (∼80°C). FTIR results confirmed presence of Si-O, Cu-O, Si-O-Si, Al-O-Si, Al-OH, and OH bonds in the NC. In the second phase of this research work, the novel NC was used to investigate recovery of a Kazakhstani paraffinic heavy crude oil from Berea sandstone with focus on IFT reduction, oil recovery, wettability alteration, and stability analysis of the NFs. NFs were prepared with NC concentrations of 250, 500, and 1,000 ppm using moderate salinity (MS), low salinity (LS), and distilled water (DW). The results showed that the optimal NF (250 ppm LS) exhibited a high zeta potential value (−65.5 mV) indicating a high stability which is superior to all of the previously reported NCs. This high stability is attributed to use of thaizine as a source of natural surfactant. The optimum NF also altered the wettability of the sandstone by 77.6% and the contact angle (CA) was reduced from 117.9° to 26.4° making the system strongly water wet. The nanoclay has significantly facilitated the wettability alteration. The optimum NF also reduced the IFT by 92.3% from 27.42 mN/m to 2.11 mN/m. An incremental oil recovery of 20% was also achieved in the tertiary or EOR stage of oil. A comparison with the NCs reported in the literature confirmed the excellent performance of this novel NC in terms of NF stability, IFT reduction, and wettability alteration. The novel NC has a great potential for nEOR and other oilfield and environmental applications.

Bionic solar-Driven interfacial evaporator for synergistic photothermal-Photocatalytic activities and salt collection during desalination

Solar-driven interfacial evaporation plays an essential part in the production of potable water. Nevertheless, the intricate water conditions in real-world scenarios continue to pose limitations on its utilization. This study prepared a novel bionic PPy/BiVO4-PI/MXene aerogel composite material with radial center structure through directional freezing as the evaporator, which integrates both photothermal and photocatalytic properties into the evaporation system. In order to evaluate the efficacy of photocatalytic degradation and salt collection during interfacial evaporation, high-concentration saline water, simulated seawater and dyeing wastewater were employed as substitutes for real contaminated water bodies. After being exposed to 1 kW/m−2(−|-) of irradiation, the PPy/BiVO4-PI/MXene composite exhibits an evaporation rate of 1.64 kg m-2h−1 and achieves a photothermal efficiency of 96.77 %. In high-concentration saltwater containing 20 wt% NaCl, the PPy/BiVO4-PI/MXene exhibited an evaporation rate of 1.32 kg m-2h−1 and a photothermal conversion efficiency of 77.41 %. Furthermore, approximately 26.7 g of salt can be collected after 15 days’ continuous evaporation. Furthermore, the PPy/BiVO4-PI/MXene demonstrated exceptional photocatalytic capabilities to organic dyes such as MB, RhB, CR and MG with removal efficiencies of 79.28 %, 70.96 %, 76.70 % and 80.95 %, respectively. This study realizes the synergistic effect of interfacial evaporation, photocatalysis and salt collection, providing a highly promising choice for the treatment of high-salt dyeing wastewaters.

Simultaneous desalination and removal of organic pollutants in a novel bifunctional FCDI system: The enhancement by in-situ reutilization of chloride ions

A new system of flow electrode capacitive deionization coupled with in situ electro-oxidation (FCDI-EO) was constructed to achieve the degradation of organic pollutants while maintaining high desalination efficiency. The effects of different parameters of potential difference, electrolyte, and pH on the chloride removal performance of FCDI-EO and the removal performance of rhodamine B (RhB) were investigated. Under the optimal conditions of potential difference = 4 V, [Cl−] = 500 mg/L, and pH = 4, the removal of chloride ions, RhB and total organic carbon (TOC) was as high as 88.74 %, 99.02 %, and 87.82 %, respectively. The quenching experiments showed that hydroxyl radicals (OH) and reactive chlorine species (RCS) were involved in the FCDI-EO system. The liquid chromatography-mass spectrometry (LC-MS) analysis suggested the possible mineralization pathway of RhB. Furthermore, toxicity assessment analysis showed that the toxicity of the degradation intermediates of RhB decreased during the treatment. Overall, this study provides a promising process that reducing the generation of high-concentration saline water in desalination and in situ utilizing the Cl− gathered from the feed water. The findings of this study could provide useful guidance for the development of flow electrode capacitive deionization technology and organic pollutant control.

Preparation of double network antibacterial hydrogel modified by hydroxamic acid gelatin/polyacrylamide and high efficiency uranium extraction from seawater

Uranium extracted from seawater can solve the problem of the shortage of uranium on land and provide potential resources for the nuclear power industry. However, the high salinity and low uranium concentration in seawater, coupled with the presence of competing ions and bacteria, pose significant challenges to this technology. In this study, a hydroxyl oxime acid modified gelatin/polyacrylamide double network (Gel/PAM(DN)-HA) hydrogel developed for efficient uranium extraction from seawater. The adsorption capacity of Gel/PAM(DN)-HA hydrogel for uranium in 15 ppm uranium solution was as high as 397.04 mg-U/g-Ads, with a reuse rate of 78.46 % ± 5.84 % after 5 cycles of adsorption-desorption. Gel/PAM(DN)-HA was immersed in natural seawater for 24 days to evaluate its adsorption capacity. Gel/PAM(DN)-HA demonstrated an impressive uranium extraction capacity of 4.801 mg·g−1. Antibacterial experiments demonstrated that Gel/PAM(DN)-HA can effectively inhibit the Escherichia coli (E. coli ATCC25922) and Staphylococcus aureus (S. aureus ATCC6538). The results highlight the adsorbent's significant potential for extensive utilization in extracting uranium from seawater.

Entomoneis parikhani sp.nov., Aras Nehri (İran)’nden yeni bir diatom (Entomoneidaceae, Bacillariophyta)

The diatom Entomoneis has a series of unique features such as connecting lines with different shapes, sigmoid raphe on the bilobate keel, different curtains, and multiple girdle bands. Most species belonging to this genus are found in marine and saline habitats. In fact, the genus Entomoneis is an epipelic diatom that is found in streams with high salinity and high electrolyte concentration. To date, no specific type of freshwater has been identified for this species. In this study, a new species of freshwater diatom, Entomoneis parikhani, is described based on detailed morphological observations using a scanning electron microscope. The samples were collected the Aras River near Oltan village of Parsabad city in the northwest Iran. A special feature of Entomoneis parikhani is its triple valve. The genus Entomoneis comprises of diatoms with sigmoidal raphe canals and girdle bands. This taxon is similar to Entomoneis annagodhei and Entomoneis tenera, as shown by LM and SEM observations, and there are sufficient morphological differences to separate Entomoneis parikhani. This new species had very small cells, delicate frustules without valve lines, and wide lanceolate valves. In this study, the wide distribution of this taxon in the Aras River has been evaluated.

Differential salt stress resistance in male and female Salix linearistipularis plants: insights from transcriptome profiling and the identification of the 4-hydroxy-tetrahydrodipicolinate synthase gene.

Lysine plays an essential role in the growth differences between male and female S. linearistipularis plants under salt stress. Furthermore, SlDHDPS is identified as a vital gene contributing to the differences in saline-alkali tolerance between male and female plants of S. linearistipularis. Soil salinization is a significant problem that severely restricts agricultural production worldwide. High salinity and low nutrient concentrations consequently prevent the growth of most plant species. Salix linearistipularis is the only woody plant (shrub) naturally distributed in the saline-alkali lands of the Songnen Plain in Northeast China, and it is one of the few plants capable of thriving in soils with extremely high salt and alkaline pH (>9.0) levels. However, insufficient attention has been given to the interplay between salt and nitrogen in the growth and development of S. linearistipularis. Here, the male and female plants of S. linearistipularis were subjected to salt stress with nitrogen-starvation or nitrogen-supplement treatments, and it was found that nitrogen significantly affects the difference in salt tolerance between male and female plants, with nitrogen-starvation significantly enhancing the salt stress tolerance of female plants compared to male plants. Transcriptional analyses showed 66 differentially expressed nitrogen-responsive genes in female and male roots, with most of them showing sexual differences in expression patterns under salinity stress. RNA-seq and RT-qPCR analysis demonstrated that six genes had an opposite salt-induced expression pattern in female and male roots. The expression of the 4-hydroxy-tetrahydrodipicolinate synthase encoding gene (SlDHDPS) in female roots was higher than that in male roots. Further treatment with exogenous lysine could significantly alleviate the inhibitory effect of salt stress on the growth of female and male plants. These results indicate that the SlDHDPS in the nitrogen metabolism pathway is involved in the resistance of S. linearistipularis to salt stress, which lays a foundation for further exploring the mechanism of nitrogen on salt tolerance of S. linearistipularis, and has a significant reference value for saline-alkali land management and sustainable agricultural development.

Efficient bioremediation of multiple steroid hormones by halotolerant 17β-hydroxysteroid dehydrogenase derived from moderately halophilic Pontibacillus chungwhensis HN14.

Steroid hormones exhibit potent endocrine disrupting activity and have been shown to disrupt the equilibrium of aquatic ecosystems and pose a threat to public health through their persistent and carcinogenic effects. Pontibacillus chungwhensis HN14, a moderately halophilic bacterium with the capacity to effectively degrade various polycyclic aromatic hydrocarbons and other organic pollutants, was previously isolated. Additionally, the strain HN14 showed strong environmental adaptability under various environmental stress conditions. In this study, the steroid degradation by strain HN14 was studied for the first time. We demonstrated that strain HN14 could degrade estradiol (E2) to maintain the growth of the strain and could convert E2 to estrone. Additionally, the efficient substrate degradation efficiency of P. chungwhensis HN14 under high salinity and high substrate concentration conditions was demonstrated. Furthermore, a 17β-hydroxysteroid dehydrogenase, 17β-HSD(HN14), was identified in strain HN14. Comparative analysis reveals that 17β-HSD(HN14) shares approximately 38% sequence identity with 17β-HSDx from Rhodococcus sp. P14. In addition, 100µg of purified 17β-HSD(HN14) could effectively convert about 40% of 0.25 mM of E2 within 1h period, with an enzyme activity of 17.5 U/mg, and catalyze the dehydrogenation of E2 and testosterone at the C-17 position. The characterization of purified enzyme properties reveals that 17β-HSD(HN14) exhibits exceptional structural robustness and enzymatic efficacy even under high salinity conditions of up to 20%. Overall, this study enhances our comprehension of steroid biodegradation in strain HN14 and contributes novel ideas and theoretical underpinnings for advancing bioremediation technologies targeting steroid pollution in high-saline environments.

Low-toxicity natural pyrite on electro-Fenton catalytic reaction in a wide pH range

The resource utilization of natural pyrite not only reduces secondary pollution but also brings certain environmental benefits. However, the green and efficient use of pyrite presents certain challenges. In this study, a novel electro-Fenton (EF) system was constructed utilizing copper modified graphite felt (GF/Cu) as cathode and natural pyrite (com-FeS2) as catalyst. The results demonstrated that the system exhibited a remarkable stability over an extensive pH range (3.0–10.0) and remained effective even under adverse environmental conditions, such as high salinity or elevated antibiotic concentration. After optimizing the reaction conditions, 0.2 mM sulfamerazine (SMZ) was almost completely degraded within 1.5 h. The results highlighted the catalytic role of Fe(II) on the com-FeS2 surface. Combined with quenching experiments and quantitative analysis of reactive oxygen species (ROS), the removal of SMZ was primarily attributed to the generation of •OH, ordered by 1O2 > •O2− > •OHads, a possible degradation pathway was proposed by HR-LC-MS. The biological toxicity after the reaction was detected, and the introduction of polyvinylpyrrolidone (PVP) was beneficial to reduce the biological toxicity of iron dissolution. This work provides new insights into the green and efficient resource utilization of natural pyrite and significantly expands the pH applicability range of the Fenton process, demonstrating the large-scale industrial application potential of pyrite.

Production performance and biochemical profile of sea lettuce (Ulva lactuca): Influence of site-specific ecological factors and cultivation strategies

Production performance and biochemical characteristics of seaweed under varying cultivation strategies and ecological conditions provide crucial insights for improving sustainable farming practices. Therefore, this study aims to investigate the production performance and biochemical profile of sea lettuce (Ulva lactuca) under three farming systems, namely floating long-line (FLL), off-bottom long-line (OBLL), and off-bottom net (OBN), and three site-specific (Khurushkul, Nuniachora, and Sonapara) ecological conditions for a period of nine months (October 2022 to June 2023). Depending on the site suitability for different cultivation systems, 15 plots (5 FLL, 5 OBLL, and 5 OBN) were established in Nuniachora, 10 plots (5 FLL, 5 OBLL) were established in Sonapara, and 5 plots (FLL) were established in Khurushkul of the Cox's Bazar district, Bangladesh. Depending on the cultivation months, we partially harvested U. lactuca every 15–30 days once it reached 25–35 cm in length. Results showed that the gross weight biomass (GWB) of U. lactuca cultured in the FLL (F = 200.43, p < 0.001) cultivation system was 45.38% and 39.85% higher compared to OBN and OBLL, respectively. The average daily growth rate (DGR) was found to be 11%–13% higher in the FLL method (F = 236.11, p < 0.001). Location-based comparisons indicated a significantly higher (p < 0.05) U. lactuca production in Khurushkul, followed by the Nuniarchora, and the lowest was observed in Sonapara. Seasonality influenced the production performances of U. lactuca, with significantly higher (p < 0.05) growth observed from December to March due to favourable physio-chemical parameters. Multivariate analysis revealed that high salinity, pH, and nutrient concentrations positively influenced growth performances, while high temperature, turbidity, and total suspended solids (TSS) had negative effects. U. lactuca harvested from the FLL and OBN systems contained 14.3% and 9.44% higher amounts of protein (F = 36.77, p < 0.001) than the OBN system. The fatty acid analysis showed that U. lactuca from the FLL and OBN systems contained a significantly lower amount of saturated fatty acids but a higher amount of monounsaturated and n-6 polyunsaturated fatty acids compared to the OBLL system. Among the heavy metals and minerals analyzed, U. lactuca harvested from the FLL system contained significantly (p < 0.05) higher amounts of Na and K and lower amounts of Pb, Cr, Co, and Fe. The findings of the present study underscore the superiority of the floating long-line cultivation system for U. lactuca, highlighting its potential for sustainable farming practices to address global food security and utilization in various industrial applications.

Efficient treatment of high-concentration pharmaceutical wastewater with high-salinity by chemical synthesis coupling with evaporation: From lab-scale to pilot-scale

This study focused on the treatment of high-concentration pharmaceutical wastewater with high-salinity by pretreatment of chemical synthesis coupling with evaporation. Via chemical synthesis, this pretreatment process was developed to remove the organic matter that inhibited evaporation of wastewater, resulting in improved evaporation efficiency. Lab-scale results demonstrated that under the optimum conditions (∼pH 9, 2 mL/L demulsifier, 98 mM/L H2O2, 3 h of aeration time, 80 °C, 500 mg/L PAC, and 20 mg/L PAM), 54.9 % of COD was successfully removed by single pretreatment and 98.6 % after coupling with evaporation. Compared to the 80.1 % COD removal efficiency of direct evaporation of 100 mL with 30 min, the pretreatment process coupling with evaporation demonstrated superior performance and halved the evaporation time. A pilot-scale chemical synthesis pretreatment (120 t/d) was further developed to treat pharmaceutical wastewater of both high COD concentrations and high salinity. Under the optimal conditions determined in the lab-scale experiments, the pilot-scale achieved a COD removal efficiency of 49 % with a single pretreatment and 95.8 % after coupling with mechanical vapor recompression (MVR). Additionally, the obtained salt appeared visually clean and white compared to that obtained from the treated wastewater without pretreatment. Furthermore, to elucidate the possible mechanisms driving the efficient removal of COD, GC–MS was performed on the wastewater before and after pretreatment, and the resulting products from pretreatment in pilot-scale applications were further determined by both FTIR and GC–MS. It was proposed that the aldol condensation reaction increased the formation of carbon chains to macromolecular compounds might be the possible mechanism. This study gives insights into the future application of low-investment and low-cost technology in the treatment of high-concentration pharmaceutical wastewater with high salinity in industry.

NITROGEN LIMITATION AND CHANGES IN SALINITY AFFECTS CHEMICAL-PROXIMATE-COMPOSITION OF Thalassiosira weissflogii

Microalgae are a crucial factor in aquaculture activities, since they are used as live food in the larvae stage of shrimp, mollusks, and fish. Nevertheless, just a few microalga species are produce. In this study we evaluate the effect of salinity at 25, 35, 45 and 55 practical salinity unit (psu), in F/2 media as control group and two nitrogen (NaNO3) limited media, F/4 and F/8 on the diatom Thalassiosira weissflogii. To value the development of the diatom, kinetic growth curves, pH, biomass production and chemical-proximate composition were estimated. The highest growth rate and organic matter values were in media F/4 and 35 psu. Meanwhile, media F/8 at 55 psu presented the highest amount of ash and a very low growth rate. T. weissflogii is affected by high salinity concentration, however the limitation of nitrogen with 25 and 35 psu did not affect growth considerably. Concerning the chemical-proximate composition of T. weissflogii, media F/4 at 25 psu, presented the highest percentages of carbohydrates and proteins. In the same way, medium F2 at 25 psu, reported the highest amounts of carotenes. The results showed that high salinity was the variable that major affected the cell density, biomass production and chemical-proximate composition of T. weissflogii.

Effect of Salt Stress on Growth and Yield of Plants: A Review

Abstract Soil salinity is a major abiotic stressor, severely restricting plant growth and yield. It negatively impacts every stage, from seed germination and seedling development to flowering and fruit formation, consequently lowering both quantity and quality of produce. The reasons for this may be due to the fact that salinity affects photosynthesis enzymes, chlorophyll, carotenoids, changes in water potential, leaf swelling pressure, and others. Accordingly, plants were classified into salt-sensitive (Glycophytes) and salt-tolerant (Haplophytes) this depends on its ability to grow in different salt concentrations. High concentrations of salinity in the soil contribute to reducing the osmotic stress of the soil solution and cause water stress for plants. It also causes toxicity as a result of increased concentrations of some elements, such as sodium, as it is not easily isolated within the vacuoles. Also, the reaction between salt and nutrients causes a nutritional imbalance. Adaptation to salt stress includes many processes, including an increase in ABA content, accumulation of solutes such as amino acids and sugars, protective proteins such as (PRD) disease-related proteins, increased antioxidants, and suppression of energy expenditure pathways. These solutes that accumulate under salt stress may be involved in removing ROS. Non-structural carbohydrates also accumulate, such as (sucrose, hexose, and sugar alcohols). These sugars act in a protective role as they contribute to maintaining the stability of the membrane. One of the important amino acids that increases during salt stress is proline, which plays the role of protecting the integrity of the membrane. Plasma and energy production.

Inversion Method for Chlorophyll-a Concentration in High-Salinity Water Based on Hyperspectral Remote Sensing Data.

As one of the important lakes in the "One Lake and Two Seas" of the Inner Mongolia Autonomous Region, the monitoring of water quality in Lake Daihai has attracted increasing attention, and the concentration of chlorophyll-a directly affects the water quality, making the monitoring of chlorophyll-a concentration in Lake Daihai particularly crucial. Traditional methods of monitoring chlorophyll-a concentration are not only inefficient but also require significant human and material resources. Remote sensing technology has the advantages of wide coverage and short update cycles. For lakes such as Daihai with a high salinity content, salinity is considered a key factor when inverting the concentration of chlorophyll-a. In this study, machine learning models, including model stacking from ensemble learning, a ridge regression model, and a random forest model, were constructed. After comparing the training accuracy of the three models on Zhuhai-1 satellite data, the random forest model, which had the highest accuracy, was selected as the final training model. By comparing the accuracy changes before and after adding salinity factors to the random forest model, a high-precision model for inverting chlorophyll-a concentration in hypersaline lakes was obtained. The research results show that, without considering the salinity factor, the root mean square error (RMSE) of the model was 0.056, and the coefficient of determination (R2) was 0.64, indicating moderate model performance. After adding the salinity factor, the model accuracy significantly improved: the RMSE decreased to 0.047, and the R2 increased to 0.92. This study provides a solid basis for the application of remote sensing technology in hypersaline aquatic environments, confirming the importance of considering salinity when estimating chlorophyll-a concentration in hypersaline waters. This research helps us gain a deeper understanding of the water quality and ecosystem evolution in Daihai Lake.